Version 3.35.4

FossilOrigin-Name: 5d4c65779dab868b285519b19e4cf9d451d50c6048f06f653aa701ec212df45e
Fix incorrect RETURNING test cases in wherelimit.test
2021-04-02 15:20:15 +00:00 · 2021-04-02 11:59:23 +00:00 · 2021-04-01 11:30:23 +00:00 · 2021-03-31 17:49:52 +00:00 · 2021-03-31 13:51:07 +00:00 · 2021-03-31 13:41:10 +00:00
367 changed files with 27970 additions and 5649 deletions
@@ -440,9 +440,12 @@ TESTSRC += \
  $(TOP)/ext/expert/sqlite3expert.c \
  $(TOP)/ext/expert/test_expert.c \
  $(TOP)/ext/misc/amatch.c \
+  $(TOP)/ext/misc/appendvfs.c \
  $(TOP)/ext/misc/carray.c \
+  $(TOP)/ext/misc/cksumvfs.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/csv.c \
+  $(TOP)/ext/misc/decimal.c \
  $(TOP)/ext/misc/eval.c \
  $(TOP)/ext/misc/explain.c \
  $(TOP)/ext/misc/fileio.c \
@@ -619,6 +622,7 @@ FUZZCHECK_OPT += -DSQLITE_MAX_MEMORY=50000000
 FUZZCHECK_OPT += -DSQLITE_PRINTF_PRECISION_LIMIT=1000
 FUZZCHECK_OPT += -DSQLITE_ENABLE_DESERIALIZE
 FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS4
+FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS3_PARENTHESIS
 #FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS5
 FUZZCHECK_OPT += -DSQLITE_ENABLE_RTREE
 FUZZCHECK_OPT += -DSQLITE_ENABLE_GEOPOLY
@@ -1066,6 +1070,12 @@ parse.c:	$(TOP)/src/parse.y lemon$(BEXE)
 sqlite3.h:	$(TOP)/src/sqlite.h.in $(TOP)/manifest mksourceid$(BEXE) $(TOP)/VERSION
 	$(TCLSH_CMD) $(TOP)/tool/mksqlite3h.tcl $(TOP) >sqlite3.h

+sqlite3rc.h:	$(TOP)/src/sqlite3.rc $(TOP)/VERSION
+	echo '#ifndef SQLITE_RESOURCE_VERSION' >$@
+	echo -n '#define SQLITE_RESOURCE_VERSION ' >>$@
+	cat $(TOP)/VERSION | $(TCLSH_CMD) $(TOP)/tool/replace.tcl exact . , >>$@
+	echo '#endif' >>sqlite3rc.h
+
 keywordhash.h:	$(TOP)/tool/mkkeywordhash.c
 	$(BCC) -o mkkeywordhash$(BEXE) $(OPT_FEATURE_FLAGS) $(OPTS) $(TOP)/tool/mkkeywordhash.c
 	./mkkeywordhash$(BEXE) >keywordhash.h
@@ -1074,9 +1084,12 @@ keywordhash.h:	$(TOP)/tool/mkkeywordhash.c
 SHELL_SRC = \
 	$(TOP)/src/shell.c.in \
        $(TOP)/ext/misc/appendvfs.c \
-	$(TOP)/ext/misc/shathree.c \
-	$(TOP)/ext/misc/fileio.c \
 	$(TOP)/ext/misc/completion.c \
+        $(TOP)/ext/misc/decimal.c \
+	$(TOP)/ext/misc/fileio.c \
+        $(TOP)/ext/misc/ieee754.c \
+        $(TOP)/ext/misc/series.c \
+	$(TOP)/ext/misc/shathree.c \
 	$(TOP)/ext/misc/sqlar.c \
        $(TOP)/ext/misc/uint.c \
 	$(TOP)/ext/expert/sqlite3expert.c \
@@ -1222,6 +1235,7 @@ TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_STMTVTAB
 TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_DBPAGE_VTAB
 TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_BYTECODE_VTAB
 TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_DESERIALIZE
+TESTFIXTURE_FLAGS += -DSQLITE_CKSUMVFS_STATIC

 TESTFIXTURE_SRC0 = $(TESTSRC2) libsqlite3.la
 TESTFIXTURE_SRC1 = sqlite3.c
@@ -1254,7 +1268,7 @@ fuzztest:	fuzzcheck$(TEXE) $(FUZZDATA) sessionfuzz$(TEXE) $(TOP)/test/sessionfuz
 	./sessionfuzz$(TEXE) run $(TOP)/test/sessionfuzz-data1.db

 valgrindfuzz:	fuzzcheck$(TEXT) $(FUZZDATA) sessionfuzz$(TEXE) $(TOP)/test/sessionfuzz-data1.db
-	valgrind ./fuzzcheck$(TEXE) --cell-size-check --limit-mem 10M --timeout 600 $(FUZZDATA)
+	valgrind ./fuzzcheck$(TEXE) --cell-size-check --limit-mem 10M $(FUZZDATA)
 	valgrind ./sessionfuzz$(TEXE) run $(TOP)/test/sessionfuzz-data1.db

 # The veryquick.test TCL tests.
@@ -1285,6 +1299,9 @@ valgrindtest:	$(TESTPROGS) valgrindfuzz
 smoketest:	$(TESTPROGS) fuzzcheck$(TEXE)
 	./testfixture$(TEXE) $(TOP)/test/main.test $(TESTOPTS)

+shelltest: $(TESTPROGS)
+	./testfixture$(TEXT) $(TOP)/test/permutations.test shell
+
 sqlite3_analyzer.c: sqlite3.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in
 	$(TCLSH_CMD) $(TOP)/tool/mkccode.tcl $(TOP)/tool/sqlite3_analyzer.c.in >sqlite3_analyzer.c

@@ -1362,6 +1379,9 @@ wordcount$(TEXE):	$(TOP)/test/wordcount.c sqlite3.lo
 speedtest1$(TEXE):	$(TOP)/test/speedtest1.c sqlite3.c
 	$(LTLINK) $(ST_OPT) -o $@ $(TOP)/test/speedtest1.c sqlite3.c $(TLIBS)

+startup$(TEXE):	$(TOP)/test/startup.c sqlite3.c
+	$(CC) -Os -g -DSQLITE_THREADSAFE=0 -o $@ $(TOP)/test/startup.c sqlite3.c $(TLIBS)
+
 KV_OPT += -DSQLITE_DIRECT_OVERFLOW_READ

 kvtest$(TEXE):	$(TOP)/test/kvtest.c sqlite3.c
@@ -1387,10 +1407,10 @@ checksymbols: sqlite3.o
 # a tarball named for the version number.  Ex:  sqlite-autoconf-3110000.tar.gz.
 # The snapshot-tarball target builds a tarball named by the SHA1 hash
 #
-amalgamation-tarball: sqlite3.c
+amalgamation-tarball: sqlite3.c sqlite3rc.h
 	TOP=$(TOP) sh $(TOP)/tool/mkautoconfamal.sh --normal

-snapshot-tarball: sqlite3.c
+snapshot-tarball: sqlite3.c sqlite3rc.h
 	TOP=$(TOP) sh $(TOP)/tool/mkautoconfamal.sh --snapshot

 # The next two rules are used to support the "threadtest" target. Building
@@ -234,6 +234,15 @@ OSTRACE = 0
 DEBUG = 0
 !ENDIF

+# <<mark>>
+# Disable use of the --linemacros argument to the mksqlite3c.tcl tool, which
+# is used to build the amalgamation.
+#
+!IFNDEF NO_LINEMACROS
+NO_LINEMACROS = 0
+!ENDIF
+# <</mark>>
+
 # Enable use of available compiler optimizations?  Normally, this should be
 # non-zero.  Setting this to zero, thus disabling all compiler optimizations,
 # can be useful for testing.
@@ -371,6 +380,9 @@ OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_SESSION=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_PREUPDATE_HOOK=1
 !ENDIF

+# Always enable math functions on Windows
+OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_MATH_FUNCTIONS
+
 # Should the rbu extension be enabled?  If so, add compilation options
 # to enable it.
 #
@@ -776,7 +788,7 @@ MKSQLITE3C_TOOL = $(TOP)\tool\mksqlite3c.tcl
 !ENDIF

 !IFNDEF MKSQLITE3C_ARGS
-!IF $(DEBUG)>1
+!IF $(DEBUG)>1 && $(NO_LINEMACROS)==0
 MKSQLITE3C_ARGS = --linemacros
 !ELSE
 MKSQLITE3C_ARGS =
@@ -1247,7 +1259,8 @@ LIBOBJS0 = vdbe.lo parse.lo alter.lo analyze.lo attach.lo auth.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
         update.lo upsert.lo util.lo vacuum.lo \
         vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
-         vdbetrace.lo wal.lo walker.lo where.lo wherecode.lo whereexpr.lo \
+         vdbetrace.lo vdbevtab.lo wal.lo walker.lo where.lo wherecode.lo \
+         whereexpr.lo \
         window.lo utf.lo vtab.lo
 # <</mark>>

@@ -1485,7 +1498,7 @@ SRC12 =

 # All source code files.
 #
-SRC = $(SRC00) $(SRC01) $(SRC03) $(SRC04) $(SRC05) $(SRC06) $(SRC07) $(SRC08) $(SRC09) $(SRC10) $(SRC11)
+SRC = $(SRC00) $(SRC01) $(SRC03) $(SRC04) $(SRC05) $(SRC06) $(SRC07) $(SRC08) $(SRC09) $(SRC10) $(SRC11) $(SRC12)

 # Source code to the test files.
 #
@@ -1547,9 +1560,12 @@ TESTEXT = \
  $(TOP)\ext\expert\sqlite3expert.c \
  $(TOP)\ext\expert\test_expert.c \
  $(TOP)\ext\misc\amatch.c \
+  $(TOP)\ext\misc\appendvfs.c \
  $(TOP)\ext\misc\carray.c \
+  $(TOP)\ext\misc\cksumvfs.c \
  $(TOP)\ext\misc\closure.c \
  $(TOP)\ext\misc\csv.c \
+  $(TOP)\ext\misc\decimal.c \
  $(TOP)\ext\misc\eval.c \
  $(TOP)\ext\misc\explain.c \
  $(TOP)\ext\misc\fileio.c \
@@ -1836,15 +1852,16 @@ mptest:	mptester.exe
 	for %i in ($(SRC11)) do copy /Y %i tsrc
 	for %i in ($(SRC12)) do copy /Y %i tsrc
 	copy /Y fts5.c tsrc
+	copy /B tsrc\fts5.c +,,
 	copy /Y fts5.h tsrc
+	copy /B tsrc\fts5.h +,,
 	del /Q tsrc\sqlite.h.in tsrc\parse.y 2>NUL
 	$(TCLSH_CMD) $(TOP)\tool\vdbe-compress.tcl $(OPTS) < tsrc\vdbe.c > vdbe.new
 	move vdbe.new tsrc\vdbe.c
 	echo > .target_source

-sqlite3.c:	.target_source sqlite3ext.h $(MKSQLITE3C_TOOL)
+sqlite3.c:	.target_source sqlite3ext.h sqlite3session.h $(MKSQLITE3C_TOOL)
 	$(TCLSH_CMD) $(MKSQLITE3C_TOOL) $(MKSQLITE3C_ARGS)
-	copy $(TOP)\ext\session\sqlite3session.h .

 sqlite3-all.c:	sqlite3.c $(TOP)\tool\split-sqlite3c.tcl
 	$(TCLSH_CMD) $(TOP)\tool\split-sqlite3c.tcl
@@ -1859,7 +1876,8 @@ sqlite3.lo:	$(SQLITE3C)
 # Rules to build the LEMON compiler generator
 #
 lempar.c:	$(TOP)\tool\lempar.c
-	copy $(TOP)\tool\lempar.c .
+	copy /Y $(TOP)\tool\lempar.c .
+	copy /B lempar.c +,,

 lemon.exe:	$(TOP)\tool\lemon.c lempar.c
 	$(BCC) $(NO_WARN) -Daccess=_access \
@@ -2159,7 +2177,8 @@ parse.h:	parse.c

 parse.c:	$(TOP)\src\parse.y lemon.exe
 	del /Q parse.y parse.h parse.h.temp 2>NUL
-	copy $(TOP)\src\parse.y .
+	copy /Y $(TOP)\src\parse.y .
+	copy /B parse.y +,,
 	.\lemon.exe $(REQ_FEATURE_FLAGS) $(OPT_FEATURE_FLAGS) $(EXT_FEATURE_FLAGS) $(OPTS) -S parse.y

 $(SQLITE3H):	$(TOP)\src\sqlite.h.in $(TOP)\manifest mksourceid.exe $(TOP)\VERSION
@@ -2172,8 +2191,13 @@ sqlite3ext.h:	.target_source
 	copy /Y sqlite3ext.h tsrc\sqlite3ext.h
 !ELSE
 	copy /Y tsrc\sqlite3ext.h sqlite3ext.h
+	copy /B sqlite3ext.h +,,
 !ENDIF

+sqlite3session.h:	$(TOP)\ext\session\sqlite3session.h
+	copy /Y $(TOP)\ext\session\sqlite3session.h .
+	copy /B sqlite3session.h +,,
+
 mkkeywordhash.exe:	$(TOP)\tool\mkkeywordhash.c
 	$(BCC) $(NO_WARN) -Fe$@ $(REQ_FEATURE_FLAGS) $(OPT_FEATURE_FLAGS) $(EXT_FEATURE_FLAGS) $(OPTS) \
 		$(TOP)\tool\mkkeywordhash.c /link $(LDFLAGS) $(NLTLINKOPTS) $(NLTLIBPATHS)
@@ -2185,10 +2209,13 @@ keywordhash.h:	$(TOP)\tool\mkkeywordhash.c mkkeywordhash.exe
 SHELL_SRC = \
 	$(TOP)\src\shell.c.in \
 	$(TOP)\ext\misc\appendvfs.c \
-	$(TOP)\ext\misc\shathree.c \
-	$(TOP)\ext\misc\fileio.c \
 	$(TOP)\ext\misc\completion.c \
-        $(TOP)\ext\misc\uint.c \
+        $(TOP)\ext\misc\decimal.c \
+	$(TOP)\ext\misc\fileio.c \
+        $(TOP)\ext\misc\ieee754.c \
+        $(TOP)\ext\misc\series.c \
+	$(TOP)\ext\misc\shathree.c \
+	$(TOP)\ext\misc\uint.c \
 	$(TOP)\ext\expert\sqlite3expert.c \
 	$(TOP)\ext\expert\sqlite3expert.h \
 	$(TOP)\ext\misc\memtrace.c \
@@ -2319,7 +2346,8 @@ LSM1_SRC = \
   $(TOP)\ext\lsm1\lsm_win32.c

 fts5parse.c:	$(TOP)\ext\fts5\fts5parse.y lemon.exe
-	copy $(TOP)\ext\fts5\fts5parse.y .
+	copy /Y $(TOP)\ext\fts5\fts5parse.y .
+	copy /B fts5parse.y +,,
 	del /Q fts5parse.h 2>NUL
 	.\lemon.exe $(REQ_FEATURE_FLAGS) $(OPT_FEATURE_FLAGS) $(EXT_FEATURE_FLAGS) $(OPTS) -S fts5parse.y

@@ -2327,11 +2355,13 @@ fts5parse.h:	fts5parse.c

 fts5.c:	$(FTS5_SRC)
 	$(TCLSH_CMD) $(TOP)\ext\fts5\tool\mkfts5c.tcl
-	copy $(TOP)\ext\fts5\fts5.h .
+	copy /Y $(TOP)\ext\fts5\fts5.h .
+	copy /B fts5.h +,,

 lsm1.c:	$(LSM1_SRC)
 	$(TCLSH_CMD) $(TOP)\ext\lsm1\tool\mklsm1c.tcl
-	copy $(TOP)\ext\lsm1\lsm.h .
+	copy /Y $(TOP)\ext\lsm1\lsm.h .
+	copy /B lsm.h +,,

 fts5.lo:	fts5.c $(HDR) $(EXTHDR)
 	$(LTCOMPILE) $(CORE_COMPILE_OPTS) $(NO_WARN) -DSQLITE_CORE -c fts5.c
@@ -2362,6 +2392,7 @@ TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_DBPAGE_VTAB=1
 TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_BYTECODE_VTAB=1
 TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_JSON1=1
 TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_ENABLE_DESERIALIZE=1
+TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_CKSUMVFS_STATIC=1
 TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) $(TEST_CCONV_OPTS)

 TESTFIXTURE_SRC0 = $(TESTEXT) $(TESTSRC2)
@@ -2442,6 +2473,9 @@ smoketest:	$(TESTPROGS)
 	@set PATH=$(LIBTCLPATH);$(PATH)
 	.\testfixture.exe $(TOP)\test\main.test $(TESTOPTS)

+shelltest: $(TESTPROGS)
+	.\testfixture.exe $(TOP)\test\permutations.test shell
+
 sqlite3_analyzer.c:	$(SQLITE3C) $(SQLITE3H) $(TOP)\src\tclsqlite.c $(TOP)\tool\spaceanal.tcl $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in $(SQLITE_TCL_DEP)
 	$(TCLSH_CMD) $(TOP)\tool\mkccode.tcl $(TOP)\tool\sqlite3_analyzer.c.in > $@

@@ -1 +1 @@
-3.32.0
+3.35.4
@@ -13,7 +13,7 @@ sqlite3_CFLAGS = $(AM_CFLAGS) -DSQLITE_ENABLE_EXPLAIN_COMMENTS -DSQLITE_ENABLE_D

 include_HEADERS = sqlite3.h sqlite3ext.h

-EXTRA_DIST = sqlite3.1 tea Makefile.msc sqlite3.rc README.txt Replace.cs Makefile.fallback
+EXTRA_DIST = sqlite3.1 tea Makefile.msc sqlite3.rc sqlite3rc.h README.txt Replace.cs Makefile.fallback
 pkgconfigdir = ${libdir}/pkgconfig
 pkgconfig_DATA = sqlite3.pc

@@ -196,6 +196,7 @@ OSTRACE = 0
 DEBUG = 0
 !ENDIF

+
 # Enable use of available compiler optimizations?  Normally, this should be
 # non-zero.  Setting this to zero, thus disabling all compiler optimizations,
 # can be useful for testing.
@@ -288,6 +289,7 @@ OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_JSON1=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_STMTVTAB=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DBPAGE_VTAB=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DBSTAT_VTAB=1
+OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_BYTECODE_VTAB=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_DESERIALIZE=1
 !ENDIF
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_COLUMN_METADATA=1
@@ -301,6 +303,9 @@ OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_SESSION=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_PREUPDATE_HOOK=1
 !ENDIF

+# Always enable math functions on Windows
+OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_MATH_FUNCTIONS
+
 # Should the rbu extension be enabled?  If so, add compilation options
 # to enable it.
 #
@@ -87,7 +87,9 @@ AC_SUBST(READLINE_LIBS)
 AC_ARG_ENABLE(threadsafe, [AS_HELP_STRING(
  [--enable-threadsafe], [build a thread-safe library [default=yes]])], 
  [], [enable_threadsafe=yes])
-if test x"$enable_threadsafe" != "xno"; then
+if test x"$enable_threadsafe" == "xno"; then
+  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_THREADSAFE=0"
+else
  BUILD_CFLAGS="$BUILD_CFLAGS -D_REENTRANT=1 -DSQLITE_THREADSAFE=1"
  AC_SEARCH_LIBS(pthread_create, pthread)
  AC_SEARCH_LIBS(pthread_mutexattr_init, pthread)
@@ -109,14 +111,34 @@ AC_MSG_CHECKING([for whether to support dynamic extensions])
 AC_MSG_RESULT($enable_dynamic_extensions)
 #-----------------------------------------------------------------------

+#-----------------------------------------------------------------------
+#   --enable-math
+#
+AC_ARG_ENABLE(math, [AS_HELP_STRING(
+  [--enable-math], [SQL math functions [default=yes]])],
+  [], [enable_math=yes])
+AC_MSG_CHECKING([SQL math functions])
+if test x"$enable_math" = "xyes"; then
+  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_MATH_FUNCTIONS"
+  AC_MSG_RESULT([enabled])
+  AC_SEARCH_LIBS(ceil, m)
+else
+  AC_MSG_RESULT([disabled])
+fi
+#-----------------------------------------------------------------------
+
 #-----------------------------------------------------------------------
 #   --enable-fts4
 #
 AC_ARG_ENABLE(fts4, [AS_HELP_STRING(
  [--enable-fts4], [include fts4 support [default=yes]])], 
  [], [enable_fts4=yes])
+AC_MSG_CHECKING([FTS4 extension])
 if test x"$enable_fts4" = "xyes"; then
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_FTS4"
+  AC_MSG_RESULT([enabled])
+else
+  AC_MSG_RESULT([disabled])
 fi
 #-----------------------------------------------------------------------

@@ -126,8 +148,12 @@ fi
 AC_ARG_ENABLE(fts3, [AS_HELP_STRING(
  [--enable-fts3], [include fts3 support [default=no]])], 
  [], [])
+AC_MSG_CHECKING([FTS3 extension])
 if test x"$enable_fts3" = "xyes" -a x"$enable_fts4" = "xno"; then
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_FTS3"
+  AC_MSG_RESULT([enabled])
+else
+  AC_MSG_RESULT([disabled])
 fi
 #-----------------------------------------------------------------------

@@ -137,9 +163,13 @@ fi
 AC_ARG_ENABLE(fts5, [AS_HELP_STRING(
  [--enable-fts5], [include fts5 support [default=yes]])], 
  [], [enable_fts5=yes])
+AC_MSG_CHECKING([FTS5 extension])
 if test x"$enable_fts5" = "xyes"; then
+  AC_MSG_RESULT([enabled])
  AC_SEARCH_LIBS(log, m)
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_FTS5"
+else
+  AC_MSG_RESULT([disabled])
 fi
 #-----------------------------------------------------------------------

@@ -149,8 +179,12 @@ fi
 AC_ARG_ENABLE(json1, [AS_HELP_STRING(
  [--enable-json1], [include json1 support [default=yes]])], 
  [],[enable_json1=yes])
+AC_MSG_CHECKING([JSON functions])
 if test x"$enable_json1" = "xyes"; then
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_JSON1"
+  AC_MSG_RESULT([enabled])
+else
+  AC_MSG_RESULT([disabled])
 fi
 #-----------------------------------------------------------------------

@@ -160,8 +194,12 @@ fi
 AC_ARG_ENABLE(rtree, [AS_HELP_STRING(
  [--enable-rtree], [include rtree support [default=yes]])], 
  [], [enable_rtree=yes])
+AC_MSG_CHECKING([RTREE extension])
 if test x"$enable_rtree" = "xyes"; then
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_RTREE -DSQLITE_ENABLE_GEOPOLY"
+  AC_MSG_RESULT([enabled])
+else
+  AC_MSG_RESULT([disabled])
 fi
 #-----------------------------------------------------------------------

@@ -171,8 +209,12 @@ fi
 AC_ARG_ENABLE(session, [AS_HELP_STRING(
  [--enable-session], [enable the session extension [default=no]])], 
  [], [])
+AC_MSG_CHECKING([Session extension])
 if test x"$enable_session" = "xyes"; then
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_ENABLE_SESSION -DSQLITE_ENABLE_PREUPDATE_HOOK"
+  AC_MSG_RESULT([enabled])
+else
+  AC_MSG_RESULT([disabled])
 fi
 #-----------------------------------------------------------------------

@@ -182,9 +224,13 @@ fi
 AC_ARG_ENABLE(debug, [AS_HELP_STRING(
  [--enable-debug], [build with debugging features enabled [default=no]])], 
  [], [])
+AC_MSG_CHECKING([Build type])
 if test x"$enable_debug" = "xyes"; then
  BUILD_CFLAGS="$BUILD_CFLAGS -DSQLITE_DEBUG -DSQLITE_ENABLE_SELECTTRACE -DSQLITE_ENABLE_WHERETRACE"
  CFLAGS="-g -O0"
+  AC_MSG_RESULT([debug])
+else
+  AC_MSG_RESULT([release])
 fi
 #-----------------------------------------------------------------------

@@ -153,7 +153,7 @@ Please `cd` to its location first.
 #
 #-------------------------------------------------------------------------

-PROJECT = tclsqlite3
+PROJECT = sqlite3
 !include "rules.vc"

 # nmakehelp -V <file> <tag> will search the file for tag, skips until a
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for sqlite 3.32.0.
+# Generated by GNU Autoconf 2.69 for sqlite 3.35.4.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -726,8 +726,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='sqlite'
 PACKAGE_TARNAME='sqlite'
-PACKAGE_VERSION='3.32.0'
-PACKAGE_STRING='sqlite 3.32.0'
+PACKAGE_VERSION='3.35.4'
+PACKAGE_STRING='sqlite 3.35.4'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''

@@ -799,7 +799,6 @@ TEMP_STORE
 ALLOWRELEASE
 SQLITE_THREADSAFE
 BUILD_CC
-VERSION_NUMBER
 RELEASE
 VERSION
 program_prefix
@@ -904,9 +903,10 @@ with_readline_inc
 enable_debug
 enable_amalgamation
 enable_load_extension
+enable_math
+enable_all
 enable_memsys5
 enable_memsys3
-enable_all
 enable_fts3
 enable_fts4
 enable_fts5
@@ -1467,7 +1467,7 @@ if test "$ac_init_help" = "long"; then
  # Omit some internal or obsolete options to make the list less imposing.
  # This message is too long to be a string in the A/UX 3.1 sh.
  cat <<_ACEOF
-\`configure' configures sqlite 3.32.0 to adapt to many kinds of systems.
+\`configure' configures sqlite 3.35.4 to adapt to many kinds of systems.

 Usage: $0 [OPTION]... [VAR=VALUE]...

@@ -1532,7 +1532,7 @@ fi

 if test -n "$ac_init_help"; then
  case $ac_init_help in
-     short | recursive ) echo "Configuration of sqlite 3.32.0:";;
+     short | recursive ) echo "Configuration of sqlite 3.35.4:";;
   esac
  cat <<\_ACEOF

@@ -1558,9 +1558,10 @@ Optional Features:
                          separately
  --disable-load-extension
                          Disable loading of external extensions
+  --disable-math          Disable math functions
+  --enable-all            Enable FTS4, FTS5, Geopoly, JSON, RTree, Sessions
  --enable-memsys5        Enable MEMSYS5
  --enable-memsys3        Enable MEMSYS3
-  --enable-all            Enable FTS4, FTS5, Geopoly, JSON, RTree, Sessions
  --enable-fts3           Enable the FTS3 extension
  --enable-fts4           Enable the FTS4 extension
  --enable-fts5           Enable the FTS5 extension
@@ -1659,7 +1660,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
  cat <<\_ACEOF
-sqlite configure 3.32.0
+sqlite configure 3.35.4
 generated by GNU Autoconf 2.69

 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2078,7 +2079,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.

-It was created by sqlite $as_me 3.32.0, which was
+It was created by sqlite $as_me 3.35.4, which was
 generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@
@@ -3936,13 +3937,13 @@ if ${lt_cv_nm_interface+:} false; then :
 else
  lt_cv_nm_interface="BSD nm"
  echo "int some_variable = 0;" > conftest.$ac_ext
-  (eval echo "\"\$as_me:3939: $ac_compile\"" >&5)
+  (eval echo "\"\$as_me:3940: $ac_compile\"" >&5)
  (eval "$ac_compile" 2>conftest.err)
  cat conftest.err >&5
-  (eval echo "\"\$as_me:3942: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
+  (eval echo "\"\$as_me:3943: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
  (eval "$NM \"conftest.$ac_objext\"" 2>conftest.err > conftest.out)
  cat conftest.err >&5
-  (eval echo "\"\$as_me:3945: output\"" >&5)
+  (eval echo "\"\$as_me:3946: output\"" >&5)
  cat conftest.out >&5
  if $GREP 'External.*some_variable' conftest.out > /dev/null; then
    lt_cv_nm_interface="MS dumpbin"
@@ -5148,7 +5149,7 @@ ia64-*-hpux*)
  ;;
 *-*-irix6*)
  # Find out which ABI we are using.
-  echo '#line 5151 "configure"' > conftest.$ac_ext
+  echo '#line 5152 "configure"' > conftest.$ac_ext
  if { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_compile\""; } >&5
  (eval $ac_compile) 2>&5
  ac_status=$?
@@ -6673,11 +6674,11 @@ else
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:6676: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:6677: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:6680: \$? = $ac_status" >&5
+   echo "$as_me:6681: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings other than the usual output.
@@ -7012,11 +7013,11 @@ else
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7015: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7016: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:7019: \$? = $ac_status" >&5
+   echo "$as_me:7020: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s "$ac_outfile"; then
     # The compiler can only warn and ignore the option if not recognized
     # So say no if there are warnings other than the usual output.
@@ -7117,11 +7118,11 @@ else
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7120: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7121: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:7124: \$? = $ac_status" >&5
+   echo "$as_me:7125: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
@@ -7172,11 +7173,11 @@ else
   -e 's:.*FLAGS}\{0,1\} :&$lt_compiler_flag :; t' \
   -e 's: [^ ]*conftest\.: $lt_compiler_flag&:; t' \
   -e 's:$: $lt_compiler_flag:'`
-   (eval echo "\"\$as_me:7175: $lt_compile\"" >&5)
+   (eval echo "\"\$as_me:7176: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:7179: \$? = $ac_status" >&5
+   echo "$as_me:7180: \$? = $ac_status" >&5
   if (exit $ac_status) && test -s out/conftest2.$ac_objext
   then
     # The compiler can only warn and ignore the option if not recognized
@@ -9552,7 +9553,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<_LT_EOF
-#line 9555 "configure"
+#line 9556 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -9648,7 +9649,7 @@ else
  lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
  lt_status=$lt_dlunknown
  cat > conftest.$ac_ext <<_LT_EOF
-#line 9651 "configure"
+#line 9652 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -10365,8 +10366,10 @@ fi
 if test "x${TCLLIBDIR+set}" != "xset" ; then
  TCLLIBDIR='$(libdir)'
  for i in `echo 'puts stdout $auto_path' | ${TCLSH_CMD}` ; do
-    TCLLIBDIR=$i
-    break
+    if test -d $i ; then
+      TCLLIBDIR=$i
+      break
+    fi
  done
  TCLLIBDIR="${TCLLIBDIR}/sqlite3"
 fi
@@ -10388,12 +10391,6 @@ RELEASE=`cat $srcdir/VERSION`
 { $as_echo "$as_me:${as_lineno-$LINENO}: Release set to $RELEASE" >&5
 $as_echo "$as_me: Release set to $RELEASE" >&6;}

-VERSION_NUMBER=`cat $srcdir/VERSION \
-                           | sed 's/[^0-9]/ /g' \
-                | awk '{printf "%d%03d%03d",$1,$2,$3}'`
-{ $as_echo "$as_me:${as_lineno-$LINENO}: Version number set to $VERSION_NUMBER" >&5
-$as_echo "$as_me: Version number set to $VERSION_NUMBER" >&6;}
-

 #########
 # Locate a compiler for the build machine.  This compiler should
@@ -11254,10 +11251,16 @@ if test "${enable_debug+set}" = set; then :
  enableval=$enable_debug;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking build type" >&5
+$as_echo_n "checking build type... " >&6; }
 if test "${enable_debug}" = "yes" ; then
  TARGET_DEBUG="-DSQLITE_DEBUG=1 -DSQLITE_ENABLE_SELECTTRACE -DSQLITE_ENABLE_WHERETRACE -O0"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: debug" >&5
+$as_echo "debug" >&6; }
 else
  TARGET_DEBUG="-DNDEBUG"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: release" >&5
+$as_echo "release" >&6; }
 fi


@@ -11268,7 +11271,7 @@ if test "${enable_amalgamation+set}" = set; then :
  enableval=$enable_amalgamation;
 fi

-if test "${enable_amalgamation}" == "no" ; then
+if test "${enable_amalgamation}" = "no" ; then
  USE_AMALGAMATION=0
 fi

@@ -11418,6 +11421,91 @@ else
  OPT_FEATURE_FLAGS="-DSQLITE_OMIT_LOAD_EXTENSION=1"
 fi

+##########
+# Do we want to support math functions
+#
+# Check whether --enable-math was given.
+if test "${enable_math+set}" = set; then :
+  enableval=$enable_math;
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support math functions" >&5
+$as_echo_n "checking whether to support math functions... " >&6; }
+if test "$enable_math" = "no"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_MATH_FUNCTIONS"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing ceil" >&5
+$as_echo_n "checking for library containing ceil... " >&6; }
+if ${ac_cv_search_ceil+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char ceil ();
+int
+main ()
+{
+return ceil ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' m; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_search_ceil=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if ${ac_cv_search_ceil+:} false; then :
+  break
+fi
+done
+if ${ac_cv_search_ceil+:} false; then :
+
+else
+  ac_cv_search_ceil=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_ceil" >&5
+$as_echo "$ac_cv_search_ceil" >&6; }
+ac_res=$ac_cv_search_ceil
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+fi
+
+
+########
+# The --enable-all argument is short-hand to enable
+# multiple extensions.
+# Check whether --enable-all was given.
+if test "${enable_all+set}" = set; then :
+  enableval=$enable_all;
+fi
+
+
 ##########
 # Do we want to support memsys3 and/or memsys5
 #
@@ -11452,15 +11540,6 @@ else
 $as_echo "no" >&6; }
 fi

-########
-# The --enable-extensions argument is short-hand to enable
-# multiple extensions.
-# Check whether --enable-all was given.
-if test "${enable_all+set}" = set; then :
-  enableval=$enable_all;
-fi
-
-
 #########
 # See whether we should enable Full Text Search extensions
 # Check whether --enable-fts3 was given.
@@ -11468,15 +11547,26 @@ if test "${enable_fts3+set}" = set; then :
  enableval=$enable_fts3;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support FTS3" >&5
+$as_echo_n "checking whether to support FTS3... " >&6; }
 if test "${enable_fts3}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_FTS3"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi
 # Check whether --enable-fts4 was given.
 if test "${enable_fts4+set}" = set; then :
  enableval=$enable_fts4;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support FTS4" >&5
+$as_echo_n "checking whether to support FTS4... " >&6; }
 if test "${enable_fts4}" = "yes" -o "${enable_all}" = "yes" ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_FTS4"
  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing log" >&5
 $as_echo_n "checking for library containing log... " >&6; }
@@ -11534,13 +11624,20 @@ if test "$ac_res" != no; then :

 fi

+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi
 # Check whether --enable-fts5 was given.
 if test "${enable_fts5+set}" = set; then :
  enableval=$enable_fts5;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support FTS5" >&5
+$as_echo_n "checking whether to support FTS5... " >&6; }
 if test "${enable_fts5}" = "yes" -o "${enable_all}" = "yes" ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_FTS5"
  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing log" >&5
 $as_echo_n "checking for library containing log... " >&6; }
@@ -11598,6 +11695,9 @@ if test "$ac_res" != no; then :

 fi

+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

 #########
@@ -11607,8 +11707,15 @@ if test "${enable_json1+set}" = set; then :
  enableval=$enable_json1;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support JSON" >&5
+$as_echo_n "checking whether to support JSON... " >&6; }
 if test "${enable_json1}" = "yes" -o "${enable_all}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_JSON1"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

 #########
@@ -11619,8 +11726,15 @@ if test "${enable_update_limit+set}" = set; then :
  enableval=$enable_update_limit;
 fi

-if test "${enable_udlimit}" = "yes" ; then
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support LIMIT on UPDATE and DELETE statements" >&5
+$as_echo_n "checking whether to support LIMIT on UPDATE and DELETE statements... " >&6; }
+if test "${enable_update_limit}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_UPDATE_DELETE_LIMIT"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

 #########
@@ -11632,9 +11746,16 @@ else
  enable_geopoly=no
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support GEOPOLY" >&5
+$as_echo_n "checking whether to support GEOPOLY... " >&6; }
 if test "${enable_geopoly}" = "yes" -o "${enable_all}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_GEOPOLY"
  enable_rtree=yes
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

 #########
@@ -11644,8 +11765,15 @@ if test "${enable_rtree+set}" = set; then :
  enableval=$enable_rtree;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support RTREE" >&5
+$as_echo_n "checking whether to support RTREE... " >&6; }
 if test "${enable_rtree}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_RTREE"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

 #########
@@ -11655,9 +11783,16 @@ if test "${enable_session+set}" = set; then :
  enableval=$enable_session;
 fi

+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to support SESSION" >&5
+$as_echo_n "checking whether to support SESSION... " >&6; }
 if test "${enable_session}" = "yes" -o "${enable_all}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_SESSION"
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_PREUPDATE_HOOK"
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
 fi

 #########
@@ -12243,7 +12378,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by sqlite $as_me 3.32.0, which was
+This file was extended by sqlite $as_me 3.35.4, which was
 generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
@@ -12309,7 +12444,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-sqlite config.status 3.32.0
+sqlite config.status 3.35.4
 configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

@@ -134,8 +134,10 @@ AC_ARG_VAR([TCLLIBDIR], [Where to install tcl plugin])
 if test "x${TCLLIBDIR+set}" != "xset" ; then
  TCLLIBDIR='$(libdir)'
  for i in `echo 'puts stdout $auto_path' | ${TCLSH_CMD}` ; do
-    TCLLIBDIR=$i
-    break
+    if test -d $i ; then
+      TCLLIBDIR=$i
+      break
+    fi
  done
  TCLLIBDIR="${TCLLIBDIR}/sqlite3"
 fi
@@ -155,11 +157,6 @@ AC_SUBST(VERSION)
 RELEASE=`cat $srcdir/VERSION`
 AC_MSG_NOTICE(Release set to $RELEASE)
 AC_SUBST(RELEASE)
-VERSION_NUMBER=[`cat $srcdir/VERSION \
-                           | sed 's/[^0-9]/ /g' \
-                | awk '{printf "%d%03d%03d",$1,$2,$3}'`]
-AC_MSG_NOTICE(Version number set to $VERSION_NUMBER)
-AC_SUBST(VERSION_NUMBER)

 #########
 # Locate a compiler for the build machine.  This compiler should
@@ -558,10 +555,13 @@ AC_SEARCH_LIBS(fdatasync, [rt])
 #########
 # check for debug enabled
 AC_ARG_ENABLE(debug, AC_HELP_STRING([--enable-debug],[enable debugging & verbose explain]))
+AC_MSG_CHECKING([build type])
 if test "${enable_debug}" = "yes" ; then
  TARGET_DEBUG="-DSQLITE_DEBUG=1 -DSQLITE_ENABLE_SELECTTRACE -DSQLITE_ENABLE_WHERETRACE -O0"
+  AC_MSG_RESULT([debug])
 else
  TARGET_DEBUG="-DNDEBUG"
+  AC_MSG_RESULT([release])
 fi
 AC_SUBST(TARGET_DEBUG)

@@ -569,7 +569,7 @@ AC_SUBST(TARGET_DEBUG)
 # See whether we should use the amalgamation to build
 AC_ARG_ENABLE(amalgamation, AC_HELP_STRING([--disable-amalgamation],
      [Disable the amalgamation and instead build all files separately]))
-if test "${enable_amalgamation}" == "no" ; then
+if test "${enable_amalgamation}" = "no" ; then
  USE_AMALGAMATION=0
 fi
 AC_SUBST(USE_AMALGAMATION)
@@ -591,6 +591,27 @@ else
  OPT_FEATURE_FLAGS="-DSQLITE_OMIT_LOAD_EXTENSION=1"
 fi

+##########
+# Do we want to support math functions
+#
+AC_ARG_ENABLE(math, 
+AC_HELP_STRING([--disable-math],[Disable math functions]))
+AC_MSG_CHECKING([whether to support math functions])
+if test "$enable_math" = "no"; then
+  AC_MSG_RESULT([no])
+else
+  AC_MSG_RESULT([yes])
+  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_MATH_FUNCTIONS"
+  AC_SEARCH_LIBS(ceil, m)
+fi
+
+
+########
+# The --enable-all argument is short-hand to enable
+# multiple extensions.
+AC_ARG_ENABLE(all, AC_HELP_STRING([--enable-all],
+      [Enable FTS4, FTS5, Geopoly, JSON, RTree, Sessions]))
+
 ##########
 # Do we want to support memsys3 and/or memsys5
 #
@@ -613,37 +634,47 @@ else
  AC_MSG_RESULT([no])
 fi

-########
-# The --enable-extensions argument is short-hand to enable
-# multiple extensions.
-AC_ARG_ENABLE(all, AC_HELP_STRING([--enable-all],
-      [Enable FTS4, FTS5, Geopoly, JSON, RTree, Sessions]))
-
 #########
 # See whether we should enable Full Text Search extensions
 AC_ARG_ENABLE(fts3, AC_HELP_STRING([--enable-fts3],
      [Enable the FTS3 extension]))
+AC_MSG_CHECKING([whether to support FTS3])
 if test "${enable_fts3}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_FTS3"
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
 fi
 AC_ARG_ENABLE(fts4, AC_HELP_STRING([--enable-fts4],
      [Enable the FTS4 extension]))
+AC_MSG_CHECKING([whether to support FTS4])
 if test "${enable_fts4}" = "yes" -o "${enable_all}" = "yes" ; then
+  AC_MSG_RESULT([yes])
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_FTS4"
  AC_SEARCH_LIBS([log],[m])
+else
+  AC_MSG_RESULT([no])
 fi
 AC_ARG_ENABLE(fts5, AC_HELP_STRING([--enable-fts5],
      [Enable the FTS5 extension]))
+AC_MSG_CHECKING([whether to support FTS5])
 if test "${enable_fts5}" = "yes" -o "${enable_all}" = "yes" ; then
+  AC_MSG_RESULT([yes])
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_FTS5"
  AC_SEARCH_LIBS([log],[m])
+else
+  AC_MSG_RESULT([no])
 fi

 #########
 # See whether we should enable JSON1
 AC_ARG_ENABLE(json1, AC_HELP_STRING([--enable-json1],[Enable the JSON1 extension]))
+AC_MSG_CHECKING([whether to support JSON])
 if test "${enable_json1}" = "yes" -o "${enable_all}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_JSON1"
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
 fi

 #########
@@ -651,8 +682,12 @@ fi
 # statements.
 AC_ARG_ENABLE(update-limit, AC_HELP_STRING([--enable-update-limit],
      [Enable the UPDATE/DELETE LIMIT clause]))
-if test "${enable_udlimit}" = "yes" ; then
+AC_MSG_CHECKING([whether to support LIMIT on UPDATE and DELETE statements])
+if test "${enable_update_limit}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_UPDATE_DELETE_LIMIT"
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
 fi

 #########
@@ -660,26 +695,38 @@ fi
 AC_ARG_ENABLE(geopoly, AC_HELP_STRING([--enable-geopoly],
      [Enable the GEOPOLY extension]),
      [enable_geopoly=yes],[enable_geopoly=no])
+AC_MSG_CHECKING([whether to support GEOPOLY])
 if test "${enable_geopoly}" = "yes" -o "${enable_all}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_GEOPOLY"
  enable_rtree=yes
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
 fi

 #########
 # See whether we should enable RTREE
 AC_ARG_ENABLE(rtree, AC_HELP_STRING([--enable-rtree],
      [Enable the RTREE extension]))
+AC_MSG_CHECKING([whether to support RTREE])
 if test "${enable_rtree}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_RTREE"
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
 fi

 #########
 # See whether we should enable the SESSION extension
 AC_ARG_ENABLE(session, AC_HELP_STRING([--enable-session],
      [Enable the SESSION extension]))
+AC_MSG_CHECKING([whether to support SESSION])
 if test "${enable_session}" = "yes" -o "${enable_all}" = "yes" ; then
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_SESSION"
  OPT_FEATURE_FLAGS="${OPT_FEATURE_FLAGS} -DSQLITE_ENABLE_PREUPDATE_HOOK"
+  AC_MSG_RESULT([yes])
+else
+  AC_MSG_RESULT([no])
 fi

 #########
@@ -0,0 +1,49 @@
+
+20-11-2020
+
+# Memory Allocation In vdbesort.c
+
+Memory allocation is slightly different depending on:
+
+  * whether or not SQLITE_CONFIG_SMALL_MALLOC is set, and
+  * whether or not worker threads are enabled.
+
+## SQLITE_CONFIG_SMALL_MALLOC=0
+
+Assuming SQLITE_CONFIG_SMALL_MALLOC is not set, keys passed to the sorter are
+added to an in-memory buffer. This buffer is grown using sqlite3Realloc() as
+required it reaches the size configured for the main pager cache using "PRAGMA
+cache_size". i.e. if the user has executed "PRAGMA main.cache_size = -2048",
+then this buffer is allowed to grow up to 2MB in size.
+
+Once the buffer has grown to its threshold, keys are sorted and written to
+a temp file. If worker threads are not enabled, this is the only significant
+allocation the sorter module makes. After keys are sorted and flushed out to
+the temp file, the buffer is reused to accumulate the next batch of keys.
+
+If worker threads are available, then the buffer is passed to a worker thread
+to sort and flush once it is full, and a new buffer allocated to allow the
+main thread to continue to accumulate keys. Buffers are reused once they
+have been flushed, so in this case at most (nWorker+1) buffers are allocated
+and used, where nWorker is the number of configured worker threads.
+
+There are no other significant users of heap memory in the sorter module. 
+Once sorted buffers of keys have been flushed to disk, they are read back
+either by mapping the file (via sqlite3_file.xFetch()) or else read back
+in one page at a time.
+
+All buffers are allocated by the main thread. A sorter object is associated
+with a single database connection, to which it holds a pointer.
+
+## SQLITE_CONFIG_SMALL_MALLOC=1
+
+This case is similar to the above, except that instead of accumulating
+multiple keys in a single large buffer, sqlite3VdbeSorterWrite() stores
+keys in a regular heap-memory linked list (one allocation per element).
+List elements are freed as they are flushed to disk, either by the main
+thread or by a worker thread.
+
+Each time a key is added the sorter (and an allocation made),
+sqlite3HeapNearlyFull() is called. If it returns true, the current
+list of keys is flushed to a temporary file, even if it has not yet
+reached the size threshold.
@@ -0,0 +1,88 @@
+# Wal-Mode Blocking Locks
+
+On some Unix-like systems, SQLite may be configured to use POSIX blocking locks
+by:
+
+  * building the library with SQLITE\_ENABLE\_SETLK\_TIMEOUT defined, and 
+  * configuring a timeout in ms using the sqlite3\_busy\_timeout() API.
+
+Blocking locks may be advantageous as (a) waiting database clients do not
+need to continuously poll the database lock, and (b) using blocking locks
+facilitates transfer of OS priority between processes when a high priority
+process is blocked by a lower priority one.
+
+Only read/write clients use blocking locks. Clients that have read-only access
+to the \*-shm file nevery use blocking locks.
+
+Threads or processes that access a single database at a time never deadlock as
+a result of blocking database locks. But it is of course possible for threads
+that lock multiple databases simultaneously to do so. In most cases the OS will
+detect the deadlock and return an error.
+
+## Wal Recovery
+
+Wal database "recovery" is a process required when the number of connected
+database clients changes from zero to one. In this case, a client is 
+considered to connect to the database when it first reads data from it.
+Before recovery commences, an exclusive WRITER lock is taken. 
+
+Without blocking locks, if two clients attempt recovery simultaneously, one
+fails to obtain the WRITER lock and either invokes the busy-handler callback or
+returns SQLITE\_BUSY to the user. With blocking locks configured, the second
+client blocks on the WRITER lock.
+
+## Database Readers
+
+Usually, read-only are not blocked by any other database clients, so they 
+have no need of blocking locks.
+
+If a read-only transaction is being opened on a snapshot, the CHECKPOINTER
+lock is required briefly as part of opening the transaction (to check that a
+checkpointer is not currently overwriting the snapshot being opened). A
+blocking lock is used to obtain the CHECKPOINTER lock in this case. A snapshot
+opener may therefore block on and transfer priority to a checkpointer in some
+cases.
+
+## Database Writers
+
+A database writer must obtain the exclusive WRITER lock. It uses a blocking
+lock to do so if any of the following are true:
+
+  * the transaction is an implicit one consisting of a single DML or DDL
+    statement, or
+  * the transaction is opened using BEGIN IMMEDIATE or BEGIN EXCLUSIVE, or
+  * the first SQL statement executed following the BEGIN command is a DML or
+    DDL statement (not a read-only statement like a SELECT).
+
+In other words, in all cases except when an open read-transaction is upgraded
+to a write-transaction. In that case a non-blocking lock is used.
+
+## Database Checkpointers
+
+Database checkpointers takes the following locks, in order:
+
+  * The exclusive CHECKPOINTER lock.
+  * The exclusive WRITER lock (FULL, RESTART and TRUNCATE only).
+  * Exclusive lock on read-mark slots 1-N. These are immediately released after being taken.
+  * Exclusive lock on read-mark 0.
+  * Exclusive lock on read-mark slots 1-N again. These are immediately released
+    after being taken (RESTART and TRUNCATE only).
+
+All of the above use blocking locks.
+
+## Summary
+
+With blocking locks configured, the only cases in which clients should see an
+SQLITE\_BUSY error are:
+
+  * if the OS does not grant a blocking lock before the configured timeout
+    expires, and
+  * when an open read-transaction is upgraded to a write-transaction.
+
+In all other cases the blocking locks implementation should prevent clients
+from having to handle SQLITE\_BUSY errors and facilitate appropriate transfer
+of priorities between competing clients.
+
+Clients that lock multiple databases simultaneously must be wary of deadlock.
+
+
@@ -1704,4 +1704,3 @@ int sqlite3async_control(int op, ...){
 }

 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ASYNCIO) */
-
@@ -220,4 +220,3 @@ int sqlite3async_control(int op, ...);
 }  /* End of the 'extern "C"' block */
 #endif
 #endif        /* ifndef __SQLITEASYNC_H_ */
-
@@ -28,6 +28,7 @@ if {[info commands sqlite3_expert_new]==""} {
  return
 }

+
 set CLI [test_binary_name sqlite3]
 set CMD [test_binary_name sqlite3_expert]

@@ -326,6 +327,70 @@ do_setup_rec_test $tn.16 {
  SCAN TABLE t1
 }

+do_setup_rec_test $tn.17.1 {
+  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+  SELECT * FROM example WHERE a=?
+} {
+  (no new indexes)
+  SEARCH TABLE example USING INDEX sqlite_autoindex_example_1 (A=?)
+}
+do_setup_rec_test $tn.17.2 {
+  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+  SELECT * FROM example WHERE b=?
+} {
+  CREATE INDEX example_idx_00000042 ON example(B);
+  SEARCH TABLE example USING INDEX example_idx_00000042 (B=?)
+}
+do_setup_rec_test $tn.17.3 {
+  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+  SELECT * FROM example WHERE a=? AND b=?
+} {
+  (no new indexes)
+  SEARCH TABLE example USING INDEX sqlite_autoindex_example_1 (A=? AND B=?)
+}
+do_setup_rec_test $tn.17.4 {
+  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+  SELECT * FROM example WHERE a=? AND b>?
+} {
+  (no new indexes)
+  SEARCH TABLE example USING INDEX sqlite_autoindex_example_1 (A=? AND B>?)
+}
+do_setup_rec_test $tn.17.5 {
+  CREATE TABLE example (A INTEGER, B INTEGER, C INTEGER, PRIMARY KEY (A,B));
+} {
+  SELECT * FROM example WHERE a>? AND b=?
+} {
+  CREATE INDEX example_idx_0000cb3f ON example(B, A);
+  SEARCH TABLE example USING INDEX example_idx_0000cb3f (B=? AND A>?)
+}
+
+do_setup_rec_test $tn.18.0 {
+  CREATE TABLE SomeObject (
+     a INTEGER PRIMARY KEY,
+     x TEXT GENERATED ALWAYS AS(HEX(a)) VIRTUAL
+  );
+} {
+  SELECT x FROM SomeObject;
+} {
+  (no new indexes)
+  SCAN TABLE SomeObject
+}
+do_setup_rec_test $tn.18.1 {
+  CREATE TABLE SomeObject (
+     a INTEGER PRIMARY KEY,
+     x TEXT GENERATED ALWAYS AS(HEX(a)) VIRTUAL
+  );
+} {
+  SELECT * FROM SomeObject WHERE x=?;
+} {
+  CREATE INDEX SomeObject_idx_00000078 ON SomeObject(x);
+  SEARCH TABLE SomeObject USING COVERING INDEX SomeObject_idx_00000078 (x=?)
+}
+
 }

 proc do_candidates_test {tn sql res} {
@@ -389,5 +454,5 @@ do_execsql_test 5.3 {
  t2 t2_idx_0001295b {100 20 5}
 }

-
 finish_test
+
@@ -685,8 +685,9 @@ static int idxGetTableInfo(
  IdxTable *pNew = 0;
  int rc, rc2;
  char *pCsr = 0;
+  int nPk = 0;

-  rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_info=%Q", zTab);
+  rc = idxPrintfPrepareStmt(db, &p1, pzErrmsg, "PRAGMA table_xinfo=%Q", zTab);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    nByte += 1 + STRLEN(zCol);
@@ -695,6 +696,7 @@ static int idxGetTableInfo(
    );
    nByte += 1 + STRLEN(zCol);
    nCol++;
+    nPk += (sqlite3_column_int(p1, 5)>0);
  }
  rc2 = sqlite3_reset(p1);
  if( rc==SQLITE_OK ) rc = rc2;
@@ -714,7 +716,7 @@ static int idxGetTableInfo(
    const char *zCol = (const char*)sqlite3_column_text(p1, 1);
    int nCopy = STRLEN(zCol) + 1;
    pNew->aCol[nCol].zName = pCsr;
-    pNew->aCol[nCol].iPk = sqlite3_column_int(p1, 5);
+    pNew->aCol[nCol].iPk = (sqlite3_column_int(p1, 5)==1 && nPk==1);
    memcpy(pCsr, zCol, nCopy);
    pCsr += nCopy;

@@ -1128,14 +1130,19 @@ int idxFindIndexes(
      /* int iParent = sqlite3_column_int(pExplain, 1); */
      /* int iNotUsed = sqlite3_column_int(pExplain, 2); */
      const char *zDetail = (const char*)sqlite3_column_text(pExplain, 3);
-      int nDetail = STRLEN(zDetail);
+      int nDetail;
      int i;

+      if( !zDetail ) continue;
+      nDetail = STRLEN(zDetail);
+
      for(i=0; i<nDetail; i++){
        const char *zIdx = 0;
-        if( memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
+        if( i+13<nDetail && memcmp(&zDetail[i], " USING INDEX ", 13)==0 ){
          zIdx = &zDetail[i+13];
-        }else if( memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 ){
+        }else if( i+22<nDetail 
+            && memcmp(&zDetail[i], " USING COVERING INDEX ", 22)==0 
+        ){
          zIdx = &zDetail[i+22];
        }
        if( zIdx ){
@@ -1218,7 +1225,7 @@ static int idxProcessOneTrigger(
  IdxTable *pTab = pWrite->pTab;
  const char *zTab = pTab->zName;
  const char *zSql = 
-    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_master "
+    "SELECT 'CREATE TEMP' || substr(sql, 7) FROM sqlite_schema "
    "WHERE tbl_name = %Q AND type IN ('table', 'trigger') "
    "ORDER BY type;";
  sqlite3_stmt *pSelect = 0;
@@ -1318,12 +1325,12 @@ static int idxCreateVtabSchema(sqlite3expert *p, char **pzErrmsg){
  **   2) Create the equivalent virtual table in dbv.
  */
  rc = idxPrepareStmt(p->db, &pSchema, pzErrmsg,
-      "SELECT type, name, sql, 1 FROM sqlite_master "
+      "SELECT type, name, sql, 1 FROM sqlite_schema "
      "WHERE type IN ('table','view') AND name NOT LIKE 'sqlite_%%' "
      " UNION ALL "
-      "SELECT type, name, sql, 2 FROM sqlite_master "
+      "SELECT type, name, sql, 2 FROM sqlite_schema "
      "WHERE type = 'trigger'"
-      "  AND tbl_name IN(SELECT name FROM sqlite_master WHERE type = 'view') "
+      "  AND tbl_name IN(SELECT name FROM sqlite_schema WHERE type = 'view') "
      "ORDER BY 4, 1"
  );
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSchema) ){
@@ -1493,7 +1500,7 @@ static int idxLargestIndex(sqlite3 *db, int *pnMax, char **pzErr){
  int rc = SQLITE_OK;
  const char *zMax = 
    "SELECT max(i.seqno) FROM "
-    "  sqlite_master AS s, "
+    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l, "
    "  pragma_index_info(l.name) AS i "
    "WHERE s.type = 'table'";
@@ -1646,7 +1653,7 @@ static int idxPopulateStat1(sqlite3expert *p, char **pzErr){

  const char *zAllIndex =
    "SELECT s.rowid, s.name, l.name FROM "
-    "  sqlite_master AS s, "
+    "  sqlite_schema AS s, "
    "  pragma_index_list(s.name) AS l "
    "WHERE s.type = 'table'";
  const char *zIndexXInfo = 
@@ -1714,13 +1721,15 @@ static int idxPopulateStat1(sqlite3expert *p, char **pzErr){
  idxFinalize(&rc, pIndexXInfo);
  idxFinalize(&rc, pWrite);

-  for(i=0; i<pCtx->nSlot; i++){
-    sqlite3_free(pCtx->aSlot[i].z);
+  if( pCtx ){
+    for(i=0; i<pCtx->nSlot; i++){
+      sqlite3_free(pCtx->aSlot[i].z);
+    }
+    sqlite3_free(pCtx);
  }
-  sqlite3_free(pCtx);

  if( rc==SQLITE_OK ){
-    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_master", 0, 0, 0);
+    rc = sqlite3_exec(p->dbm, "ANALYZE sqlite_schema", 0, 0, 0);
  }

  sqlite3_exec(p->db, "DROP TABLE IF EXISTS temp."UNIQUE_TABLE_NAME,0,0,0);
@@ -1759,7 +1768,7 @@ sqlite3expert *sqlite3_expert_new(sqlite3 *db, char **pzErrmsg){
  if( rc==SQLITE_OK ){
    sqlite3_stmt *pSql;
    rc = idxPrintfPrepareStmt(pNew->db, &pSql, pzErrmsg, 
-        "SELECT sql FROM sqlite_master WHERE name NOT LIKE 'sqlite_%%'"
+        "SELECT sql FROM sqlite_schema WHERE name NOT LIKE 'sqlite_%%'"
        " AND sql NOT LIKE 'CREATE VIRTUAL %%'"
    );
    while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSql) ){
@@ -1950,4 +1959,4 @@ void sqlite3_expert_destroy(sqlite3expert *p){
  }
 }

-#endif /* ifndef SQLITE_OMIT_VIRTUAL_TABLE */
+#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */
@@ -174,5 +174,3 @@ EXTERNAL CONTENT FTS4 TABLES
  only be useful if the full-text index has somehow become corrupt. It is an
  error to attempt to rebuild the full-text index maintained by a contentless
  FTS4 table.
-
-
@@ -2068,7 +2068,7 @@ static void fts3PutDeltaVarint(
  sqlite3_int64 *piPrev,          /* IN/OUT: Previous value written to list */
  sqlite3_int64 iVal              /* Write this value to the list */
 ){
-  assert( iVal-*piPrev > 0 || (*piPrev==0 && iVal==0) );
+  assert_fts3_nc( iVal-*piPrev > 0 || (*piPrev==0 && iVal==0) );
  *pp += sqlite3Fts3PutVarint(*pp, iVal-*piPrev);
  *piPrev = iVal;
 }
@@ -2185,7 +2185,9 @@ static void fts3ReadNextPos(
  sqlite3_int64 *pi             /* IN/OUT: Value read from position-list */
 ){
  if( (**pp)&0xFE ){
-    fts3GetDeltaVarint(pp, pi);
+    int iVal;
+    *pp += fts3GetVarint32((*pp), &iVal);
+    *pi += iVal;
    *pi -= 2;
  }else{
    *pi = POSITION_LIST_END;
@@ -2265,6 +2267,9 @@ static int fts3PoslistMerge(
      */
      fts3GetDeltaVarint(&p1, &i1);
      fts3GetDeltaVarint(&p2, &i2);
+      if( i1<2 || i2<2 ){
+        break;
+      }
      do {
        fts3PutDeltaVarint(&p, &iPrev, (i1<i2) ? i1 : i2); 
        iPrev -= 2;
@@ -2333,7 +2338,7 @@ static int fts3PoslistPhraseMerge(
  /* Never set both isSaveLeft and isExact for the same invocation. */
  assert( isSaveLeft==0 || isExact==0 );

-  assert( p!=0 && *p1!=0 && *p2!=0 );
+  assert_fts3_nc( p!=0 && *p1!=0 && *p2!=0 );
  if( *p1==POS_COLUMN ){ 
    p1++;
    p1 += fts3GetVarint32(p1, &iCol1);
@@ -3474,7 +3479,7 @@ static int fts3ColumnMethod(
        break;
      }else{
        iCol = p->nColumn;
-        /* fall-through */
+        /* no break */ deliberate_fall_through
      }

    default:
@@ -3717,9 +3722,13 @@ static void fts3SnippetFunc(

  switch( nVal ){
    case 6: nToken = sqlite3_value_int(apVal[5]);
+            /* no break */ deliberate_fall_through
    case 5: iCol = sqlite3_value_int(apVal[4]);
+            /* no break */ deliberate_fall_through
    case 4: zEllipsis = (const char*)sqlite3_value_text(apVal[3]);
+            /* no break */ deliberate_fall_through
    case 3: zEnd = (const char*)sqlite3_value_text(apVal[2]);
+            /* no break */ deliberate_fall_through
    case 2: zStart = (const char*)sqlite3_value_text(apVal[1]);
  }
  if( !zEllipsis || !zEnd || !zStart ){
@@ -4518,7 +4527,7 @@ void sqlite3Fts3DoclistNext(

  assert( nDoclist>0 );
  assert( *pbEof==0 );
-  assert( p || *piDocid==0 );
+  assert_fts3_nc( p || *piDocid==0 );
  assert( !p || (p>=aDoclist && p<=&aDoclist[nDoclist]) );

  if( p==0 ){
@@ -5168,7 +5177,7 @@ static void fts3EvalInvalidatePoslist(Fts3Phrase *pPhrase){
 **
 ** Parameter nNear is passed the NEAR distance of the expression (5 in
 ** the example above). When this function is called, *paPoslist points to
-** the position list, and *pnToken is the number of phrase tokens in, the
+** the position list, and *pnToken is the number of phrase tokens in the
 ** phrase on the other side of the NEAR operator to pPhrase. For example,
 ** if pPhrase refers to the "def ghi" phrase, then *paPoslist points to
 ** the position list associated with phrase "abc".
@@ -5203,10 +5212,12 @@ static int fts3EvalNearTrim(
  );
  if( res ){
    nNew = (int)(pOut - pPhrase->doclist.pList) - 1;
-    assert( pPhrase->doclist.pList[nNew]=='\0' );
-    assert( nNew<=pPhrase->doclist.nList && nNew>0 );
-    memset(&pPhrase->doclist.pList[nNew], 0, pPhrase->doclist.nList - nNew);
-    pPhrase->doclist.nList = nNew;
+    assert_fts3_nc( nNew<=pPhrase->doclist.nList && nNew>0 );
+    if( nNew>=0 && nNew<=pPhrase->doclist.nList ){
+      assert( pPhrase->doclist.pList[nNew]=='\0' );
+      memset(&pPhrase->doclist.pList[nNew], 0, pPhrase->doclist.nList - nNew);
+      pPhrase->doclist.nList = nNew;
+    }
    *paPoslist = pPhrase->doclist.pList;
    *pnToken = pPhrase->nToken;
  }
@@ -5315,6 +5326,7 @@ static void fts3EvalNextRow(
                fts3EvalNextRow(pCsr, pLeft, pRc);
              }
            }
+            pRight->bEof = pLeft->bEof = 1;
          }
        }
        break;
@@ -5557,7 +5569,10 @@ static int fts3EvalTestExpr(
        }else
 #endif
        {
-          bHit = (pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId);
+          bHit = ( 
+              pExpr->bEof==0 && pExpr->iDocid==pCsr->iPrevId
+           && pExpr->pPhrase->doclist.nList>0
+          );
        }
        break;
      }
@@ -5820,7 +5835,8 @@ static int fts3EvalGatherStats(
      fts3EvalRestart(pCsr, pRoot, &rc);
      do {
        fts3EvalNextRow(pCsr, pRoot, &rc);
-        assert( pRoot->bEof==0 );
+        assert_fts3_nc( pRoot->bEof==0 );
+        if( pRoot->bEof ) rc = FTS_CORRUPT_VTAB;
      }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );
    }
  }
@@ -199,6 +199,8 @@ typedef sqlite3_int64 i64;        /* 8-byte signed integer */
 #define LARGEST_INT64  (0xffffffff|(((i64)0x7fffffff)<<32))
 #define SMALLEST_INT64 (((i64)-1) - LARGEST_INT64)

+#define deliberate_fall_through
+
 #endif /* SQLITE_AMALGAMATION */

 #ifdef SQLITE_DEBUG
@@ -493,6 +493,11 @@ static int getNextNode(
    if( *zInput=='(' ){
      int nConsumed = 0;
      pParse->nNest++;
+#if !defined(SQLITE_MAX_EXPR_DEPTH)
+      if( pParse->nNest>1000 ) return SQLITE_ERROR;
+#elif SQLITE_MAX_EXPR_DEPTH>0
+      if( pParse->nNest>SQLITE_MAX_EXPR_DEPTH ) return SQLITE_ERROR;
+#endif
      rc = fts3ExprParse(pParse, zInput+1, nInput-1, ppExpr, &nConsumed);
      *pnConsumed = (int)(zInput - z) + 1 + nConsumed;
      return rc;
@@ -876,7 +876,7 @@ static int fts3ExprLHits(
    iStart = pExpr->iPhrase * ((p->nCol + 31) / 32);
  }

-  while( 1 ){
+  if( pIter ) while( 1 ){
    int nHit = fts3ColumnlistCount(&pIter);
    if( (pPhrase->iColumn>=pTab->nColumn || pPhrase->iColumn==iCol) ){
      if( p->flag==FTS3_MATCHINFO_LHITS ){
@@ -188,7 +188,8 @@ static int fts3tokConnectMethod(

  assert( (rc==SQLITE_OK)==(pMod!=0) );
  if( rc==SQLITE_OK ){
-    const char * const *azArg = (const char * const *)&azDequote[1];
+    const char * const *azArg = 0;
+    if( nDequote>1 ) azArg = (const char * const *)&azDequote[1];
    rc = pMod->xCreate((nDequote>1 ? nDequote-1 : 0), azArg, &pTok);
  }

@@ -285,6 +285,7 @@ static int unicodeOpen(
  pCsr->aInput = (const unsigned char *)aInput;
  if( aInput==0 ){
    pCsr->nInput = 0;
+    pCsr->aInput = (const unsigned char*)"";
  }else if( nInput<0 ){
    pCsr->nInput = (int)strlen(aInput);
  }else{
@@ -341,7 +341,9 @@ static int fts3SqlStmt(
 ** created by merging the oldest :2 segments from absolute level :1. See 
 ** function sqlite3Fts3Incrmerge() for details.  */
 /* 29 */ "SELECT 2 * total(1 + leaves_end_block - start_block) "
-         "  FROM %Q.'%q_segdir' WHERE level = ? AND idx < ?",
+         "  FROM (SELECT * FROM %Q.'%q_segdir' "
+         "        WHERE level = ? ORDER BY idx ASC LIMIT ?"
+         "  )",

 /* SQL_DELETE_SEGDIR_ENTRY
 **   Delete the %_segdir entry on absolute level :1 with index :2.  */
@@ -2853,6 +2855,19 @@ int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr){
  return SQLITE_OK;
 }

+static int fts3GrowSegReaderBuffer(Fts3MultiSegReader *pCsr, int nReq){
+  if( nReq>pCsr->nBuffer ){
+    char *aNew;
+    pCsr->nBuffer = nReq*2;
+    aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer);
+    if( !aNew ){
+      return SQLITE_NOMEM;
+    }
+    pCsr->aBuffer = aNew;
+  }
+  return SQLITE_OK;
+}
+

 int sqlite3Fts3SegReaderStep(
  Fts3Table *p,                   /* Virtual table handle */
@@ -2987,15 +3002,9 @@ int sqlite3Fts3SegReaderStep(
          }

          nByte = sqlite3Fts3VarintLen(iDelta) + (isRequirePos?nList+1:0);
-          if( nDoclist+nByte>pCsr->nBuffer ){
-            char *aNew;
-            pCsr->nBuffer = (nDoclist+nByte)*2;
-            aNew = sqlite3_realloc(pCsr->aBuffer, pCsr->nBuffer);
-            if( !aNew ){
-              return SQLITE_NOMEM;
-            }
-            pCsr->aBuffer = aNew;
-          }
+
+          rc = fts3GrowSegReaderBuffer(pCsr, nByte+nDoclist);
+          if( rc ) return rc;

          if( isFirst ){
            char *a = &pCsr->aBuffer[nDoclist];
@@ -3020,6 +3029,9 @@ int sqlite3Fts3SegReaderStep(
        fts3SegReaderSort(apSegment, nMerge, j, xCmp);
      }
      if( nDoclist>0 ){
+        rc = fts3GrowSegReaderBuffer(pCsr, nDoclist+FTS3_NODE_PADDING);
+        if( rc ) return rc;
+        memset(&pCsr->aBuffer[nDoclist], 0, FTS3_NODE_PADDING);
        pCsr->aDoclist = pCsr->aBuffer;
        pCsr->nDoclist = nDoclist;
        rc = SQLITE_ROW;
@@ -4288,7 +4300,7 @@ static int fts3IncrmergeLoad(
      int i;
      int nHeight = (int)aRoot[0];
      NodeWriter *pNode;
-      if( nHeight<1 || nHeight>FTS_MAX_APPENDABLE_HEIGHT ){
+      if( nHeight<1 || nHeight>=FTS_MAX_APPENDABLE_HEIGHT ){
        sqlite3_reset(pSelect);
        return FTS_CORRUPT_VTAB;
      }
@@ -4323,17 +4335,20 @@ static int fts3IncrmergeLoad(
          while( reader.aNode && rc==SQLITE_OK ) rc = nodeReaderNext(&reader);
          blobGrowBuffer(&pNode->key, reader.term.n, &rc);
          if( rc==SQLITE_OK ){
-            memcpy(pNode->key.a, reader.term.a, reader.term.n);
+            assert_fts3_nc( reader.term.n>0 || reader.aNode==0 );
+            if( reader.term.n>0 ){
+              memcpy(pNode->key.a, reader.term.a, reader.term.n);
+            }
            pNode->key.n = reader.term.n;
            if( i>0 ){
              char *aBlock = 0;
              int nBlock = 0;
              pNode = &pWriter->aNodeWriter[i-1];
              pNode->iBlock = reader.iChild;
-              rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock, 0);
+              rc = sqlite3Fts3ReadBlock(p, reader.iChild, &aBlock, &nBlock,0);
              blobGrowBuffer(&pNode->block, 
                  MAX(nBlock, p->nNodeSize)+FTS3_NODE_PADDING, &rc
-              );
+                  );
              if( rc==SQLITE_OK ){
                memcpy(pNode->block.a, aBlock, nBlock);
                pNode->block.n = nBlock;
@@ -93,7 +93,7 @@ static int runSql(sqlite3 *db, const char *zFormat, ...){
 static void showSchema(sqlite3 *db, const char *zTab){
  sqlite3_stmt *pStmt;
  pStmt = prepare(db,
-            "SELECT sql FROM sqlite_master"
+            "SELECT sql FROM sqlite_schema"
            " WHERE name LIKE '%q%%'"
            " ORDER BY 1",
            zTab);
@@ -831,7 +831,7 @@ int main(int argc, char **argv){
    sqlite3_stmt *pStmt;
    int cnt = 0;
    pStmt = prepare(db, "SELECT b.sql"
-                        "  FROM sqlite_master a, sqlite_master b"
+                        "  FROM sqlite_schema a, sqlite_schema b"
                        " WHERE a.name GLOB '*_segdir'"
                        "   AND b.name=substr(a.name,1,length(a.name)-7)"
                        " ORDER BY 1");
@@ -742,6 +742,7 @@ proc print_categories {lMap} {
        }
        iTbl++;
      }
+      aAscii[0] = 0;                  /* 0x00 is never a token character */
    }
  }]
 }
@@ -184,6 +184,7 @@ struct Fts5Config {
  Fts5Tokenizer *pTok;
  fts5_tokenizer *pTokApi;
  int bLock;                      /* True when table is preparing statement */
+  int ePattern;                   /* FTS_PATTERN_XXX constant */

  /* Values loaded from the %_config table */
  int iCookie;                    /* Incremented when %_config is modified */
@@ -204,17 +205,19 @@ struct Fts5Config {
 };

 /* Current expected value of %_config table 'version' field */
-#define FTS5_CURRENT_VERSION 4
+#define FTS5_CURRENT_VERSION  4

 #define FTS5_CONTENT_NORMAL   0
 #define FTS5_CONTENT_NONE     1
 #define FTS5_CONTENT_EXTERNAL 2

-#define FTS5_DETAIL_FULL    0
-#define FTS5_DETAIL_NONE    1
-#define FTS5_DETAIL_COLUMNS 2
-
+#define FTS5_DETAIL_FULL      0
+#define FTS5_DETAIL_NONE      1
+#define FTS5_DETAIL_COLUMNS   2

+#define FTS5_PATTERN_NONE     0
+#define FTS5_PATTERN_LIKE     65  /* matches SQLITE_INDEX_CONSTRAINT_LIKE */
+#define FTS5_PATTERN_GLOB     66  /* matches SQLITE_INDEX_CONSTRAINT_GLOB */

 int sqlite3Fts5ConfigParse(
    Fts5Global*, sqlite3*, int, const char **, Fts5Config**, char**
@@ -484,7 +487,7 @@ int sqlite3Fts5IndexSetAverages(Fts5Index *p, const u8*, int);
 /*
 ** Functions called by the storage module as part of integrity-check.
 */
-int sqlite3Fts5IndexIntegrityCheck(Fts5Index*, u64 cksum);
+int sqlite3Fts5IndexIntegrityCheck(Fts5Index*, u64 cksum, int bUseCksum);

 /* 
 ** Called during virtual module initialization to register UDF 
@@ -554,8 +557,7 @@ int sqlite3Fts5GetTokenizer(
  Fts5Global*, 
  const char **azArg,
  int nArg,
-  Fts5Tokenizer**,
-  fts5_tokenizer**,
+  Fts5Config*,
  char **pzErr
 );

@@ -639,7 +641,7 @@ int sqlite3Fts5StorageDelete(Fts5Storage *p, i64, sqlite3_value**);
 int sqlite3Fts5StorageContentInsert(Fts5Storage *p, sqlite3_value**, i64*);
 int sqlite3Fts5StorageIndexInsert(Fts5Storage *p, sqlite3_value**, i64);

-int sqlite3Fts5StorageIntegrity(Fts5Storage *p);
+int sqlite3Fts5StorageIntegrity(Fts5Storage *p, int iArg);

 int sqlite3Fts5StorageStmt(Fts5Storage *p, int eStmt, sqlite3_stmt**, char**);
 void sqlite3Fts5StorageStmtRelease(Fts5Storage *p, int eStmt, sqlite3_stmt*);
@@ -684,11 +686,19 @@ struct Fts5Token {
 /* Parse a MATCH expression. */
 int sqlite3Fts5ExprNew(
  Fts5Config *pConfig, 
+  int bPhraseToAnd,
  int iCol,                       /* Column on LHS of MATCH operator */
  const char *zExpr,
  Fts5Expr **ppNew, 
  char **pzErr
 );
+int sqlite3Fts5ExprPattern(
+  Fts5Config *pConfig, 
+  int bGlob, 
+  int iCol, 
+  const char *zText, 
+  Fts5Expr **pp
+);

 /*
 ** for(rc = sqlite3Fts5ExprFirst(pExpr, pIdx, bDesc);
@@ -797,6 +807,10 @@ int sqlite3Fts5AuxInit(fts5_api*);
 */

 int sqlite3Fts5TokenizerInit(fts5_api*);
+int sqlite3Fts5TokenizerPattern(
+    int (*xCreate)(void*, const char**, int, Fts5Tokenizer**),
+    Fts5Tokenizer *pTok
+);
 /*
 ** End of interface to code in fts5_tokenizer.c.
 **************************************************************************/
@@ -566,7 +566,7 @@ static int fts5Bm25GetData(
  int rc = SQLITE_OK;             /* Return code */
  Fts5Bm25Data *p;                /* Object to return */

-  p = pApi->xGetAuxdata(pFts, 0);
+  p = (Fts5Bm25Data*)pApi->xGetAuxdata(pFts, 0);
  if( p==0 ){
    int nPhrase;                  /* Number of phrases in query */
    sqlite3_int64 nRow = 0;       /* Number of rows in table */
@@ -640,7 +640,7 @@ static void fts5Bm25Function(
 ){
  const double k1 = 1.2;          /* Constant "k1" from BM25 formula */
  const double b = 0.75;          /* Constant "b" from BM25 formula */
-  int rc = SQLITE_OK;             /* Error code */
+  int rc;                         /* Error code */
  double score = 0.0;             /* SQL function return value */
  Fts5Bm25Data *pData;            /* Values allocated/calculated once only */
  int i;                          /* Iterator variable */
@@ -672,17 +672,15 @@ static void fts5Bm25Function(
    D = (double)nTok;
  }

-  /* Determine the BM25 score for the current row. */
-  for(i=0; rc==SQLITE_OK && i<pData->nPhrase; i++){
-    score += pData->aIDF[i] * (
-      ( aFreq[i] * (k1 + 1.0) ) / 
-      ( aFreq[i] + k1 * (1 - b + b * D / pData->avgdl) )
-    );
-  }
-  
-  /* If no error has occurred, return the calculated score. Otherwise,
-  ** throw an SQL exception.  */
+  /* Determine and return the BM25 score for the current row. Or, if an
+  ** error has occurred, throw an exception. */
  if( rc==SQLITE_OK ){
+    for(i=0; i<pData->nPhrase; i++){
+      score += pData->aIDF[i] * (
+          ( aFreq[i] * (k1 + 1.0) ) / 
+          ( aFreq[i] + k1 * (1 - b + b * D / pData->avgdl) )
+      );
+    }
    sqlite3_result_double(pCtx, -1.0 * score);
  }else{
    sqlite3_result_error_code(pCtx, rc);
@@ -325,7 +325,7 @@ static int fts5ConfigParseSpecial(
          rc = SQLITE_ERROR;
        }else{
          rc = sqlite3Fts5GetTokenizer(pGlobal, 
-              (const char**)azArg, (int)nArg, &pConfig->pTok, &pConfig->pTokApi,
+              (const char**)azArg, (int)nArg, pConfig,
              pzErr
          );
        }
@@ -397,9 +397,7 @@ static int fts5ConfigParseSpecial(
 */
 static int fts5ConfigDefaultTokenizer(Fts5Global *pGlobal, Fts5Config *pConfig){
  assert( pConfig->pTok==0 && pConfig->pTokApi==0 );
-  return sqlite3Fts5GetTokenizer(
-      pGlobal, 0, 0, &pConfig->pTok, &pConfig->pTokApi, 0
-  );
+  return sqlite3Fts5GetTokenizer(pGlobal, 0, 0, pConfig, 0);
 }

 /*
@@ -128,6 +128,7 @@ struct Fts5Parse {
  int nPhrase;                    /* Size of apPhrase array */
  Fts5ExprPhrase **apPhrase;      /* Array of all phrases */
  Fts5ExprNode *pExpr;            /* Result of a successful parse */
+  int bPhraseToAnd;               /* Convert "a+b" to "a AND b" */
 };

 void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...){
@@ -216,6 +217,7 @@ static void fts5ParseFree(void *p){ sqlite3_free(p); }

 int sqlite3Fts5ExprNew(
  Fts5Config *pConfig,            /* FTS5 Configuration */
+  int bPhraseToAnd,
  int iCol,
  const char *zExpr,              /* Expression text */
  Fts5Expr **ppNew, 
@@ -231,6 +233,7 @@ int sqlite3Fts5ExprNew(
  *ppNew = 0;
  *pzErr = 0;
  memset(&sParse, 0, sizeof(sParse));
+  sParse.bPhraseToAnd = bPhraseToAnd;
  pEngine = sqlite3Fts5ParserAlloc(fts5ParseAlloc);
  if( pEngine==0 ){ return SQLITE_NOMEM; }
  sParse.pConfig = pConfig;
@@ -273,6 +276,7 @@ int sqlite3Fts5ExprNew(
      pNew->pConfig = pConfig;
      pNew->apExprPhrase = sParse.apPhrase;
      pNew->nPhrase = sParse.nPhrase;
+      pNew->bDesc = 0;
      sParse.apPhrase = 0;
    }
  }else{
@@ -284,6 +288,81 @@ int sqlite3Fts5ExprNew(
  return sParse.rc;
 }

+/*
+** This function is only called when using the special 'trigram' tokenizer.
+** Argument zText contains the text of a LIKE or GLOB pattern matched
+** against column iCol. This function creates and compiles an FTS5 MATCH
+** expression that will match a superset of the rows matched by the LIKE or
+** GLOB. If successful, SQLITE_OK is returned. Otherwise, an SQLite error
+** code.
+*/
+int sqlite3Fts5ExprPattern(
+  Fts5Config *pConfig, int bGlob, int iCol, const char *zText, Fts5Expr **pp
+){
+  i64 nText = strlen(zText);
+  char *zExpr = (char*)sqlite3_malloc64(nText*4 + 1);
+  int rc = SQLITE_OK;
+
+  if( zExpr==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    char aSpec[3];
+    int iOut = 0;
+    int i = 0;
+    int iFirst = 0;
+
+    if( bGlob==0 ){
+      aSpec[0] = '_';
+      aSpec[1] = '%';
+      aSpec[2] = 0;
+    }else{
+      aSpec[0] = '*';
+      aSpec[1] = '?';
+      aSpec[2] = '[';
+    }
+
+    while( i<=nText ){
+      if( i==nText 
+       || zText[i]==aSpec[0] || zText[i]==aSpec[1] || zText[i]==aSpec[2] 
+      ){
+        if( i-iFirst>=3 ){
+          int jj;
+          zExpr[iOut++] = '"';
+          for(jj=iFirst; jj<i; jj++){
+            zExpr[iOut++] = zText[jj];
+            if( zText[jj]=='"' ) zExpr[iOut++] = '"';
+          }
+          zExpr[iOut++] = '"';
+          zExpr[iOut++] = ' ';
+        }
+        if( zText[i]==aSpec[2] ){
+          i += 2;
+          if( zText[i-1]=='^' ) i++;
+          while( i<nText && zText[i]!=']' ) i++;
+        }
+        iFirst = i+1;
+      }
+      i++;
+    }
+    if( iOut>0 ){
+      int bAnd = 0;
+      if( pConfig->eDetail!=FTS5_DETAIL_FULL ){
+        bAnd = 1;
+        if( pConfig->eDetail==FTS5_DETAIL_NONE ){
+          iCol = pConfig->nCol;
+        }
+      }
+      zExpr[iOut] = '\0';
+      rc = sqlite3Fts5ExprNew(pConfig, bAnd, iCol, zExpr, pp,pConfig->pzErrmsg);
+    }else{
+      *pp = 0;
+    }
+    sqlite3_free(zExpr);
+  }
+
+  return rc;
+}
+
 /*
 ** Free the expression node object passed as the only argument.
 */
@@ -1421,8 +1500,8 @@ int sqlite3Fts5ExprFirst(Fts5Expr *p, Fts5Index *pIdx, i64 iFirst, int bDesc){
  }

  /* If the iterator is not at a real match, skip forward until it is. */
-  while( pRoot->bNomatch ){
-    assert( pRoot->bEof==0 && rc==SQLITE_OK );
+  while( pRoot->bNomatch && rc==SQLITE_OK ){
+    assert( pRoot->bEof==0 );
    rc = fts5ExprNodeNext(p, pRoot, 0, 0);
  }
  return rc;
@@ -1661,6 +1740,20 @@ void sqlite3Fts5ParseFinished(Fts5Parse *pParse, Fts5ExprNode *p){
  pParse->pExpr = p;
 }

+static int parseGrowPhraseArray(Fts5Parse *pParse){
+  if( (pParse->nPhrase % 8)==0 ){
+    sqlite3_int64 nByte = sizeof(Fts5ExprPhrase*) * (pParse->nPhrase + 8);
+    Fts5ExprPhrase **apNew;
+    apNew = (Fts5ExprPhrase**)sqlite3_realloc64(pParse->apPhrase, nByte);
+    if( apNew==0 ){
+      pParse->rc = SQLITE_NOMEM;
+      return SQLITE_NOMEM;
+    }
+    pParse->apPhrase = apNew;
+  }
+  return SQLITE_OK;
+}
+
 /*
 ** This function is called by the parser to process a string token. The
 ** string may or may not be quoted. In any case it is tokenized and a
@@ -1696,16 +1789,9 @@ Fts5ExprPhrase *sqlite3Fts5ParseTerm(
  }else{

    if( pAppend==0 ){
-      if( (pParse->nPhrase % 8)==0 ){
-        sqlite3_int64 nByte = sizeof(Fts5ExprPhrase*) * (pParse->nPhrase + 8);
-        Fts5ExprPhrase **apNew;
-        apNew = (Fts5ExprPhrase**)sqlite3_realloc64(pParse->apPhrase, nByte);
-        if( apNew==0 ){
-          pParse->rc = SQLITE_NOMEM;
-          fts5ExprPhraseFree(sCtx.pPhrase);
-          return 0;
-        }
-        pParse->apPhrase = apNew;
+      if( parseGrowPhraseArray(pParse) ){
+        fts5ExprPhraseFree(sCtx.pPhrase);
+        return 0;
      }
      pParse->nPhrase++;
    }
@@ -2112,6 +2198,67 @@ static void fts5ExprAddChildren(Fts5ExprNode *p, Fts5ExprNode *pSub){
  }
 }

+/*
+** This function is used when parsing LIKE or GLOB patterns against
+** trigram indexes that specify either detail=column or detail=none.
+** It converts a phrase:
+**
+**     abc + def + ghi
+**
+** into an AND tree:
+**
+**     abc AND def AND ghi
+*/
+static Fts5ExprNode *fts5ParsePhraseToAnd(
+  Fts5Parse *pParse, 
+  Fts5ExprNearset *pNear
+){
+  int nTerm = pNear->apPhrase[0]->nTerm;
+  int ii;
+  int nByte;
+  Fts5ExprNode *pRet;
+
+  assert( pNear->nPhrase==1 );
+  assert( pParse->bPhraseToAnd );
+
+  nByte = sizeof(Fts5ExprNode) + nTerm*sizeof(Fts5ExprNode*);
+  pRet = (Fts5ExprNode*)sqlite3Fts5MallocZero(&pParse->rc, nByte);
+  if( pRet ){
+    pRet->eType = FTS5_AND;
+    pRet->nChild = nTerm;
+    fts5ExprAssignXNext(pRet);
+    pParse->nPhrase--;
+    for(ii=0; ii<nTerm; ii++){
+      Fts5ExprPhrase *pPhrase = (Fts5ExprPhrase*)sqlite3Fts5MallocZero(
+          &pParse->rc, sizeof(Fts5ExprPhrase)
+      );
+      if( pPhrase ){
+        if( parseGrowPhraseArray(pParse) ){
+          fts5ExprPhraseFree(pPhrase);
+        }else{
+          pParse->apPhrase[pParse->nPhrase++] = pPhrase;
+          pPhrase->nTerm = 1;
+          pPhrase->aTerm[0].zTerm = sqlite3Fts5Strndup(
+              &pParse->rc, pNear->apPhrase[0]->aTerm[ii].zTerm, -1
+          );
+          pRet->apChild[ii] = sqlite3Fts5ParseNode(pParse, FTS5_STRING, 
+              0, 0, sqlite3Fts5ParseNearset(pParse, 0, pPhrase)
+          );
+        }
+      }
+    }
+  
+    if( pParse->rc ){
+      sqlite3Fts5ParseNodeFree(pRet);
+      pRet = 0;
+    }else{
+      sqlite3Fts5ParseNearsetFree(pNear);
+    }
+  }
+
+  return pRet;
+}
+
 /*
 ** Allocate and return a new expression object. If anything goes wrong (i.e.
 ** OOM error), leave an error code in pParse and return NULL.
@@ -2136,51 +2283,58 @@ Fts5ExprNode *sqlite3Fts5ParseNode(
    if( eType!=FTS5_STRING && pLeft==0 ) return pRight;
    if( eType!=FTS5_STRING && pRight==0 ) return pLeft;

-    if( eType==FTS5_NOT ){
-      nChild = 2;
-    }else if( eType==FTS5_AND || eType==FTS5_OR ){
-      nChild = 2;
-      if( pLeft->eType==eType ) nChild += pLeft->nChild-1;
-      if( pRight->eType==eType ) nChild += pRight->nChild-1;
-    }
+    if( eType==FTS5_STRING 
+     && pParse->bPhraseToAnd 
+     && pNear->apPhrase[0]->nTerm>1
+    ){
+      pRet = fts5ParsePhraseToAnd(pParse, pNear);
+    }else{
+      if( eType==FTS5_NOT ){
+        nChild = 2;
+      }else if( eType==FTS5_AND || eType==FTS5_OR ){
+        nChild = 2;
+        if( pLeft->eType==eType ) nChild += pLeft->nChild-1;
+        if( pRight->eType==eType ) nChild += pRight->nChild-1;
+      }

-    nByte = sizeof(Fts5ExprNode) + sizeof(Fts5ExprNode*)*(nChild-1);
-    pRet = (Fts5ExprNode*)sqlite3Fts5MallocZero(&pParse->rc, nByte);
+      nByte = sizeof(Fts5ExprNode) + sizeof(Fts5ExprNode*)*(nChild-1);
+      pRet = (Fts5ExprNode*)sqlite3Fts5MallocZero(&pParse->rc, nByte);

-    if( pRet ){
-      pRet->eType = eType;
-      pRet->pNear = pNear;
-      fts5ExprAssignXNext(pRet);
-      if( eType==FTS5_STRING ){
-        int iPhrase;
-        for(iPhrase=0; iPhrase<pNear->nPhrase; iPhrase++){
-          pNear->apPhrase[iPhrase]->pNode = pRet;
-          if( pNear->apPhrase[iPhrase]->nTerm==0 ){
-            pRet->xNext = 0;
-            pRet->eType = FTS5_EOF;
+      if( pRet ){
+        pRet->eType = eType;
+        pRet->pNear = pNear;
+        fts5ExprAssignXNext(pRet);
+        if( eType==FTS5_STRING ){
+          int iPhrase;
+          for(iPhrase=0; iPhrase<pNear->nPhrase; iPhrase++){
+            pNear->apPhrase[iPhrase]->pNode = pRet;
+            if( pNear->apPhrase[iPhrase]->nTerm==0 ){
+              pRet->xNext = 0;
+              pRet->eType = FTS5_EOF;
+            }
          }
-        }

-        if( pParse->pConfig->eDetail!=FTS5_DETAIL_FULL ){
-          Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];
-          if( pNear->nPhrase!=1 
-           || pPhrase->nTerm>1
-           || (pPhrase->nTerm>0 && pPhrase->aTerm[0].bFirst)
-          ){
-            assert( pParse->rc==SQLITE_OK );
-            pParse->rc = SQLITE_ERROR;
-            assert( pParse->zErr==0 );
-            pParse->zErr = sqlite3_mprintf(
-                "fts5: %s queries are not supported (detail!=full)", 
-                pNear->nPhrase==1 ? "phrase": "NEAR"
-                );
-            sqlite3_free(pRet);
-            pRet = 0;
+          if( pParse->pConfig->eDetail!=FTS5_DETAIL_FULL ){
+            Fts5ExprPhrase *pPhrase = pNear->apPhrase[0];
+            if( pNear->nPhrase!=1 
+                || pPhrase->nTerm>1
+                || (pPhrase->nTerm>0 && pPhrase->aTerm[0].bFirst)
+              ){
+              assert( pParse->rc==SQLITE_OK );
+              pParse->rc = SQLITE_ERROR;
+              assert( pParse->zErr==0 );
+              pParse->zErr = sqlite3_mprintf(
+                  "fts5: %s queries are not supported (detail!=full)", 
+                  pNear->nPhrase==1 ? "phrase": "NEAR"
+                  );
+              sqlite3_free(pRet);
+              pRet = 0;
+            }
          }
+        }else{
+          fts5ExprAddChildren(pRet, pLeft);
+          fts5ExprAddChildren(pRet, pRight);
        }
-      }else{
-        fts5ExprAddChildren(pRet, pLeft);
-        fts5ExprAddChildren(pRet, pRight);
      }
    }
  }
@@ -2401,8 +2555,17 @@ static char *fts5ExprPrint(Fts5Config *pConfig, Fts5ExprNode *pExpr){
    int iTerm;

    if( pNear->pColset ){
-      int iCol = pNear->pColset->aiCol[0];
-      zRet = fts5PrintfAppend(zRet, "%s : ", pConfig->azCol[iCol]);
+      int ii;
+      Fts5Colset *pColset = pNear->pColset;
+      if( pColset->nCol>1 ) zRet = fts5PrintfAppend(zRet, "{");
+      for(ii=0; ii<pColset->nCol; ii++){
+        zRet = fts5PrintfAppend(zRet, "%s%s", 
+            pConfig->azCol[pColset->aiCol[ii]], ii==pColset->nCol-1 ? "" : " "
+        );
+      }
+      if( zRet ){
+        zRet = fts5PrintfAppend(zRet, "%s : ", pColset->nCol>1 ? "}" : "");
+      }
      if( zRet==0 ) return 0;
    }

@@ -2525,7 +2688,7 @@ static void fts5ExprFunction(

  rc = sqlite3Fts5ConfigParse(pGlobal, db, nConfig, azConfig, &pConfig, &zErr);
  if( rc==SQLITE_OK ){
-    rc = sqlite3Fts5ExprNew(pConfig, pConfig->nCol, zExpr, &pExpr, &zErr);
+    rc = sqlite3Fts5ExprNew(pConfig, 0, pConfig->nCol, zExpr, &pExpr, &zErr);
  }
  if( rc==SQLITE_OK ){
    char *zText;
@@ -306,7 +306,6 @@ int sqlite3Fts5HashWrite(
      p->iCol = (pHash->eDetail==FTS5_DETAIL_FULL ? 0 : -1);
    }

-    nIncr += p->nData;
  }else{

    /* Appending to an existing hash-entry. Check that there is enough 
@@ -339,8 +338,9 @@ int sqlite3Fts5HashWrite(
  /* If this is a new rowid, append the 4-byte size field for the previous
  ** entry, and the new rowid for this entry.  */
  if( iRowid!=p->iRowid ){
+    u64 iDiff = (u64)iRowid - (u64)p->iRowid;
    fts5HashAddPoslistSize(pHash, p, 0);
-    p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iRowid - p->iRowid);
+    p->nData += sqlite3Fts5PutVarint(&pPtr[p->nData], iDiff);
    p->iRowid = iRowid;
    bNew = 1;
    p->iSzPoslist = p->nData;
@@ -1754,7 +1754,7 @@ static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){

  ASSERT_SZLEAF_OK(pIter->pLeaf);
  while( 1 ){
-    i64 iDelta = 0;
+    u64 iDelta = 0;

    if( eDetail==FTS5_DETAIL_NONE ){
      /* todo */
@@ -1769,7 +1769,7 @@ static void fts5SegIterReverseInitPage(Fts5Index *p, Fts5SegIter *pIter){
      i += nPos;
    }
    if( i>=n ) break;
-    i += fts5GetVarint(&a[i], (u64*)&iDelta);
+    i += fts5GetVarint(&a[i], &iDelta);
    pIter->iRowid += iDelta;

    /* If necessary, grow the pIter->aRowidOffset[] array. */
@@ -1868,7 +1868,7 @@ static void fts5SegIterNext_Reverse(
  if( pIter->iRowidOffset>0 ){
    u8 *a = pIter->pLeaf->p;
    int iOff;
-    i64 iDelta;
+    u64 iDelta;

    pIter->iRowidOffset--;
    pIter->iLeafOffset = pIter->aRowidOffset[pIter->iRowidOffset];
@@ -1877,7 +1877,7 @@ static void fts5SegIterNext_Reverse(
    if( p->pConfig->eDetail!=FTS5_DETAIL_NONE ){
      iOff += pIter->nPos;
    }
-    fts5GetVarint(&a[iOff], (u64*)&iDelta);
+    fts5GetVarint(&a[iOff], &iDelta);
    pIter->iRowid -= iDelta;
  }else{
    fts5SegIterReverseNewPage(p, pIter);
@@ -2070,14 +2070,10 @@ static void fts5SegIterNext(
    }else{
      /* The following could be done by calling fts5SegIterLoadNPos(). But
      ** this block is particularly performance critical, so equivalent
-      ** code is inlined. 
-      **
-      ** Later: Switched back to fts5SegIterLoadNPos() because it supports
-      ** detail=none mode. Not ideal.
-      */
+      ** code is inlined.  */
      int nSz;
      assert( p->rc==SQLITE_OK );
-      assert( pIter->iLeafOffset<=pIter->pLeaf->nn );
+      assert_nc( pIter->iLeafOffset<=pIter->pLeaf->nn );
      fts5FastGetVarint32(pIter->pLeaf->p, pIter->iLeafOffset, nSz);
      pIter->bDel = (nSz & 0x0001);
      pIter->nPos = nSz>>1;
@@ -2321,11 +2317,11 @@ static void fts5LeafSeek(
  }

 search_success:
-  pIter->iLeafOffset = iOff + nNew;
-  if( pIter->iLeafOffset>n || nNew<1 ){
+  if( (i64)iOff+nNew>n || nNew<1 ){
    p->rc = FTS5_CORRUPT;
    return;
  }
+  pIter->iLeafOffset = iOff + nNew;
  pIter->iTermLeafOffset = pIter->iLeafOffset;
  pIter->iTermLeafPgno = pIter->iLeafPgno;

@@ -3069,7 +3065,7 @@ static void fts5ChunkIterate(
  int pgno = pSeg->iLeafPgno;
  int pgnoSave = 0;

-  /* This function does notmwork with detail=none databases. */
+  /* This function does not work with detail=none databases. */
  assert( p->pConfig->eDetail!=FTS5_DETAIL_NONE );

  if( (pSeg->flags & FTS5_SEGITER_REVERSE)==0 ){
@@ -3082,6 +3078,9 @@ static void fts5ChunkIterate(
    fts5DataRelease(pData);
    if( nRem<=0 ){
      break;
+    }else if( pSeg->pSeg==0 ){
+      p->rc = FTS5_CORRUPT;
+      return;
    }else{
      pgno++;
      pData = fts5LeafRead(p, FTS5_SEGMENT_ROWID(pSeg->pSeg->iSegid, pgno));
@@ -3133,66 +3132,72 @@ static void fts5SegiterPoslist(
 }

 /*
-** IN/OUT parameter (*pa) points to a position list n bytes in size. If
-** the position list contains entries for column iCol, then (*pa) is set
-** to point to the sub-position-list for that column and the number of
-** bytes in it returned. Or, if the argument position list does not
-** contain any entries for column iCol, return 0.
+** Parameter pPos points to a buffer containing a position list, size nPos.
+** This function filters it according to pColset (which must be non-NULL)
+** and sets pIter->base.pData/nData to point to the new position list.
+** If memory is required for the new position list, use buffer pIter->poslist.
+** Or, if the new position list is a contiguous subset of the input, set
+** pIter->base.pData/nData to point directly to it.
+**
+** This function is a no-op if *pRc is other than SQLITE_OK when it is
+** called. If an OOM error is encountered, *pRc is set to SQLITE_NOMEM
+** before returning.
 */
-static int fts5IndexExtractCol(
-  const u8 **pa,                  /* IN/OUT: Pointer to poslist */
-  int n,                          /* IN: Size of poslist in bytes */
-  int iCol                        /* Column to extract from poslist */
-){
-  int iCurrent = 0;               /* Anything before the first 0x01 is col 0 */
-  const u8 *p = *pa;
-  const u8 *pEnd = &p[n];         /* One byte past end of position list */
-
-  while( iCol>iCurrent ){
-    /* Advance pointer p until it points to pEnd or an 0x01 byte that is
-    ** not part of a varint. Note that it is not possible for a negative
-    ** or extremely large varint to occur within an uncorrupted position 
-    ** list. So the last byte of each varint may be assumed to have a clear
-    ** 0x80 bit.  */
-    while( *p!=0x01 ){
-      while( *p++ & 0x80 );
-      if( p>=pEnd ) return 0;
-    }
-    *pa = p++;
-    iCurrent = *p++;
-    if( iCurrent & 0x80 ){
-      p--;
-      p += fts5GetVarint32(p, iCurrent);
-    }
-  }
-  if( iCol!=iCurrent ) return 0;
-
-  /* Advance pointer p until it points to pEnd or an 0x01 byte that is
-  ** not part of a varint */
-  while( p<pEnd && *p!=0x01 ){
-    while( *p++ & 0x80 );
-  }
-
-  return p - (*pa);
-}
-
 static void fts5IndexExtractColset(
  int *pRc,
  Fts5Colset *pColset,            /* Colset to filter on */
  const u8 *pPos, int nPos,       /* Position list */
-  Fts5Buffer *pBuf                /* Output buffer */
+  Fts5Iter *pIter
 ){
  if( *pRc==SQLITE_OK ){
-    int i;
-    fts5BufferZero(pBuf);
-    for(i=0; i<pColset->nCol; i++){
-      const u8 *pSub = pPos;
-      int nSub = fts5IndexExtractCol(&pSub, nPos, pColset->aiCol[i]);
-      if( nSub ){
-        fts5BufferAppendBlob(pRc, pBuf, nSub, pSub);
+    const u8 *p = pPos;
+    const u8 *aCopy = p;
+    const u8 *pEnd = &p[nPos];    /* One byte past end of position list */
+    int i = 0;
+    int iCurrent = 0;
+
+    if( pColset->nCol>1 && sqlite3Fts5BufferSize(pRc, &pIter->poslist, nPos) ){
+      return;
+    }
+
+    while( 1 ){
+      while( pColset->aiCol[i]<iCurrent ){
+        i++;
+        if( i==pColset->nCol ){
+          pIter->base.pData = pIter->poslist.p;
+          pIter->base.nData = pIter->poslist.n;
+          return;
+        }
+      }
+
+      /* Advance pointer p until it points to pEnd or an 0x01 byte that is
+      ** not part of a varint */
+      while( p<pEnd && *p!=0x01 ){
+        while( *p++ & 0x80 );
+      }
+
+      if( pColset->aiCol[i]==iCurrent ){
+        if( pColset->nCol==1 ){
+          pIter->base.pData = aCopy;
+          pIter->base.nData = p-aCopy;
+          return;
+        }
+        fts5BufferSafeAppendBlob(&pIter->poslist, aCopy, p-aCopy);
+      }
+      if( p==pEnd ){
+        pIter->base.pData = pIter->poslist.p;
+        pIter->base.nData = pIter->poslist.n;
+        return;
+      }
+      aCopy = p++;
+      iCurrent = *p++;
+      if( iCurrent & 0x80 ){
+        p--;
+        p += fts5GetVarint32(p, iCurrent);
      }
    }
  }
+
 }

 /*
@@ -3312,16 +3317,9 @@ static void fts5IterSetOutputs_Full(Fts5Iter *pIter, Fts5SegIter *pSeg){
    /* All data is stored on the current page. Populate the output 
    ** variables to point into the body of the page object. */
    const u8 *a = &pSeg->pLeaf->p[pSeg->iLeafOffset];
-    if( pColset->nCol==1 ){
-      pIter->base.nData = fts5IndexExtractCol(&a, pSeg->nPos,pColset->aiCol[0]);
-      pIter->base.pData = a;
-    }else{
-      int *pRc = &pIter->pIndex->rc;
-      fts5BufferZero(&pIter->poslist);
-      fts5IndexExtractColset(pRc, pColset, a, pSeg->nPos, &pIter->poslist);
-      pIter->base.pData = pIter->poslist.p;
-      pIter->base.nData = pIter->poslist.n;
-    }
+    int *pRc = &pIter->pIndex->rc;
+    fts5BufferZero(&pIter->poslist);
+    fts5IndexExtractColset(pRc, pColset, a, pSeg->nPos, pIter);
  }else{
    /* The data is distributed over two or more pages. Copy it into the
    ** Fts5Iter.poslist buffer and then set the output pointer to point
@@ -4804,7 +4802,7 @@ static void fts5AppendPoslist(
 static void fts5DoclistIterNext(Fts5DoclistIter *pIter){
  u8 *p = pIter->aPoslist + pIter->nSize + pIter->nPoslist;

-  assert( pIter->aPoslist );
+  assert( pIter->aPoslist || (p==0 && pIter->aPoslist==0) );
  if( p>=pIter->aEof ){
    pIter->aPoslist = 0;
  }else{
@@ -4824,6 +4822,9 @@ static void fts5DoclistIterNext(Fts5DoclistIter *pIter){
    }

    pIter->aPoslist = p;
+    if( &pIter->aPoslist[pIter->nPoslist]>pIter->aEof ){
+      pIter->aPoslist = 0;
+    }
  }
 }

@@ -4832,9 +4833,11 @@ static void fts5DoclistIterInit(
  Fts5DoclistIter *pIter
 ){
  memset(pIter, 0, sizeof(*pIter));
-  pIter->aPoslist = pBuf->p;
-  pIter->aEof = &pBuf->p[pBuf->n];
-  fts5DoclistIterNext(pIter);
+  if( pBuf->n>0 ){
+    pIter->aPoslist = pBuf->p;
+    pIter->aEof = &pBuf->p[pBuf->n];
+    fts5DoclistIterNext(pIter);
+  }
 }

 #if 0
@@ -4888,16 +4891,20 @@ static void fts5NextRowid(Fts5Buffer *pBuf, int *piOff, i64 *piRowid){
 static void fts5MergeRowidLists(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5Buffer *p1,                 /* First list to merge */
-  Fts5Buffer *p2                  /* Second list to merge */
+  int nBuf,                       /* Number of entries in apBuf[] */
+  Fts5Buffer *aBuf                /* Array of other lists to merge into p1 */
 ){
  int i1 = 0;
  int i2 = 0;
  i64 iRowid1 = 0;
  i64 iRowid2 = 0;
  i64 iOut = 0;
-
+  Fts5Buffer *p2 = &aBuf[0];
  Fts5Buffer out;
+
+  (void)nBuf;
  memset(&out, 0, sizeof(out));
+  assert( nBuf==1 );
  sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n);
  if( p->rc ) return;

@@ -4924,177 +4931,213 @@ static void fts5MergeRowidLists(
  fts5BufferFree(&out);
 }

+typedef struct PrefixMerger PrefixMerger;
+struct PrefixMerger {
+  Fts5DoclistIter iter;           /* Doclist iterator */
+  i64 iPos;                       /* For iterating through a position list */
+  int iOff;
+  u8 *aPos;
+  PrefixMerger *pNext;            /* Next in docid/poslist order */
+};
+
+static void fts5PrefixMergerInsertByRowid(
+  PrefixMerger **ppHead, 
+  PrefixMerger *p
+){
+  if( p->iter.aPoslist ){
+    PrefixMerger **pp = ppHead;
+    while( *pp && p->iter.iRowid>(*pp)->iter.iRowid ){
+      pp = &(*pp)->pNext;
+    }
+    p->pNext = *pp;
+    *pp = p;
+  }
+}
+
+static void fts5PrefixMergerInsertByPosition(
+  PrefixMerger **ppHead, 
+  PrefixMerger *p
+){
+  if( p->iPos>=0 ){
+    PrefixMerger **pp = ppHead;
+    while( *pp && p->iPos>(*pp)->iPos ){
+      pp = &(*pp)->pNext;
+    }
+    p->pNext = *pp;
+    *pp = p;
+  }
+}
+
+
 /*
-** Buffers p1 and p2 contain doclists. This function merges the content
-** of the two doclists together and sets buffer p1 to the result before
-** returning.
-**
-** If an error occurs, an error code is left in p->rc. If an error has
-** already occurred, this function is a no-op.
+** Array aBuf[] contains nBuf doclists. These are all merged in with the
+** doclist in buffer p1.
 */
 static void fts5MergePrefixLists(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5Buffer *p1,                 /* First list to merge */
-  Fts5Buffer *p2                  /* Second list to merge */
+  int nBuf,                       /* Number of buffers in array aBuf[] */
+  Fts5Buffer *aBuf                /* Other lists to merge in */ 
 ){
-  if( p2->n ){
-    i64 iLastRowid = 0;
-    Fts5DoclistIter i1;
-    Fts5DoclistIter i2;
-    Fts5Buffer out = {0, 0, 0};
-    Fts5Buffer tmp = {0, 0, 0};
+#define fts5PrefixMergerNextPosition(p) \
+  sqlite3Fts5PoslistNext64((p)->aPos,(p)->iter.nPoslist,&(p)->iOff,&(p)->iPos);
+#define FTS5_MERGE_NLIST 16
+  PrefixMerger aMerger[FTS5_MERGE_NLIST];
+  PrefixMerger *pHead = 0;
+  int i;
+  int nOut = 0;
+  Fts5Buffer out = {0, 0, 0};
+  Fts5Buffer tmp = {0, 0, 0};
+  i64 iLastRowid = 0;

-    /* The maximum size of the output is equal to the sum of the two 
-    ** input sizes + 1 varint (9 bytes). The extra varint is because if the
-    ** first rowid in one input is a large negative number, and the first in
-    ** the other a non-negative number, the delta for the non-negative
-    ** number will be larger on disk than the literal integer value
-    ** was.  
-    **
-    ** Or, if the input position-lists are corrupt, then the output might
-    ** include up to 2 extra 10-byte positions created by interpreting -1
-    ** (the value PoslistNext64() uses for EOF) as a position and appending
-    ** it to the output. This can happen at most once for each input 
-    ** position-list, hence two 10 byte paddings.  */
-    if( sqlite3Fts5BufferSize(&p->rc, &out, p1->n + p2->n + 9+10+10) ) return;
-    fts5DoclistIterInit(p1, &i1);
-    fts5DoclistIterInit(p2, &i2);
-
-    while( 1 ){
-      if( i1.iRowid<i2.iRowid ){
-        /* Copy entry from i1 */
-        fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
-        fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.nPoslist+i1.nSize);
-        fts5DoclistIterNext(&i1);
-        if( i1.aPoslist==0 ) break;
-        assert( out.n<=((i1.aPoslist-p1->p) + (i2.aPoslist-p2->p)+9+10+10) );
-      }
-      else if( i2.iRowid!=i1.iRowid ){
-        /* Copy entry from i2 */
-        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
-        fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.nPoslist+i2.nSize);
-        fts5DoclistIterNext(&i2);
-        if( i2.aPoslist==0 ) break;
-        assert( out.n<=((i1.aPoslist-p1->p) + (i2.aPoslist-p2->p)+9+10+10) );
-      }
-      else{
-        /* Merge the two position lists. */ 
-        i64 iPos1 = 0;
-        i64 iPos2 = 0;
-        int iOff1 = 0;
-        int iOff2 = 0;
-        u8 *a1 = &i1.aPoslist[i1.nSize];
-        u8 *a2 = &i2.aPoslist[i2.nSize];
-        int nCopy;
-        u8 *aCopy;
-
-        i64 iPrev = 0;
-        Fts5PoslistWriter writer;
-        memset(&writer, 0, sizeof(writer));
-
-        /* See the earlier comment in this function for an explanation of why
-        ** corrupt input position lists might cause the output to consume
-        ** at most 20 bytes of unexpected space. */
-        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
-        fts5BufferZero(&tmp);
-        sqlite3Fts5BufferSize(&p->rc, &tmp, i1.nPoslist + i2.nPoslist + 10 + 10);
-        if( p->rc ) break;
-
-        sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
-        sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
-        assert_nc( iPos1>=0 && iPos2>=0 );
-
-        if( iPos1<iPos2 ){
-          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);
-          sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
-        }else{
-          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);
-          sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
-        }
-        if( iPos1>=0 && iPos2>=0 ){
-          while( 1 ){
-            if( iPos1<iPos2 ){
-              if( iPos1!=iPrev ){
-                sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);
-              }
-              sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
-              if( iPos1<0 ) break;
-            }else{
-              assert_nc( iPos2!=iPrev );
-              sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);
-              sqlite3Fts5PoslistNext64(a2, i2.nPoslist, &iOff2, &iPos2);
-              if( iPos2<0 ) break;
-            }
-          }
-        }
-
-        if( iPos1>=0 ){
-          if( iPos1!=iPrev ){
-            sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos1);
-          }
-          aCopy = &a1[iOff1];
-          nCopy = i1.nPoslist - iOff1;
-        }else{
-          assert_nc( iPos2>=0 && iPos2!=iPrev );
-          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, iPos2);
-          aCopy = &a2[iOff2];
-          nCopy = i2.nPoslist - iOff2;
-        }
-        if( nCopy>0 ){
-          fts5BufferSafeAppendBlob(&tmp, aCopy, nCopy);
-        }
-
-        /* WRITEPOSLISTSIZE */
-        assert_nc( tmp.n<=i1.nPoslist+i2.nPoslist );
-        assert( tmp.n<=i1.nPoslist+i2.nPoslist+10+10 );
-        if( tmp.n>i1.nPoslist+i2.nPoslist ){
-          if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
-          break;
-        }
-        fts5BufferSafeAppendVarint(&out, tmp.n * 2);
-        fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
-        fts5DoclistIterNext(&i1);
-        fts5DoclistIterNext(&i2);
-        assert_nc( out.n<=(p1->n+p2->n+9) );
-        if( i1.aPoslist==0 || i2.aPoslist==0 ) break;
-        assert( out.n<=((i1.aPoslist-p1->p) + (i2.aPoslist-p2->p)+9+10+10) );
-      }
-    }
-
-    if( i1.aPoslist ){
-      fts5MergeAppendDocid(&out, iLastRowid, i1.iRowid);
-      fts5BufferSafeAppendBlob(&out, i1.aPoslist, i1.aEof - i1.aPoslist);
-    }
-    else if( i2.aPoslist ){
-      fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
-      fts5BufferSafeAppendBlob(&out, i2.aPoslist, i2.aEof - i2.aPoslist);
-    }
-    assert_nc( out.n<=(p1->n+p2->n+9) );
-
-    fts5BufferSet(&p->rc, p1, out.n, out.p);
-    fts5BufferFree(&tmp);
-    fts5BufferFree(&out);
+  /* Initialize a doclist-iterator for each input buffer. Arrange them in
+  ** a linked-list starting at pHead in ascending order of rowid. Avoid
+  ** linking any iterators already at EOF into the linked list at all. */ 
+  assert( nBuf+1<=sizeof(aMerger)/sizeof(aMerger[0]) );
+  memset(aMerger, 0, sizeof(PrefixMerger)*(nBuf+1));
+  pHead = &aMerger[nBuf];
+  fts5DoclistIterInit(p1, &pHead->iter);
+  for(i=0; i<nBuf; i++){
+    fts5DoclistIterInit(&aBuf[i], &aMerger[i].iter);
+    fts5PrefixMergerInsertByRowid(&pHead, &aMerger[i]);
+    nOut += aBuf[i].n;
  }
+  if( nOut==0 ) return;
+  nOut += p1->n + 9 + 10*nBuf;
+
+  /* The maximum size of the output is equal to the sum of the
+  ** input sizes + 1 varint (9 bytes). The extra varint is because if the
+  ** first rowid in one input is a large negative number, and the first in
+  ** the other a non-negative number, the delta for the non-negative
+  ** number will be larger on disk than the literal integer value
+  ** was.  
+  **
+  ** Or, if the input position-lists are corrupt, then the output might
+  ** include up to (nBuf+1) extra 10-byte positions created by interpreting -1
+  ** (the value PoslistNext64() uses for EOF) as a position and appending
+  ** it to the output. This can happen at most once for each input 
+  ** position-list, hence (nBuf+1) 10 byte paddings.  */
+  if( sqlite3Fts5BufferSize(&p->rc, &out, nOut) ) return;
+
+  while( pHead ){
+    fts5MergeAppendDocid(&out, iLastRowid, pHead->iter.iRowid);
+
+    if( pHead->pNext && iLastRowid==pHead->pNext->iter.iRowid ){
+      /* Merge data from two or more poslists */
+      i64 iPrev = 0;
+      int nTmp = FTS5_DATA_ZERO_PADDING;
+      int nMerge = 0;
+      PrefixMerger *pSave = pHead;
+      PrefixMerger *pThis = 0;
+      int nTail = 0;
+
+      pHead = 0;
+      while( pSave && pSave->iter.iRowid==iLastRowid ){
+        PrefixMerger *pNext = pSave->pNext;
+        pSave->iOff = 0;
+        pSave->iPos = 0;
+        pSave->aPos = &pSave->iter.aPoslist[pSave->iter.nSize];
+        fts5PrefixMergerNextPosition(pSave);
+        nTmp += pSave->iter.nPoslist + 10;
+        nMerge++;
+        fts5PrefixMergerInsertByPosition(&pHead, pSave);
+        pSave = pNext;
+      }
+
+      if( pHead==0 || pHead->pNext==0 ){
+        p->rc = FTS5_CORRUPT;
+        break;
+      }
+
+      /* See the earlier comment in this function for an explanation of why
+      ** corrupt input position lists might cause the output to consume
+      ** at most nMerge*10 bytes of unexpected space. */
+      if( sqlite3Fts5BufferSize(&p->rc, &tmp, nTmp+nMerge*10) ){
+        break;
+      }
+      fts5BufferZero(&tmp);
+
+      pThis = pHead;
+      pHead = pThis->pNext;
+      sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, pThis->iPos);
+      fts5PrefixMergerNextPosition(pThis);
+      fts5PrefixMergerInsertByPosition(&pHead, pThis);
+
+      while( pHead->pNext ){
+        pThis = pHead;
+        if( pThis->iPos!=iPrev ){
+          sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, pThis->iPos);
+        }
+        fts5PrefixMergerNextPosition(pThis);
+        pHead = pThis->pNext;
+        fts5PrefixMergerInsertByPosition(&pHead, pThis);
+      }
+
+      if( pHead->iPos!=iPrev ){
+        sqlite3Fts5PoslistSafeAppend(&tmp, &iPrev, pHead->iPos);
+      }
+      nTail = pHead->iter.nPoslist - pHead->iOff;
+
+      /* WRITEPOSLISTSIZE */
+      assert( tmp.n+nTail<=nTmp );
+      if( tmp.n+nTail>nTmp-FTS5_DATA_ZERO_PADDING ){
+        if( p->rc==SQLITE_OK ) p->rc = FTS5_CORRUPT;
+        break;
+      }
+      fts5BufferSafeAppendVarint(&out, (tmp.n+nTail) * 2);
+      fts5BufferSafeAppendBlob(&out, tmp.p, tmp.n);
+      if( nTail>0 ){
+        fts5BufferSafeAppendBlob(&out, &pHead->aPos[pHead->iOff], nTail);
+      }
+
+      pHead = pSave;
+      for(i=0; i<nBuf+1; i++){
+        PrefixMerger *pX = &aMerger[i];
+        if( pX->iter.aPoslist && pX->iter.iRowid==iLastRowid ){
+          fts5DoclistIterNext(&pX->iter);
+          fts5PrefixMergerInsertByRowid(&pHead, pX);
+        }
+      }
+
+    }else{
+      /* Copy poslist from pHead to output */
+      PrefixMerger *pThis = pHead;
+      Fts5DoclistIter *pI = &pThis->iter;
+      fts5BufferSafeAppendBlob(&out, pI->aPoslist, pI->nPoslist+pI->nSize);
+      fts5DoclistIterNext(pI);
+      pHead = pThis->pNext;
+      fts5PrefixMergerInsertByRowid(&pHead, pThis);
+    }
+  }
+
+  fts5BufferFree(p1);
+  fts5BufferFree(&tmp);
+  memset(&out.p[out.n], 0, FTS5_DATA_ZERO_PADDING);
+  *p1 = out;
 }

 static void fts5SetupPrefixIter(
  Fts5Index *p,                   /* Index to read from */
  int bDesc,                      /* True for "ORDER BY rowid DESC" */
-  const u8 *pToken,               /* Buffer containing prefix to match */
+  int iIdx,                       /* Index to scan for data */
+  u8 *pToken,                     /* Buffer containing prefix to match */
  int nToken,                     /* Size of buffer pToken in bytes */
  Fts5Colset *pColset,            /* Restrict matches to these columns */
  Fts5Iter **ppIter          /* OUT: New iterator */
 ){
  Fts5Structure *pStruct;
  Fts5Buffer *aBuf;
-  const int nBuf = 32;
+  int nBuf = 32;
+  int nMerge = 1;

-  void (*xMerge)(Fts5Index*, Fts5Buffer*, Fts5Buffer*);
+  void (*xMerge)(Fts5Index*, Fts5Buffer*, int, Fts5Buffer*);
  void (*xAppend)(Fts5Index*, i64, Fts5Iter*, Fts5Buffer*);
  if( p->pConfig->eDetail==FTS5_DETAIL_NONE ){
    xMerge = fts5MergeRowidLists;
    xAppend = fts5AppendRowid;
  }else{
+    nMerge = FTS5_MERGE_NLIST-1;
+    nBuf = nMerge*8;   /* Sufficient to merge (16^8)==(2^32) lists */
    xMerge = fts5MergePrefixLists;
    xAppend = fts5AppendPoslist;
  }
@@ -5114,6 +5157,27 @@ static void fts5SetupPrefixIter(
    int bNewTerm = 1;

    memset(&doclist, 0, sizeof(doclist));
+    if( iIdx!=0 ){
+      int dummy = 0;
+      const int f2 = FTS5INDEX_QUERY_SKIPEMPTY|FTS5INDEX_QUERY_NOOUTPUT;
+      pToken[0] = FTS5_MAIN_PREFIX;
+      fts5MultiIterNew(p, pStruct, f2, pColset, pToken, nToken, -1, 0, &p1);
+      fts5IterSetOutputCb(&p->rc, p1);
+      for(;
+        fts5MultiIterEof(p, p1)==0;
+        fts5MultiIterNext2(p, p1, &dummy)
+      ){
+        Fts5SegIter *pSeg = &p1->aSeg[ p1->aFirst[1].iFirst ];
+        p1->xSetOutputs(p1, pSeg);
+        if( p1->base.nData ){
+          xAppend(p, p1->base.iRowid-iLastRowid, p1, &doclist);
+          iLastRowid = p1->base.iRowid;
+        }
+      }
+      fts5MultiIterFree(p1);
+    }
+
+    pToken[0] = FTS5_MAIN_PREFIX + iIdx;
    fts5MultiIterNew(p, pStruct, flags, pColset, pToken, nToken, -1, 0, &p1);
    fts5IterSetOutputCb(&p->rc, p1);
    for( /* no-op */ ;
@@ -5134,13 +5198,21 @@ static void fts5SetupPrefixIter(

      if( p1->base.iRowid<=iLastRowid && doclist.n>0 ){
        for(i=0; p->rc==SQLITE_OK && doclist.n; i++){
-          assert( i<nBuf );
-          if( aBuf[i].n==0 ){
-            fts5BufferSwap(&doclist, &aBuf[i]);
-            fts5BufferZero(&doclist);
-          }else{
-            xMerge(p, &doclist, &aBuf[i]);
-            fts5BufferZero(&aBuf[i]);
+          int i1 = i*nMerge;
+          int iStore;
+          assert( i1+nMerge<=nBuf );
+          for(iStore=i1; iStore<i1+nMerge; iStore++){
+            if( aBuf[iStore].n==0 ){
+              fts5BufferSwap(&doclist, &aBuf[iStore]);
+              fts5BufferZero(&doclist);
+              break;
+            }
+          }
+          if( iStore==i1+nMerge ){
+            xMerge(p, &doclist, nMerge, &aBuf[i1]);
+            for(iStore=i1; iStore<i1+nMerge; iStore++){
+              fts5BufferZero(&aBuf[iStore]);
+            }
          }
        }
        iLastRowid = 0;
@@ -5150,11 +5222,15 @@ static void fts5SetupPrefixIter(
      iLastRowid = p1->base.iRowid;
    }

-    for(i=0; i<nBuf; i++){
+    assert( (nBuf%nMerge)==0 );
+    for(i=0; i<nBuf; i+=nMerge){
+      int iFree;
      if( p->rc==SQLITE_OK ){
-        xMerge(p, &doclist, &aBuf[i]);
+        xMerge(p, &doclist, nMerge, &aBuf[i]);
+      }
+      for(iFree=i; iFree<i+nMerge; iFree++){
+        fts5BufferFree(&aBuf[iFree]);
      }
-      fts5BufferFree(&aBuf[i]);
    }
    fts5MultiIterFree(p1);

@@ -5409,6 +5485,7 @@ int sqlite3Fts5IndexQuery(

  if( sqlite3Fts5BufferSize(&p->rc, &buf, nToken+1)==0 ){
    int iIdx = 0;                 /* Index to search */
+    int iPrefixIdx = 0;           /* +1 prefix index */
    if( nToken ) memcpy(&buf.p[1], pToken, nToken);

    /* Figure out which index to search and set iIdx accordingly. If this
@@ -5430,7 +5507,9 @@ int sqlite3Fts5IndexQuery(
    if( flags & FTS5INDEX_QUERY_PREFIX ){
      int nChar = fts5IndexCharlen(pToken, nToken);
      for(iIdx=1; iIdx<=pConfig->nPrefix; iIdx++){
-        if( pConfig->aPrefix[iIdx-1]==nChar ) break;
+        int nIdxChar = pConfig->aPrefix[iIdx-1];
+        if( nIdxChar==nChar ) break;
+        if( nIdxChar==nChar+1 ) iPrefixIdx = iIdx;
      }
    }

@@ -5447,8 +5526,7 @@ int sqlite3Fts5IndexQuery(
    }else{
      /* Scan multiple terms in the main index */
      int bDesc = (flags & FTS5INDEX_QUERY_DESC)!=0;
-      buf.p[0] = FTS5_MAIN_PREFIX;
-      fts5SetupPrefixIter(p, bDesc, buf.p, nToken+1, pColset, &pRet);
+      fts5SetupPrefixIter(p, bDesc, iPrefixIdx, buf.p, nToken+1, pColset,&pRet);
      assert( p->rc!=SQLITE_OK || pRet->pColset==0 );
      fts5IterSetOutputCb(&p->rc, pRet);
      if( p->rc==SQLITE_OK ){
@@ -5521,8 +5599,9 @@ int sqlite3Fts5IterNextFrom(Fts5IndexIter *pIndexIter, i64 iMatch){
 const char *sqlite3Fts5IterTerm(Fts5IndexIter *pIndexIter, int *pn){
  int n;
  const char *z = (const char*)fts5MultiIterTerm((Fts5Iter*)pIndexIter, &n);
+  assert_nc( z || n<=1 );
  *pn = n-1;
-  return &z[1];
+  return (z ? &z[1] : 0);
 }

 /*
@@ -6059,7 +6138,7 @@ static void fts5IndexIntegrityCheckSegment(
 ** error, or some other SQLite error code if another error (e.g. OOM)
 ** occurs.
 */
-int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum){
+int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum, int bUseCksum){
  int eDetail = p->pConfig->eDetail;
  u64 cksum2 = 0;                 /* Checksum based on contents of indexes */
  Fts5Buffer poslist = {0,0,0};   /* Buffer used to hold a poslist */
@@ -6120,6 +6199,7 @@ int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum){
    }else{
      poslist.n = 0;
      fts5SegiterPoslist(p, &pIter->aSeg[pIter->aFirst[1].iFirst], 0, &poslist);
+      fts5BufferAppendBlob(&p->rc, &poslist, 4, (const u8*)"\0\0\0\0");
      while( 0==sqlite3Fts5PoslistNext64(poslist.p, poslist.n, &iOff, &iPos) ){
        int iCol = FTS5_POS2COLUMN(iPos);
        int iTokOff = FTS5_POS2OFFSET(iPos);
@@ -6130,7 +6210,7 @@ int sqlite3Fts5IndexIntegrityCheck(Fts5Index *p, u64 cksum){
  fts5TestTerm(p, &term, 0, 0, cksum2, &cksum3);

  fts5MultiIterFree(pIter);
-  if( p->rc==SQLITE_OK && cksum!=cksum2 ) p->rc = FTS5_CORRUPT;
+  if( p->rc==SQLITE_OK && bUseCksum && cksum!=cksum2 ) p->rc = FTS5_CORRUPT;

  fts5StructureRelease(pStruct);
 #ifdef SQLITE_DEBUG
@@ -464,6 +464,23 @@ static void fts5SetUniqueFlag(sqlite3_index_info *pIdxInfo){
 #endif
 }

+static int fts5UsePatternMatch(
+  Fts5Config *pConfig, 
+  struct sqlite3_index_constraint *p
+){
+  assert( FTS5_PATTERN_GLOB==SQLITE_INDEX_CONSTRAINT_GLOB );
+  assert( FTS5_PATTERN_LIKE==SQLITE_INDEX_CONSTRAINT_LIKE );
+  if( pConfig->ePattern==FTS5_PATTERN_GLOB && p->op==FTS5_PATTERN_GLOB ){
+    return 1;
+  }
+  if( pConfig->ePattern==FTS5_PATTERN_LIKE 
+   && (p->op==FTS5_PATTERN_LIKE || p->op==FTS5_PATTERN_GLOB)
+  ){
+    return 1;
+  }
+  return 0;
+}
+
 /*
 ** Implementation of the xBestIndex method for FTS5 tables. Within the 
 ** WHERE constraint, it searches for the following:
@@ -493,7 +510,9 @@ static void fts5SetUniqueFlag(sqlite3_index_info *pIdxInfo){
 **
 **   Match against table column:            "m"
 **   Match against rank column:             "r"
-**   Match against other column:            "<column-number>"
+**   Match against other column:            "M<column-number>"
+**   LIKE  against other column:            "L<column-number>"
+**   GLOB  against other column:            "G<column-number>"
 **   Equality constraint against the rowid: "="
 **   A < or <= against the rowid:           "<"
 **   A > or >= against the rowid:           ">"
@@ -554,7 +573,7 @@ static int fts5BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
    return SQLITE_ERROR;
  }

-  idxStr = (char*)sqlite3_malloc(pInfo->nConstraint * 6 + 1);
+  idxStr = (char*)sqlite3_malloc(pInfo->nConstraint * 8 + 1);
  if( idxStr==0 ) return SQLITE_NOMEM;
  pInfo->idxStr = idxStr;
  pInfo->needToFreeIdxStr = 1;
@@ -578,25 +597,29 @@ static int fts5BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
          if( bSeenRank ) continue;
          idxStr[iIdxStr++] = 'r';
          bSeenRank = 1;
-        }else{
+        }else if( iCol>=0 ){
          bSeenMatch = 1;
-          idxStr[iIdxStr++] = 'm';
-          if( iCol<nCol ){
-            sqlite3_snprintf(6, &idxStr[iIdxStr], "%d", iCol);
-            idxStr += strlen(&idxStr[iIdxStr]);
-            assert( idxStr[iIdxStr]=='\0' );
-          }
+          idxStr[iIdxStr++] = 'M';
+          sqlite3_snprintf(6, &idxStr[iIdxStr], "%d", iCol);
+          idxStr += strlen(&idxStr[iIdxStr]);
+          assert( idxStr[iIdxStr]=='\0' );
        }
        pInfo->aConstraintUsage[i].argvIndex = ++iCons;
        pInfo->aConstraintUsage[i].omit = 1;
      }
-    }
-    else if( p->usable && bSeenEq==0 
-      && p->op==SQLITE_INDEX_CONSTRAINT_EQ && iCol<0 
-    ){
-      idxStr[iIdxStr++] = '=';
-      bSeenEq = 1;
-      pInfo->aConstraintUsage[i].argvIndex = ++iCons;
+    }else if( p->usable ){
+      if( iCol>=0 && iCol<nCol && fts5UsePatternMatch(pConfig, p) ){
+        assert( p->op==FTS5_PATTERN_LIKE || p->op==FTS5_PATTERN_GLOB );
+        idxStr[iIdxStr++] = p->op==FTS5_PATTERN_LIKE ? 'L' : 'G';
+        sqlite3_snprintf(6, &idxStr[iIdxStr], "%d", iCol);
+        idxStr += strlen(&idxStr[iIdxStr]);
+        pInfo->aConstraintUsage[i].argvIndex = ++iCons;
+        assert( idxStr[iIdxStr]=='\0' );
+      }else if( bSeenEq==0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ && iCol<0 ){
+        idxStr[iIdxStr++] = '=';
+        bSeenEq = 1;
+        pInfo->aConstraintUsage[i].argvIndex = ++iCons;
+      }
    }
  }

@@ -1229,19 +1252,14 @@ static int fts5FilterMethod(
      case 'r':
        pRank = apVal[i];
        break;
-      case 'm': {
+      case 'M': {
        const char *zText = (const char*)sqlite3_value_text(apVal[i]);
        if( zText==0 ) zText = "";
-
-        if( idxStr[iIdxStr]>='0' && idxStr[iIdxStr]<='9' ){
-          iCol = 0;
-          do{
-            iCol = iCol*10 + (idxStr[iIdxStr]-'0');
-            iIdxStr++;
-          }while( idxStr[iIdxStr]>='0' && idxStr[iIdxStr]<='9' );
-        }else{
-          iCol = pConfig->nCol;
-        }
+        iCol = 0;
+        do{
+          iCol = iCol*10 + (idxStr[iIdxStr]-'0');
+          iIdxStr++;
+        }while( idxStr[iIdxStr]>='0' && idxStr[iIdxStr]<='9' );

        if( zText[0]=='*' ){
          /* The user has issued a query of the form "MATCH '*...'". This
@@ -1251,7 +1269,7 @@ static int fts5FilterMethod(
          goto filter_out;
        }else{
          char **pzErr = &pTab->p.base.zErrMsg;
-          rc = sqlite3Fts5ExprNew(pConfig, iCol, zText, &pExpr, pzErr);
+          rc = sqlite3Fts5ExprNew(pConfig, 0, iCol, zText, &pExpr, pzErr);
          if( rc==SQLITE_OK ){
            rc = sqlite3Fts5ExprAnd(&pCsr->pExpr, pExpr);
            pExpr = 0;
@@ -1261,6 +1279,25 @@ static int fts5FilterMethod(

        break;
      }
+      case 'L':
+      case 'G': {
+        int bGlob = (idxStr[iIdxStr-1]=='G');
+        const char *zText = (const char*)sqlite3_value_text(apVal[i]);
+        iCol = 0;
+        do{
+          iCol = iCol*10 + (idxStr[iIdxStr]-'0');
+          iIdxStr++;
+        }while( idxStr[iIdxStr]>='0' && idxStr[iIdxStr]<='9' );
+        if( zText ){
+          rc = sqlite3Fts5ExprPattern(pConfig, bGlob, iCol, zText, &pExpr);
+        }
+        if( rc==SQLITE_OK ){
+          rc = sqlite3Fts5ExprAnd(&pCsr->pExpr, pExpr);
+          pExpr = 0;
+        }
+        if( rc!=SQLITE_OK ) goto filter_out;
+        break;
+      }
      case '=':
        pRowidEq = apVal[i];
        break;
@@ -1508,7 +1545,8 @@ static int fts5SpecialInsert(
    int nMerge = sqlite3_value_int(pVal);
    rc = sqlite3Fts5StorageMerge(pTab->pStorage, nMerge);
  }else if( 0==sqlite3_stricmp("integrity-check", zCmd) ){
-    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage);
+    int iArg = sqlite3_value_int(pVal);
+    rc = sqlite3Fts5StorageIntegrity(pTab->pStorage, iArg);
 #ifdef SQLITE_DEBUG
  }else if( 0==sqlite3_stricmp("prefix-index", zCmd) ){
    pConfig->bPrefixIndex = sqlite3_value_int(pVal);
@@ -2139,7 +2177,8 @@ static int fts5ApiPhraseFirst(
  int n;
  int rc = fts5CsrPoslist(pCsr, iPhrase, &pIter->a, &n);
  if( rc==SQLITE_OK ){
-    pIter->b = &pIter->a[n];
+    assert( pIter->a || n==0 );
+    pIter->b = (pIter->a ? &pIter->a[n] : 0);
    *piCol = 0;
    *piOff = 0;
    fts5ApiPhraseNext(pCtx, pIter, piCol, piOff);
@@ -2198,7 +2237,8 @@ static int fts5ApiPhraseFirstColumn(
      rc = sqlite3Fts5ExprPhraseCollist(pCsr->pExpr, iPhrase, &pIter->a, &n);
    }
    if( rc==SQLITE_OK ){
-      pIter->b = &pIter->a[n];
+      assert( pIter->a || n==0 );
+      pIter->b = (pIter->a ? &pIter->a[n] : 0);
      *piCol = 0;
      fts5ApiPhraseNextColumn(pCtx, pIter, piCol);
    }
@@ -2206,7 +2246,8 @@ static int fts5ApiPhraseFirstColumn(
    int n;
    rc = fts5CsrPoslist(pCsr, iPhrase, &pIter->a, &n);
    if( rc==SQLITE_OK ){
-      pIter->b = &pIter->a[n];
+      assert( pIter->a || n==0 );
+      pIter->b = (pIter->a ? &pIter->a[n] : 0);
      if( n<=0 ){
        *piCol = -1;
      }else if( pIter->a[0]==0x01 ){
@@ -2671,8 +2712,7 @@ int sqlite3Fts5GetTokenizer(
  Fts5Global *pGlobal, 
  const char **azArg,
  int nArg,
-  Fts5Tokenizer **ppTok,
-  fts5_tokenizer **ppTokApi,
+  Fts5Config *pConfig,
  char **pzErr
 ){
  Fts5TokenizerModule *pMod;
@@ -2684,16 +2724,22 @@ int sqlite3Fts5GetTokenizer(
    rc = SQLITE_ERROR;
    *pzErr = sqlite3_mprintf("no such tokenizer: %s", azArg[0]);
  }else{
-    rc = pMod->x.xCreate(pMod->pUserData, &azArg[1], (nArg?nArg-1:0), ppTok);
-    *ppTokApi = &pMod->x;
-    if( rc!=SQLITE_OK && pzErr ){
-      *pzErr = sqlite3_mprintf("error in tokenizer constructor");
+    rc = pMod->x.xCreate(
+        pMod->pUserData, (azArg?&azArg[1]:0), (nArg?nArg-1:0), &pConfig->pTok
+    );
+    pConfig->pTokApi = &pMod->x;
+    if( rc!=SQLITE_OK ){
+      if( pzErr ) *pzErr = sqlite3_mprintf("error in tokenizer constructor");
+    }else{
+      pConfig->ePattern = sqlite3Fts5TokenizerPattern(
+          pMod->x.xCreate, pConfig->pTok
+      );
    }
  }

  if( rc!=SQLITE_OK ){
-    *ppTokApi = 0;
-    *ppTok = 0;
+    pConfig->pTokApi = 0;
+    pConfig->pTok = 0;
  }

  return rc;
@@ -429,9 +429,16 @@ static int fts5StorageDeleteFromIndex(
          zText, nText, (void*)&ctx, fts5StorageInsertCallback
      );
      p->aTotalSize[iCol-1] -= (i64)ctx.szCol;
+      if( p->aTotalSize[iCol-1]<0 ){
+        rc = FTS5_CORRUPT;
+      }
    }
  }
-  p->nTotalRow--;
+  if( rc==SQLITE_OK && p->nTotalRow<1 ){
+    rc = FTS5_CORRUPT;
+  }else{
+    p->nTotalRow--;
+  }

  rc2 = sqlite3_reset(pSeek);
  if( rc==SQLITE_OK ) rc = rc2;
@@ -874,13 +881,14 @@ static int fts5StorageIntegrityCallback(
 ** some other SQLite error code if an error occurs while attempting to
 ** determine this.
 */
-int sqlite3Fts5StorageIntegrity(Fts5Storage *p){
+int sqlite3Fts5StorageIntegrity(Fts5Storage *p, int iArg){
  Fts5Config *pConfig = p->pConfig;
-  int rc;                         /* Return code */
+  int rc = SQLITE_OK;             /* Return code */
  int *aColSize;                  /* Array of size pConfig->nCol */
  i64 *aTotalSize;                /* Array of size pConfig->nCol */
  Fts5IntegrityCtx ctx;
  sqlite3_stmt *pScan;
+  int bUseCksum;

  memset(&ctx, 0, sizeof(Fts5IntegrityCtx));
  ctx.pConfig = p->pConfig;
@@ -889,83 +897,88 @@ int sqlite3Fts5StorageIntegrity(Fts5Storage *p){
  aColSize = (int*)&aTotalSize[pConfig->nCol];
  memset(aTotalSize, 0, sizeof(i64) * pConfig->nCol);

-  /* Generate the expected index checksum based on the contents of the
-  ** %_content table. This block stores the checksum in ctx.cksum. */
-  rc = fts5StorageGetStmt(p, FTS5_STMT_SCAN, &pScan, 0);
-  if( rc==SQLITE_OK ){
-    int rc2;
-    while( SQLITE_ROW==sqlite3_step(pScan) ){
-      int i;
-      ctx.iRowid = sqlite3_column_int64(pScan, 0);
-      ctx.szCol = 0;
-      if( pConfig->bColumnsize ){
-        rc = sqlite3Fts5StorageDocsize(p, ctx.iRowid, aColSize);
-      }
-      if( rc==SQLITE_OK && pConfig->eDetail==FTS5_DETAIL_NONE ){
-        rc = sqlite3Fts5TermsetNew(&ctx.pTermset);
-      }
-      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
-        if( pConfig->abUnindexed[i] ) continue;
-        ctx.iCol = i;
+  bUseCksum = (pConfig->eContent==FTS5_CONTENT_NORMAL
+           || (pConfig->eContent==FTS5_CONTENT_EXTERNAL && iArg)
+  );
+  if( bUseCksum ){
+    /* Generate the expected index checksum based on the contents of the
+    ** %_content table. This block stores the checksum in ctx.cksum. */
+    rc = fts5StorageGetStmt(p, FTS5_STMT_SCAN, &pScan, 0);
+    if( rc==SQLITE_OK ){
+      int rc2;
+      while( SQLITE_ROW==sqlite3_step(pScan) ){
+        int i;
+        ctx.iRowid = sqlite3_column_int64(pScan, 0);
        ctx.szCol = 0;
-        if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+        if( pConfig->bColumnsize ){
+          rc = sqlite3Fts5StorageDocsize(p, ctx.iRowid, aColSize);
+        }
+        if( rc==SQLITE_OK && pConfig->eDetail==FTS5_DETAIL_NONE ){
          rc = sqlite3Fts5TermsetNew(&ctx.pTermset);
        }
-        if( rc==SQLITE_OK ){
-          const char *zText = (const char*)sqlite3_column_text(pScan, i+1);
-          int nText = sqlite3_column_bytes(pScan, i+1);
-          rc = sqlite3Fts5Tokenize(pConfig, 
-              FTS5_TOKENIZE_DOCUMENT,
-              zText, nText,
-              (void*)&ctx,
-              fts5StorageIntegrityCallback
-          );
-        }
-        if( rc==SQLITE_OK && pConfig->bColumnsize && ctx.szCol!=aColSize[i] ){
-          rc = FTS5_CORRUPT;
-        }
-        aTotalSize[i] += ctx.szCol;
-        if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
-          sqlite3Fts5TermsetFree(ctx.pTermset);
-          ctx.pTermset = 0;
+        for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
+          if( pConfig->abUnindexed[i] ) continue;
+          ctx.iCol = i;
+          ctx.szCol = 0;
+          if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+            rc = sqlite3Fts5TermsetNew(&ctx.pTermset);
+          }
+          if( rc==SQLITE_OK ){
+            const char *zText = (const char*)sqlite3_column_text(pScan, i+1);
+            int nText = sqlite3_column_bytes(pScan, i+1);
+            rc = sqlite3Fts5Tokenize(pConfig, 
+                FTS5_TOKENIZE_DOCUMENT,
+                zText, nText,
+                (void*)&ctx,
+                fts5StorageIntegrityCallback
+            );
+          }
+          if( rc==SQLITE_OK && pConfig->bColumnsize && ctx.szCol!=aColSize[i] ){
+            rc = FTS5_CORRUPT;
+          }
+          aTotalSize[i] += ctx.szCol;
+          if( pConfig->eDetail==FTS5_DETAIL_COLUMNS ){
+            sqlite3Fts5TermsetFree(ctx.pTermset);
+            ctx.pTermset = 0;
+          }
        }
+        sqlite3Fts5TermsetFree(ctx.pTermset);
+        ctx.pTermset = 0;
+  
+        if( rc!=SQLITE_OK ) break;
      }
-      sqlite3Fts5TermsetFree(ctx.pTermset);
-      ctx.pTermset = 0;
-
-      if( rc!=SQLITE_OK ) break;
+      rc2 = sqlite3_reset(pScan);
+      if( rc==SQLITE_OK ) rc = rc2;
    }
-    rc2 = sqlite3_reset(pScan);
-    if( rc==SQLITE_OK ) rc = rc2;
-  }

-  /* Test that the "totals" (sometimes called "averages") record looks Ok */
-  if( rc==SQLITE_OK ){
-    int i;
-    rc = fts5StorageLoadTotals(p, 0);
-    for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
-      if( p->aTotalSize[i]!=aTotalSize[i] ) rc = FTS5_CORRUPT;
+    /* Test that the "totals" (sometimes called "averages") record looks Ok */
+    if( rc==SQLITE_OK ){
+      int i;
+      rc = fts5StorageLoadTotals(p, 0);
+      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
+        if( p->aTotalSize[i]!=aTotalSize[i] ) rc = FTS5_CORRUPT;
+      }
    }
-  }

-  /* Check that the %_docsize and %_content tables contain the expected
-  ** number of rows.  */
-  if( rc==SQLITE_OK && pConfig->eContent==FTS5_CONTENT_NORMAL ){
-    i64 nRow = 0;
-    rc = fts5StorageCount(p, "content", &nRow);
-    if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;
-  }
-  if( rc==SQLITE_OK && pConfig->bColumnsize ){
-    i64 nRow = 0;
-    rc = fts5StorageCount(p, "docsize", &nRow);
-    if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;
+    /* Check that the %_docsize and %_content tables contain the expected
+    ** number of rows.  */
+    if( rc==SQLITE_OK && pConfig->eContent==FTS5_CONTENT_NORMAL ){
+      i64 nRow = 0;
+      rc = fts5StorageCount(p, "content", &nRow);
+      if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;
+    }
+    if( rc==SQLITE_OK && pConfig->bColumnsize ){
+      i64 nRow = 0;
+      rc = fts5StorageCount(p, "docsize", &nRow);
+      if( rc==SQLITE_OK && nRow!=p->nTotalRow ) rc = FTS5_CORRUPT;
+    }
  }

  /* Pass the expected checksum down to the FTS index module. It will
  ** verify, amongst other things, that it matches the checksum generated by
  ** inspecting the index itself.  */
  if( rc==SQLITE_OK ){
-    rc = sqlite3Fts5IndexIntegrityCheck(p->pIndex, ctx.cksum);
+    rc = sqlite3Fts5IndexIntegrityCheck(p->pIndex, ctx.cksum, bUseCksum);
  }

  sqlite3_free(aTotalSize);
@@ -211,7 +211,7 @@ static int fts5tokConnectMethod(

    rc = pApi->xFindTokenizer(pApi, zModule, &pTokCtx, &pTab->tok);
    if( rc==SQLITE_OK ){
-      const char **azArg = (const char **)&azDequote[1];
+      const char **azArg = (nDequote>1 ? (const char **)&azDequote[1] : 0);
      int nArg = nDequote>0 ? nDequote-1 : 0;
      rc = pTab->tok.xCreate(pTokCtx, azArg, nArg, &pTab->pTok);
    }
@@ -1258,6 +1258,133 @@ static int fts5PorterTokenize(
  );
 }

+/**************************************************************************
+** Start of trigram implementation.
+*/
+typedef struct TrigramTokenizer TrigramTokenizer;
+struct TrigramTokenizer {
+  int bFold;                      /* True to fold to lower-case */
+};
+
+/*
+** Free a trigram tokenizer.
+*/
+static void fts5TriDelete(Fts5Tokenizer *p){
+  sqlite3_free(p);
+}
+
+/*
+** Allocate a trigram tokenizer.
+*/
+static int fts5TriCreate(
+  void *pUnused,
+  const char **azArg,
+  int nArg,
+  Fts5Tokenizer **ppOut
+){
+  int rc = SQLITE_OK;
+  TrigramTokenizer *pNew = (TrigramTokenizer*)sqlite3_malloc(sizeof(*pNew));
+  UNUSED_PARAM(pUnused);
+  if( pNew==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    int i;
+    pNew->bFold = 1;
+    for(i=0; rc==SQLITE_OK && i<nArg; i+=2){
+      const char *zArg = azArg[i+1];
+      if( 0==sqlite3_stricmp(azArg[i], "case_sensitive") ){
+        if( (zArg[0]!='0' && zArg[0]!='1') || zArg[1] ){
+          rc = SQLITE_ERROR;
+        }else{
+          pNew->bFold = (zArg[0]=='0');
+        }
+      }else{
+        rc = SQLITE_ERROR;
+      }
+    }
+    if( rc!=SQLITE_OK ){
+      fts5TriDelete((Fts5Tokenizer*)pNew);
+      pNew = 0;
+    }
+  }
+  *ppOut = (Fts5Tokenizer*)pNew;
+  return rc;
+}
+
+/*
+** Trigram tokenizer tokenize routine.
+*/
+static int fts5TriTokenize(
+  Fts5Tokenizer *pTok,
+  void *pCtx,
+  int unusedFlags,
+  const char *pText, int nText,
+  int (*xToken)(void*, int, const char*, int, int, int)
+){
+  TrigramTokenizer *p = (TrigramTokenizer*)pTok;
+  int rc = SQLITE_OK;
+  char aBuf[32];
+  const unsigned char *zIn = (const unsigned char*)pText;
+  const unsigned char *zEof = &zIn[nText];
+  u32 iCode;
+
+  UNUSED_PARAM(unusedFlags);
+  while( 1 ){
+    char *zOut = aBuf;
+    int iStart = zIn - (const unsigned char*)pText;
+    const unsigned char *zNext; 
+
+    READ_UTF8(zIn, zEof, iCode);
+    if( iCode==0 ) break;
+    zNext = zIn;
+    if( zIn<zEof ){
+      if( p->bFold ) iCode = sqlite3Fts5UnicodeFold(iCode, 0);
+      WRITE_UTF8(zOut, iCode);
+      READ_UTF8(zIn, zEof, iCode);
+      if( iCode==0 ) break;
+    }else{
+      break;
+    }
+    if( zIn<zEof ){
+      if( p->bFold ) iCode = sqlite3Fts5UnicodeFold(iCode, 0);
+      WRITE_UTF8(zOut, iCode);
+      READ_UTF8(zIn, zEof, iCode);
+      if( iCode==0 ) break;
+      if( p->bFold ) iCode = sqlite3Fts5UnicodeFold(iCode, 0);
+      WRITE_UTF8(zOut, iCode);
+    }else{
+      break;
+    }
+    rc = xToken(pCtx, 0, aBuf, zOut-aBuf, iStart, iStart + zOut-aBuf);
+    if( rc!=SQLITE_OK ) break;
+    zIn = zNext;
+  }
+
+  return rc;
+}
+
+/*
+** Argument xCreate is a pointer to a constructor function for a tokenizer.
+** pTok is a tokenizer previously created using the same method. This function
+** returns one of FTS5_PATTERN_NONE, FTS5_PATTERN_LIKE or FTS5_PATTERN_GLOB
+** indicating the style of pattern matching that the tokenizer can support.
+** In practice, this is:
+**
+**     "trigram" tokenizer, case_sensitive=1 - FTS5_PATTERN_GLOB
+**     "trigram" tokenizer, case_sensitive=0 (the default) - FTS5_PATTERN_LIKE
+**     all other tokenizers - FTS5_PATTERN_NONE
+*/
+int sqlite3Fts5TokenizerPattern(
+    int (*xCreate)(void*, const char**, int, Fts5Tokenizer**),
+    Fts5Tokenizer *pTok
+){
+  if( xCreate==fts5TriCreate ){
+    TrigramTokenizer *p = (TrigramTokenizer*)pTok;
+    return p->bFold ? FTS5_PATTERN_LIKE : FTS5_PATTERN_GLOB;
+  }
+  return FTS5_PATTERN_NONE;
+}
+
 /*
 ** Register all built-in tokenizers with FTS5.
 */
@@ -1269,6 +1396,7 @@ int sqlite3Fts5TokenizerInit(fts5_api *pApi){
    { "unicode61", {fts5UnicodeCreate, fts5UnicodeDelete, fts5UnicodeTokenize}},
    { "ascii",     {fts5AsciiCreate, fts5AsciiDelete, fts5AsciiTokenize }},
    { "porter",    {fts5PorterCreate, fts5PorterDelete, fts5PorterTokenize }},
+    { "trigram",   {fts5TriCreate, fts5TriDelete, fts5TriTokenize}},
  };
  
  int rc = SQLITE_OK;             /* Return code */
@@ -773,4 +773,6 @@ void sqlite3Fts5UnicodeAscii(u8 *aArray, u8 *aAscii){
    }
    iTbl++;
  }
+  aAscii[0] = 0;                  /* 0x00 is never a token character */
 }
+
@@ -82,5 +82,24 @@ foreach_detail_mode $::testprefix {
  } {1 {unable to use function MATCH in the requested context}}
 }

+#-------------------------------------------------------------------------
+# Confirm that the expression parser creates the same expression tree
+# for:
+#
+#     {a b} : (abc AND def)
+#    -{c d} : (abc AND def)
+#
+# Assuming that the table columns are (a, b, c, d).
+#
+do_execsql_test 5.1 {
+  SELECT fts5_expr('abcd AND cdef');
+} {{"abcd" AND "cdef"}}
+do_execsql_test 5.2 {
+  SELECT fts5_expr('{a b} : (abcd AND cdef)', 'a', 'b', 'c', 'd');
+} {{{a b} : "abcd" AND {a b} : "cdef"}}
+do_execsql_test 5.3 {
+  SELECT fts5_expr('-{c d} : (abcd AND cdef)', 'a', 'b', 'c', 'd');
+} {{{a b} : "abcd" AND {a b} : "cdef"}}
+

 finish_test
@@ -29,6 +29,8 @@ do_execsql_test 1.0 {
  INSERT INTO ttt SELECT a||a, b||b FROM ttt;   
 }

+expr srand(1)
+
 proc mutate {blob i} {
  set o [expr {$i % [string length $blob]}]
  set a [string range $blob 0 $o-1]
@@ -50,4 +50,68 @@ do_test 1.2 {
  }
 } {}

+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE test (
+      id INTEGER PRIMARY KEY,
+      name TEXT,
+      value TEXT
+  );
+  CREATE VIRTUAL TABLE test_idx USING fts5(
+      name, content=test, content_rowid=id
+  );
+}
+
+do_catchsql_test 2.1 {
+  INSERT INTO test_idx (test_idx, rowid, name) VALUES('delete', 1, 'quick');
+} {1 {database disk image is malformed}}
+
+do_catchsql_test 2.2 {
+  INSERT INTO test_idx(rowid, name) VALUES(123, 'one one one');
+  INSERT INTO test_idx (test_idx, rowid, name) VALUES('delete', 123, 'one');
+  INSERT INTO test_idx (test_idx, rowid, name) VALUES('delete', 123, 'one');
+} {1 {database disk image is malformed}}
+
+do_execsql_test 2.3 {
+  DROP TABLE test_idx;
+  CREATE VIRTUAL TABLE test_idx USING fts5(
+      name, content=test, content_rowid=id
+  );
+
+  INSERT INTO test_idx(rowid, name) VALUES(123, 'one one one');
+  INSERT INTO test_idx(rowid, name) VALUES(124, 'two two two');
+  INSERT INTO test_idx(rowid, name) VALUES(125, 'two two two');
+  INSERT INTO test_idx (test_idx, rowid, name) VALUES('delete', 123, 'one');
+  INSERT INTO test_idx (test_idx, rowid, name) VALUES('delete', 123, 'one');
+  INSERT INTO test_idx (test_idx, rowid, name) VALUES('delete', 123, 'one');
+}
+
+do_catchsql_test 2.4 {
+  SELECT rowid FROM test_idx WHERE test_idx MATCH 'two' ORDER BY rank;
+} {1 {database disk image is malformed}}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 3.0 {
+  CREATE VIRTUAL TABLE tx USING fts5(a, b, c, d, content=);
+  INSERT INTO tx(rowid, a, c) VALUES(1, 'abc def', 'a b c');
+  INSERT INTO tx(rowid, a, c) VALUES(5, 'a b c', 'a b d def');
+}
+do_execsql_test 3.1 {
+  INSERT INTO tx(tx, rowid, a, b, c, d) 
+    VALUES('delete', 5, 'a b c', NULL, 'a b d def', NULL);
+}
+do_execsql_test 3.2 {
+  INSERT INTO tx(tx) VALUES('integrity-check');
+}
+do_execsql_test 3.3 {
+  INSERT INTO tx(tx, rowid, a, b, c, d) 
+    VALUES('delete', 1, 'abc def', NULL, 'a b c', NULL);
+}
+do_execsql_test 3.4 {
+  INSERT INTO tx(tx) VALUES('integrity-check');
+}
+
 finish_test
+
@@ -14,7 +14,7 @@

 source [file join [file dirname [info script]] fts5_common.tcl]
 source $testdir/malloc_common.tcl
-set testprefix fts5faultA
+set testprefix fts5faultD

 # If SQLITE_ENABLE_FTS3 is defined, omit this file.
 ifcapable !fts5 {
@@ -0,0 +1,71 @@
+# 2016 February 2
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#*************************************************************************
+#
+# This file is focused on OOM errors.
+#
+
+source [file join [file dirname [info script]] fts5_common.tcl]
+source $testdir/malloc_common.tcl
+set testprefix fts5faultE
+
+# If SQLITE_ENABLE_FTS5 is not defined, omit this file.
+ifcapable !fts5 {
+  finish_test
+  return
+}
+
+faultsim_save_and_close
+do_faultsim_test 1 -prep {
+  faultsim_restore_and_reopen
+} -body {
+  execsql { CREATE VIRTUAL TABLE t1 USING fts5(x, y, tokenize=trigram) }
+} -test {
+  faultsim_test_result {0 {}} {1 {vtable constructor failed: t1}} 
+}
+
+reset_db
+do_execsql_test 2.0 {
+  CREATE VIRTUAL TABLE t1 USING fts5(x, y, tokenize=trigram);
+}
+
+faultsim_save_and_close
+do_faultsim_test 2 -prep {
+  faultsim_restore_and_reopen
+} -body {
+  execsql { 
+    INSERT INTO t1 VALUES('abcdefghijklmnopqrstuvwxyz', NULL);
+    SELECT count(*) FROM t1 WHERE x LIKE '%mnop%' AND t1 MATCH 'jkl';
+  }
+} -test {
+  faultsim_test_result {0 1} {1 {vtable constructor failed: t1}}
+}
+
+reset_db
+do_execsql_test 3.0 {
+  CREATE VIRTUAL TABLE t1 USING fts5(x, y, tokenize=trigram, detail=none);
+  INSERT INTO t1 VALUES('abcdefghijklmnopqrstuvwxyz', NULL);
+}
+
+faultsim_save_and_close
+do_faultsim_test 3 -prep {
+  faultsim_restore_and_reopen
+} -body {
+  execsql { 
+    SELECT count(*) FROM t1 WHERE x LIKE '%mnopqrs%' AND t1 MATCH 'abc'
+  }
+} -test {
+  faultsim_test_result {0 1} {1 {vtable constructor failed: t1}}
+}
+
+
+
+finish_test
+
@@ -112,7 +112,7 @@ foreach_detail_mode $testprefix {
  # Add a small and very large token with the same hash value to an
  # empty table. At one point this would provoke an asan error.
  #
-  do_test 2.0 {
+  do_test 1.5 {
    set big [string repeat 12345 40]
    set hash [sqlite3_fts5_token_hash 1024 $big]
    while {1} {
@@ -128,4 +128,41 @@ foreach_detail_mode $testprefix {

 } ;# foreach_detail_mode

+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.1 {
+  CREATE VIRTUAL TABLE t1 USING fts5(x);
+  INSERT INTO t1(t1, rank) VALUES('hashsize', 1024);
+  INSERT INTO t1(t1, rank) VALUES('automerge', 0);
+  INSERT INTO t1(t1, rank) VALUES('crisismerge', 1000);
+}
+
+do_execsql_test 2.2 {
+  BEGIN;
+    INSERT INTO t1 VALUES('abc def ghi');
+    SELECT count(*) FROM t1_data;
+} {2}
+
+do_execsql_test 2.3 {
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<1024
+  )
+  INSERT INTO t1 SELECT 'abc def ghi' FROM s;
+  SELECT (SELECT count(*) FROM t1_data) > 10;
+} {1}
+
+do_execsql_test 2.4 {
+  COMMIT;
+  DROP TABLE t1;
+  CREATE VIRTUAL TABLE t1 USING fts5(x);
+  INSERT INTO t1(t1, rank) VALUES('hashsize', 1024);
+  INSERT INTO t1(t1, rank) VALUES('automerge', 0);
+  INSERT INTO t1(t1, rank) VALUES('crisismerge', 1000);
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<1024
+  )
+  INSERT INTO t1 SELECT 'abc' || i || ' def' || i || ' ghi' || i FROM s;
+  SELECT (SELECT count(*) FROM t1_data) > 100;
+} {1}
+
 finish_test
@@ -273,7 +273,6 @@ do_execsql_test 9.1.2 {
  SELECT quote(x'37');
 } {X'37'}

-breakpoint
 do_execsql_test 9.2 {
  INSERT INTO vt0 VALUES (SUBSTR(x'37', 0));
 --  INSERT INTO vt0 VALUES (x'37');
@@ -282,4 +281,40 @@ do_execsql_test 9.3 {
  INSERT INTO vt0(vt0) VALUES('integrity-check');
 }

+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 10.0 {
+  CREATE TABLE t1(i INTEGER PRIMARY KEY, a, b);
+  CREATE VIRTUAL TABLE vt0 USING fts5(a, b, content=t1);
+  INSERT INTO vt0(rowid, a, b) VALUES(1, 'abc', 'def');
+}
+do_catchsql_test 10.1 {
+  INSERT INTO vt0(vt0) VALUES('integrity-check');
+} {0 {}}
+do_catchsql_test 10.2 {
+  INSERT INTO vt0(vt0, rank) VALUES('integrity-check', 0);
+} {0 {}}
+do_catchsql_test 10.3 {
+  INSERT INTO vt0(vt0, rank) VALUES('integrity-check', 1);
+} {1 {database disk image is malformed}}
+do_catchsql_test 10.3 {
+  INSERT INTO t1 VALUES(1, 'abc', 'def');
+  INSERT INTO vt0(vt0, rank) VALUES('integrity-check', 1);
+} {0 {}}
+
+do_execsql_test 10.4 {
+  CREATE VIRTUAL TABLE vt1 USING fts5(a, b, content=);
+  INSERT INTO vt1(rowid, a, b) VALUES(1, 'abc', 'def');
+}
+
+do_catchsql_test 10.5.1 {
+  INSERT INTO vt0(vt0, rank) VALUES('integrity-check', 0);
+} {0 {}}
+do_catchsql_test 10.5.2 {
+  INSERT INTO vt0(vt0, rank) VALUES('integrity-check', 1);
+} {0 {}}
+do_catchsql_test 10.5.3 {
+  INSERT INTO vt0(vt0) VALUES('integrity-check');
+} {0 {}}
+
 finish_test
@@ -31,7 +31,7 @@ do_eqp_test 1.1 {
 } {
  QUERY PLAN
  |--SCAN TABLE t1
-  `--SCAN TABLE f1 VIRTUAL TABLE INDEX 0:m
+  `--SCAN TABLE f1 VIRTUAL TABLE INDEX 0:M1
 }

 do_eqp_test 1.2 {
@@ -46,7 +46,7 @@ do_eqp_test 1.3 {
  SELECT * FROM f1 WHERE f1 MATCH ? ORDER BY ff
 } {
  QUERY PLAN
-  |--SCAN TABLE f1 VIRTUAL TABLE INDEX 0:m
+  |--SCAN TABLE f1 VIRTUAL TABLE INDEX 0:M1
  `--USE TEMP B-TREE FOR ORDER BY
 }

@@ -0,0 +1,57 @@
+# 2020 Dec 3
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file contains tests focused on prefix indexes.
+#
+
+source [file join [file dirname [info script]] fts5_common.tcl]
+set testprefix fts5prefix2
+
+# If SQLITE_ENABLE_FTS5 is defined, omit this file.
+ifcapable !fts5 {
+  finish_test
+  return
+}
+
+foreach p {3 2 1} {
+  reset_db
+    do_execsql_test 1.$p.0 "
+    CREATE VIRTUAL TABLE t1 USING fts5(xyz, prefix=$p);
+  "
+  do_execsql_test 1.$p.1 {
+    INSERT INTO t1 VALUES
+      ('May you do good and not evil.'),
+      ('May you find forgiveness for yourself and forgive others.'),
+      ('May you share freely, never taking more than you give f.');
+  }
+
+  do_execsql_test 1.$p.2 {
+    SELECT highlight(t1, 0, '[', ']') FROM t1('f*');
+  } {
+    {May you [find] [forgiveness] [for] yourself and [forgive] others.}
+    {May you share [freely], never taking more than you give [f].}
+  }
+}
+
+do_execsql_test 2.0 {
+  CREATE VIRTUAL TABLE t2 USING fts5(one, prefix=3);
+  INSERT INTO t2 VALUES('top');
+  INSERT INTO t2 VALUES('to');
+  INSERT INTO t2 VALUES('tommy');
+}
+
+do_execsql_test 2.1 {
+  SELECT * FROM t2('to*');
+} {top to tommy}
+
+
+
+finish_test
@@ -111,5 +111,40 @@ do_catchsql_test 2.1 {
  SELECT * FROM t4;
 } {1 {SQL logic error}}

+#-------------------------------------------------------------------------
+# Embedded 0x00 characters.
+#
+reset_db
+do_execsql_test 3.1.0 {
+  CREATE VIRTUAL TABLE t1 USING fts5(z);
+  CREATE VIRTUAL TABLE tt USING fts5vocab(t1, 'instance');
+  INSERT INTO t1 VALUES('abc' || char(0) || 'def');
+  SELECT * FROM tt;
+} { abc 1 z 0 def 1 z 1 }
+do_execsql_test 3.1.1 {
+  SELECT hex(z) FROM t1;
+} {61626300646566}
+do_execsql_test 3.1.2 {
+  INSERT INTO t1(t1) VALUES('integrity-check');
+} {}
+
+do_execsql_test 3.2.0 {
+  CREATE VIRTUAL TABLE t2 USING fts5(z, 
+      tokenize="unicode61 categories 'L* N* Co Cc'"
+  );
+  CREATE VIRTUAL TABLE tu USING fts5vocab(t2, 'instance');
+
+  INSERT INTO t2 VALUES('abc' || char(0) || 'def');
+  SELECT * FROM tu;
+} { abc 1 z 0 def 1 z 1 }
+
+do_execsql_test 3.2.1 {
+  SELECT hex(z) FROM t1;
+} {61626300646566}
+
+do_execsql_test 3.2.2 {
+  INSERT INTO t1(t1) VALUES('integrity-check');
+} {}
+

 finish_test
@@ -0,0 +1,201 @@
+# 2020 September 30
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#*************************************************************************
+#
+# Tests for the fts5 "trigram" tokenizer.
+#
+
+source [file join [file dirname [info script]] fts5_common.tcl]
+ifcapable !fts5 { finish_test ; return }
+set ::testprefix fts5trigram
+
+do_execsql_test 1.0 {
+  CREATE VIRTUAL TABLE t1 USING fts5(y, tokenize=trigram);
+  INSERT INTO t1 VALUES('abcdefghijklm');
+  INSERT INTO t1 VALUES('กรุงเทพมหานคร');
+}
+
+foreach {tn s res} {
+  1 abc           "(abc)defghijklm"
+  2 defgh         "abc(defgh)ijklm"
+  3 abcdefghijklm "(abcdefghijklm)"
+  4 กรุ            "(กรุ)งเทพมหานคร"
+  5 งเทพมห        "กรุ(งเทพมห)านคร"
+  6 กรุงเทพมหานคร  "(กรุงเทพมหานคร)"
+  7 Abc           "(abc)defghijklm"
+  8 deFgh         "abc(defgh)ijklm"
+  9 aBcdefGhijKlm "(abcdefghijklm)"
+} {
+  do_execsql_test 1.1.$tn {
+    SELECT highlight(t1, 0, '(', ')') FROM t1($s)
+  } $res
+}
+
+do_execsql_test 1.2.0 {
+  SELECT fts5_expr('ABCD', 'tokenize=trigram')
+} {{"abc" + "bcd"}}
+
+do_execsql_test 1.2.1 {
+  SELECT * FROM t1 WHERE y LIKE ? ESCAPE 'a'
+}
+
+foreach {tn like res} {
+  1 {%cDef%}   1
+  2 {cDef%}    {}
+  3 {%f%}      1
+  4 {%f_h%}    1
+  5 {%f_g%}    {}
+  6 {abc%klm}  1
+  7 {ABCDEFG%} 1
+  8 {%รุงเ%}    2
+} {
+  do_execsql_test 1.3.$tn {
+    SELECT rowid FROM t1 WHERE y LIKE $like
+  } $res
+}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.0 {
+  CREATE VIRTUAL TABLE t1 USING fts5(y, tokenize="trigram case_sensitive 1");
+  INSERT INTO t1 VALUES('abcdefghijklm');
+  INSERT INTO t1 VALUES('กรุงเทพมหานคร');
+}
+
+foreach {tn s res} {
+  1 abc           "(abc)defghijklm"
+  2 defgh         "abc(defgh)ijklm"
+  3 abcdefghijklm "(abcdefghijklm)"
+  4 กรุ            "(กรุ)งเทพมหานคร"
+  5 งเทพมห        "กรุ(งเทพมห)านคร"
+  6 กรุงเทพมหานคร  "(กรุงเทพมหานคร)"
+  7 Abc           ""
+  8 deFgh         ""
+  9 aBcdefGhijKlm ""
+} {
+  do_execsql_test 2.1.$tn {
+    SELECT highlight(t1, 0, '(', ')') FROM t1($s)
+  } $res
+}
+foreach {tn like res} {
+  1 {%cDef%}   1
+  2 {cDef%}    {}
+  3 {%f%}      1
+  4 {%f_h%}    1
+  5 {%f_g%}    {}
+  6 {abc%klm}  1
+  7 {ABCDEFG%} 1
+  8 {%รุงเ%}    2
+} {
+  do_execsql_test 2.2.$tn {
+    SELECT rowid FROM t1 WHERE y LIKE $like
+  } $res
+}
+foreach {tn like res} {
+  1 {*cdef*}     1
+  2 {cdef*}      {}
+  3 {*f*}        1
+  4 {*f?h*}      1
+  5 {*f?g*}      {}
+  6 {abc*klm}    1
+  7 {abcdefg*}   1
+  8 {*รุงเ*}      2
+  9 {abc[d]efg*} 1
+ 10 {abc[]d]efg*} 1
+ 11 {abc[^]d]efg*} {}
+ 12 {abc[^]XYZ]efg*} 1
+} {
+  do_execsql_test 2.3.$tn {
+    SELECT rowid FROM t1 WHERE y GLOB $like
+  } $res
+}
+
+do_execsql_test 2.3.null.1 {
+  SELECT rowid FROM t1 WHERE y LIKE NULL
+}
+
+#-------------------------------------------------------------------------
+reset_db
+do_catchsql_test 3.1 {
+  CREATE VIRTUAL TABLE ttt USING fts5(c, tokenize="trigram case_sensitive 2");
+} {1 {error in tokenizer constructor}}
+do_catchsql_test 3.2 {
+  CREATE VIRTUAL TABLE ttt USING fts5(c, tokenize="trigram case_sensitive 11");
+} {1 {error in tokenizer constructor}}
+do_catchsql_test 3.3 {
+  CREATE VIRTUAL TABLE ttt USING fts5(c, "tokenize=trigram case_sensitive 1");
+} {0 {}}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 4.0 {
+  CREATE VIRTUAL TABLE t0 USING fts5(b, tokenize = "trigram");
+}
+do_execsql_test 4.1 {
+  INSERT INTO t0 VALUES (x'000b01');
+}
+do_execsql_test 4.2 {
+  INSERT INTO t0(t0) VALUES('integrity-check');
+}
+
+#-------------------------------------------------------------------------
+reset_db
+foreach_detail_mode $::testprefix {
+  foreach {ci} {0 1} {
+    reset_db
+    do_execsql_test 5.cs=$ci.0.1 "
+      CREATE VIRTUAL TABLE t1 USING fts5(
+          y, tokenize=\"trigram case_sensitive $ci\", detail=%DETAIL%
+      );
+    "
+    do_execsql_test 5.cs=$ci.0.2 {
+      INSERT INTO t1 VALUES('abcdefghijklm');
+      INSERT INTO t1 VALUES('กรุงเทพมหานคร');
+    }
+
+    foreach {tn like res} {
+      1 {%cDef%}   1
+      2 {cDef%}    {}
+      3 {%f%}      1
+      4 {%f_h%}    1
+      5 {%f_g%}    {}
+      6 {abc%klm}  1
+      7 {ABCDEFG%} 1
+      8 {%รุงเ%}    2
+    } {
+      do_execsql_test 5.cs=$ci.1.$tn {
+        SELECT rowid FROM t1 WHERE y LIKE $like
+      } $res
+    }
+  }
+}
+
+do_execsql_test 6.0 {
+  CREATE VIRTUAL TABLE ci0 USING fts5(x, tokenize="trigram");
+  CREATE VIRTUAL TABLE ci1 USING fts5(x, tokenize="trigram case_sensitive 1");
+}
+
+# LIKE and GLOB both work with case-insensitive tokenizers. Only GLOB works
+# with case-sensitive.
+do_eqp_test 6.1 {
+  SELECT * FROM ci0 WHERE x LIKE ?
+} {VIRTUAL TABLE INDEX 0:L0}
+do_eqp_test 6.2 {
+  SELECT * FROM ci0 WHERE x GLOB ?
+} {VIRTUAL TABLE INDEX 0:G0}
+do_eqp_test 6.3 {
+  SELECT * FROM ci1 WHERE x LIKE ?
+} {{SCAN TABLE ci1 VIRTUAL TABLE INDEX 0:}}
+do_eqp_test 6.4 {
+  SELECT * FROM ci1 WHERE x GLOB ?
+} {VIRTUAL TABLE INDEX 0:G0}
+
+finish_test
+
@@ -12,6 +12,7 @@ proc process_cmdline {} {
  cmdline::process ::A $::argv {
    {fts5                 "use fts5 (this is the default)"}
    {fts4                 "use fts4"}
+    {trigram              "Use tokenize=trigram"}
    {colsize   "10 10 10" "list of column sizes"}
    {tblname   "t1"       "table name to create"}
    {detail    "full"     "Fts5 detail mode to use"}
@@ -175,6 +176,7 @@ proc create_table {} {
  set sql    "CREATE VIRTUAL TABLE IF NOT EXISTS $A(tblname) USING $A(fts) ("
  append sql [join $cols ,]
  if {$A(fts)=="fts5"} { append sql ",detail=$A(detail)" }
+  if {$A(trigram)} { append sql ",tokenize=trigram" }
  append sql ", prefix='$A(prefix)');"

  db eval $sql
@@ -116,7 +116,8 @@ SQLite. Documentation follows.
  and use it as a dynamically loadable SQLite extension. To do this
  using gcc on *nix:

-    gcc -shared icu.c `icu-config --ldflags` -o libSqliteIcu.so
+    gcc -fPIC -shared icu.c `pkg-config --libs --cflags icu-uc icu-io` \
+        -o libSqliteIcu.so

  You may need to add "-I" flags so that gcc can find sqlite3ext.h
  and sqlite3.h. The resulting shared lib, libSqliteIcu.so, may be
@@ -24,4 +24,3 @@ int sqlite3IcuInit(sqlite3 *db);
 #ifdef __cplusplus
 }  /* extern "C" */
 #endif  /* __cplusplus */
-
@@ -654,5 +654,3 @@ void test_data_3(
    testFree(zName);
  }
 }
-
-
@@ -322,5 +322,3 @@ void do_writer_crash_test(const char *zPattern, int *pRc){
  }

 }
-
-
@@ -138,6 +138,3 @@ void test_data_4(
    testFree(zName);
  }
 }
-
-
-
@@ -69,7 +69,3 @@ int do_bt(int nArg, char **azArg){
  sqlite4_buffer_clear(&buf.output);
  return 0;
 }
-
-
-
-
@@ -553,7 +553,7 @@ static int sql_begin(TestDb *pTestDb, int iLevel){
  /* If there are no transactions at all open, open a read transaction. */
  if( pDb->nOpenTrans==0 ){
    int rc = sqlite3_exec(pDb->db, 
-        "BEGIN; SELECT * FROM sqlite_master LIMIT 1;" , 0, 0, 0
+        "BEGIN; SELECT * FROM sqlite_schema LIMIT 1;" , 0, 0, 0
    );
    if( rc!=0 ) return rc;
    pDb->nOpenTrans = 1;
@@ -367,4 +367,3 @@ int test_mdb_scan(
 }

 #endif /* HAVE_MDB */
-
@@ -978,5 +978,3 @@ static int bgc_detach(BtDb *pDb){
 /*
 ** End of background checkpointer.
 *************************************************************************/
-
-
@@ -228,6 +228,10 @@ static int lsmPosixOsRemap(
    }

    p->pMap = mmap(0, iSz, PROT_READ|PROT_WRITE, MAP_SHARED, p->fd, 0);
+    if( p->pMap==MAP_FAILED ){
+      p->pMap = 0;
+      return LSM_IOERR_BKPT;
+    }
    p->nMap = iSz;
  }

@@ -413,7 +417,10 @@ static int lsmPosixOsShmMap(lsm_file *pFile, int iChunk, int sz, void **ppShm){
    p->apShm[iChunk] = mmap(0, LSM_SHM_CHUNK_SIZE, 
        PROT_READ|PROT_WRITE, MAP_SHARED, p->shmfd, iChunk*LSM_SHM_CHUNK_SIZE
    );
-    if( p->apShm[iChunk]==0 ) return LSM_IOERR_BKPT;
+    if( p->apShm[iChunk]==MAP_FAILED ){
+      p->apShm[iChunk] = 0;
+      return LSM_IOERR_BKPT;
+    }
  }

  *ppShm = p->apShm[iChunk];
@@ -14,24 +14,23 @@
 ** appended onto the end of some other file, such as an executable.
 **
 ** A special record must appear at the end of the file that identifies the
-** file as an appended database and provides an offset to page 1.  For
-** best performance page 1 should be located at a disk page boundary, though
-** that is not required.
+** file as an appended database and provides the offset to the first page
+** of the exposed content. (Or, it is the length of the content prefix.)
+** For best performance page 1 should be located at a disk page boundary,
+** though that is not required.
 **
 ** When opening a database using this VFS, the connection might treat
-** the file as an ordinary SQLite database, or it might treat is as a
-** database appended onto some other file.  Here are the rules:
+** the file as an ordinary SQLite database, or it might treat it as a
+** database appended onto some other file.  The decision is made by
+** applying the following rules in order:
 **
-**  (1)  When opening a new empty file, that file is treated as an ordinary
-**       database.
+**  (1)  An empty file is an ordinary database.
 **
-**  (2)  When opening a file that begins with the standard SQLite prefix
-**       string "SQLite format 3", that file is treated as an ordinary
-**       database.
+**  (2)  If the file ends with the appendvfs trailer string
+**       "Start-Of-SQLite3-NNNNNNNN" that file is an appended database.
 **
-**  (3)  When opening a file that ends with the appendvfs trailer string
-**       "Start-Of-SQLite3-NNNNNNNN" that file is treated as an appended
-**       database.
+**  (3)  If the file begins with the standard SQLite prefix string
+**       "SQLite format 3", that file is an ordinary database.
 **
 **  (4)  If none of the above apply and the SQLITE_OPEN_CREATE flag is
 **       set, then a new database is appended to the already existing file.
@@ -39,13 +38,13 @@
 **  (5)  Otherwise, SQLITE_CANTOPEN is returned.
 **
 ** To avoid unnecessary complications with the PENDING_BYTE, the size of
-** the file containing the database is limited to 1GB.  This VFS will refuse
-** to read or write past the 1GB mark.  This restriction might be lifted in
-** future versions.  For now, if you need a large database, then keep the
-** database in a separate file.
+** the file containing the database is limited to 1GiB. (1073741824 bytes)
+** This VFS will not read or write past the 1GiB mark.  This restriction
+** might be lifted in future versions.  For now, if you need a larger
+** database, then keep it in a separate file.
 **
-** If the file being opened is not an appended database, then this shim is
-** a pass-through into the default underlying VFS.
+** If the file being opened is a plain database (not an appended one), then
+** this shim is a pass-through into the default underlying VFS. (rule 3)
 **/
 #include "sqlite3ext.h"
 SQLITE_EXTENSION_INIT1
@@ -58,17 +57,27 @@ SQLITE_EXTENSION_INIT1
 **     123456789 123456789 12345
 **
 ** The NNNNNNNN represents a 64-bit big-endian unsigned integer which is
-** the offset to page 1.
+** the offset to page 1, and also the length of the prefix content.
 */
 #define APND_MARK_PREFIX     "Start-Of-SQLite3-"
 #define APND_MARK_PREFIX_SZ  17
-#define APND_MARK_SIZE       25
+#define APND_MARK_FOS_SZ      8
+#define APND_MARK_SIZE       (APND_MARK_PREFIX_SZ+APND_MARK_FOS_SZ)

 /*
 ** Maximum size of the combined prefix + database + append-mark.  This
 ** must be less than 0x40000000 to avoid locking issues on Windows.
 */
-#define APND_MAX_SIZE  (65536*15259)
+#define APND_MAX_SIZE  (0x40000000)
+
+/*
+** Try to align the database to an even multiple of APND_ROUNDUP bytes.
+*/
+#ifndef APND_ROUNDUP
+#define APND_ROUNDUP 4096
+#endif
+#define APND_ALIGN_MASK         ((sqlite3_int64)(APND_ROUNDUP-1))
+#define APND_START_ROUNDUP(fsz) (((fsz)+APND_ALIGN_MASK) & ~APND_ALIGN_MASK)

 /*
 ** Forward declaration of objects used by this utility
@@ -82,11 +91,45 @@ typedef struct ApndFile ApndFile;
 #define ORIGVFS(p)  ((sqlite3_vfs*)((p)->pAppData))
 #define ORIGFILE(p) ((sqlite3_file*)(((ApndFile*)(p))+1))

-/* An open file */
+/* An open appendvfs file
+**
+** An instance of this structure describes the appended database file.
+** A separate sqlite3_file object is always appended. The appended
+** sqlite3_file object (which can be accessed using ORIGFILE()) describes
+** the entire file, including the prefix, the database, and the
+** append-mark.
+**
+** The structure of an AppendVFS database is like this:
+**
+**   +-------------+---------+----------+-------------+
+**   | prefix-file | padding | database | append-mark |
+**   +-------------+---------+----------+-------------+
+**                           ^          ^
+**                           |          |
+**                         iPgOne      iMark
+**
+**
+** "prefix file" -  file onto which the database has been appended.
+** "padding"     -  zero or more bytes inserted so that "database"
+**                  starts on an APND_ROUNDUP boundary
+** "database"    -  The SQLite database file
+** "append-mark" -  The 25-byte "Start-Of-SQLite3-NNNNNNNN" that indicates
+**                  the offset from the start of prefix-file to the start
+**                  of "database".
+**
+** The size of the database is iMark - iPgOne.
+**
+** The NNNNNNNN in the "Start-Of-SQLite3-NNNNNNNN" suffix is the value
+** of iPgOne stored as a big-ending 64-bit integer.
+**
+** iMark will be the size of the underlying file minus 25 (APND_MARKSIZE).
+** Or, iMark is -1 to indicate that it has not yet been written.
+*/
 struct ApndFile {
-  sqlite3_file base;              /* IO methods */
-  sqlite3_int64 iPgOne;           /* File offset to page 1 */
-  sqlite3_int64 iMark;            /* Start of the append-mark */
+  sqlite3_file base;        /* Subclass.  MUST BE FIRST! */
+  sqlite3_int64 iPgOne;     /* Offset to the start of the database */
+  sqlite3_int64 iMark;      /* Offset of the append mark.  -1 if unwritten */
+  /* Always followed by another sqlite3_file that describes the whole file */
 };

 /*
@@ -178,8 +221,6 @@ static const sqlite3_io_methods apnd_io_methods = {
  apndUnfetch                     /* xUnfetch */
 };

-
-
 /*
 ** Close an apnd-file.
 */
@@ -197,22 +238,37 @@ static int apndRead(
  int iAmt, 
  sqlite_int64 iOfst
 ){
-  ApndFile *p = (ApndFile *)pFile;
+  ApndFile *paf = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
-  return pFile->pMethods->xRead(pFile, zBuf, iAmt, iOfst+p->iPgOne);
+  return pFile->pMethods->xRead(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
 }

 /*
-** Add the append-mark onto the end of the file.
+** Add the append-mark onto what should become the end of the file.
+*  If and only if this succeeds, internal ApndFile.iMark is updated.
+*  Parameter iWriteEnd is the appendvfs-relative offset of the new mark.
 */
-static int apndWriteMark(ApndFile *p, sqlite3_file *pFile){
-  int i;
+static int apndWriteMark(
+  ApndFile *paf,
+  sqlite3_file *pFile,
+  sqlite_int64 iWriteEnd
+){
+  sqlite_int64 iPgOne = paf->iPgOne;
  unsigned char a[APND_MARK_SIZE];
+  int i = APND_MARK_FOS_SZ;
+  int rc;
+  assert(pFile == ORIGFILE(paf));
  memcpy(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ);
-  for(i=0; i<8; i++){
-    a[APND_MARK_PREFIX_SZ+i] = (p->iPgOne >> (56 - i*8)) & 0xff;
+  while( --i >= 0 ){
+    a[APND_MARK_PREFIX_SZ+i] = (unsigned char)(iPgOne & 0xff);
+    iPgOne >>= 8;
  }
-  return pFile->pMethods->xWrite(pFile, a, APND_MARK_SIZE, p->iMark);
+  iWriteEnd += paf->iPgOne;
+  if( SQLITE_OK==(rc = pFile->pMethods->xWrite
+                  (pFile, a, APND_MARK_SIZE, iWriteEnd)) ){
+    paf->iMark = iWriteEnd;
+  }
+  return rc;
 }

 /*
@@ -224,38 +280,28 @@ static int apndWrite(
  int iAmt,
  sqlite_int64 iOfst
 ){
-  int rc;
-  ApndFile *p = (ApndFile *)pFile;
+  ApndFile *paf = (ApndFile *)pFile;
+  sqlite_int64 iWriteEnd = iOfst + iAmt;
+  if( iWriteEnd>=APND_MAX_SIZE ) return SQLITE_FULL;
  pFile = ORIGFILE(pFile);
-  if( iOfst+iAmt>=APND_MAX_SIZE ) return SQLITE_FULL;
-  rc = pFile->pMethods->xWrite(pFile, zBuf, iAmt, iOfst+p->iPgOne);
-  if( rc==SQLITE_OK &&  iOfst + iAmt + p->iPgOne > p->iMark ){
-    sqlite3_int64 sz = 0;
-    rc = pFile->pMethods->xFileSize(pFile, &sz);
-    if( rc==SQLITE_OK ){
-      p->iMark = sz - APND_MARK_SIZE;
-      if( iOfst + iAmt + p->iPgOne > p->iMark ){
-        p->iMark = p->iPgOne + iOfst + iAmt;
-        rc = apndWriteMark(p, pFile);
-      }
-    }
+  /* If append-mark is absent or will be overwritten, write it. */
+  if( paf->iMark < 0 || paf->iPgOne + iWriteEnd > paf->iMark ){
+    int rc = apndWriteMark(paf, pFile, iWriteEnd);
+    if( SQLITE_OK!=rc ) return rc;
  }
-  return rc;
+  return pFile->pMethods->xWrite(pFile, zBuf, iAmt, paf->iPgOne+iOfst);
 }

 /*
 ** Truncate an apnd-file.
 */
 static int apndTruncate(sqlite3_file *pFile, sqlite_int64 size){
-  int rc;
-  ApndFile *p = (ApndFile *)pFile;
+  ApndFile *paf = (ApndFile *)pFile;
  pFile = ORIGFILE(pFile);
-  rc = pFile->pMethods->xTruncate(pFile, size+p->iPgOne+APND_MARK_SIZE);
-  if( rc==SQLITE_OK ){
-    p->iMark = p->iPgOne+size;
-    rc = apndWriteMark(p, pFile);
-  }
-  return rc;
+  /* The append mark goes out first so truncate failure does not lose it. */
+  if( SQLITE_OK!=apndWriteMark(paf, pFile, size) ) return SQLITE_IOERR;
+  /* Truncate underlying file just past append mark */
+  return pFile->pMethods->xTruncate(pFile, paf->iMark+APND_MARK_SIZE);
 }

 /*
@@ -268,16 +314,12 @@ static int apndSync(sqlite3_file *pFile, int flags){

 /*
 ** Return the current file-size of an apnd-file.
+** If the append mark is not yet there, the file-size is 0.
 */
 static int apndFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
-  ApndFile *p = (ApndFile *)pFile;
-  int rc;
-  pFile = ORIGFILE(p);
-  rc = pFile->pMethods->xFileSize(pFile, pSize);
-  if( rc==SQLITE_OK && p->iPgOne ){
-    *pSize -= p->iPgOne + APND_MARK_SIZE;
-  }
-  return rc;
+  ApndFile *paf = (ApndFile *)pFile;
+  *pSize = ( paf->iMark >= 0 )? (paf->iMark - paf->iPgOne) : 0;
+  return SQLITE_OK;
 }

 /*
@@ -308,12 +350,13 @@ static int apndCheckReservedLock(sqlite3_file *pFile, int *pResOut){
 ** File control method. For custom operations on an apnd-file.
 */
 static int apndFileControl(sqlite3_file *pFile, int op, void *pArg){
-  ApndFile *p = (ApndFile *)pFile;
+  ApndFile *paf = (ApndFile *)pFile;
  int rc;
  pFile = ORIGFILE(pFile);
+  if( op==SQLITE_FCNTL_SIZE_HINT ) *(sqlite3_int64*)pArg += paf->iPgOne;
  rc = pFile->pMethods->xFileControl(pFile, op, pArg);
  if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){
-    *(char**)pArg = sqlite3_mprintf("apnd(%lld)/%z", p->iPgOne, *(char**)pArg);
+    *(char**)pArg = sqlite3_mprintf("apnd(%lld)/%z", paf->iPgOne,*(char**)pArg);
  }
  return rc;
 }
@@ -372,6 +415,9 @@ static int apndFetch(
  void **pp
 ){
  ApndFile *p = (ApndFile *)pFile;
+  if( p->iMark < 0 || iOfst+iAmt > p->iMark ){
+    return SQLITE_IOERR; /* Cannot read what is not yet there. */
+  }
  pFile = ORIGFILE(pFile);
  return pFile->pMethods->xFetch(pFile, iOfst+p->iPgOne, iAmt, pp);
 }
@@ -383,95 +429,153 @@ static int apndUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
  return pFile->pMethods->xUnfetch(pFile, iOfst+p->iPgOne, pPage);
 }

-/*
-** Check to see if the file is an ordinary SQLite database file.
-*/
-static int apndIsOrdinaryDatabaseFile(sqlite3_int64 sz, sqlite3_file *pFile){
-  int rc;
-  char zHdr[16];
-  static const char aSqliteHdr[] = "SQLite format 3";
-  if( sz<512 ) return 0;
-  rc = pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), 0);
-  if( rc ) return 0;
-  return memcmp(zHdr, aSqliteHdr, sizeof(zHdr))==0;
-}
-
 /*
 ** Try to read the append-mark off the end of a file.  Return the
-** start of the appended database if the append-mark is present.  If
-** there is no append-mark, return -1;
+** start of the appended database if the append-mark is present.
+** If there is no valid append-mark, return -1;
+**
+** An append-mark is only valid if the NNNNNNNN start-of-database offset
+** indicates that the appended database contains at least one page.  The
+** start-of-database value must be a multiple of 512.
 */
 static sqlite3_int64 apndReadMark(sqlite3_int64 sz, sqlite3_file *pFile){
  int rc, i;
  sqlite3_int64 iMark;
+  int msbs = 8 * (APND_MARK_FOS_SZ-1);
  unsigned char a[APND_MARK_SIZE];

-  if( sz<=APND_MARK_SIZE ) return -1;
+  if( APND_MARK_SIZE!=(sz & 0x1ff) ) return -1;
  rc = pFile->pMethods->xRead(pFile, a, APND_MARK_SIZE, sz-APND_MARK_SIZE);
  if( rc ) return -1;
  if( memcmp(a, APND_MARK_PREFIX, APND_MARK_PREFIX_SZ)!=0 ) return -1;
-  iMark = ((sqlite3_int64)(a[APND_MARK_PREFIX_SZ]&0x7f))<<56;
-  for(i=1; i<8; i++){    
-    iMark += (sqlite3_int64)a[APND_MARK_PREFIX_SZ+i]<<(56-8*i);
+  iMark = ((sqlite3_int64)(a[APND_MARK_PREFIX_SZ] & 0x7f)) << msbs;
+  for(i=1; i<8; i++){
+    msbs -= 8;
+    iMark |= (sqlite3_int64)a[APND_MARK_PREFIX_SZ+i]<<msbs;
  }
+  if( iMark > (sz - APND_MARK_SIZE - 512) ) return -1;
+  if( iMark & 0x1ff ) return -1;
  return iMark;
 }

+static const char apvfsSqliteHdr[] = "SQLite format 3";
+/*
+** Check to see if the file is an appendvfs SQLite database file.
+** Return true iff it is such. Parameter sz is the file's size.
+*/
+static int apndIsAppendvfsDatabase(sqlite3_int64 sz, sqlite3_file *pFile){
+  int rc;
+  char zHdr[16];
+  sqlite3_int64 iMark = apndReadMark(sz, pFile);
+  if( iMark>=0 ){
+    /* If file has the correct end-marker, the expected odd size, and the
+    ** SQLite DB type marker where the end-marker puts it, then it
+    ** is an appendvfs database.
+    */
+    rc = pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), iMark);
+    if( SQLITE_OK==rc
+     && memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))==0
+     && (sz & 0x1ff) == APND_MARK_SIZE
+     && sz>=512+APND_MARK_SIZE
+    ){
+      return 1; /* It's an appendvfs database */
+    }
+  }
+  return 0;
+}
+
+/*
+** Check to see if the file is an ordinary SQLite database file.
+** Return true iff so. Parameter sz is the file's size.
+*/
+static int apndIsOrdinaryDatabaseFile(sqlite3_int64 sz, sqlite3_file *pFile){
+  char zHdr[16];
+  if( apndIsAppendvfsDatabase(sz, pFile) /* rule 2 */
+   || (sz & 0x1ff) != 0
+   || SQLITE_OK!=pFile->pMethods->xRead(pFile, zHdr, sizeof(zHdr), 0)
+   || memcmp(zHdr, apvfsSqliteHdr, sizeof(zHdr))!=0
+  ){
+    return 0;
+  }else{
+    return 1;
+  }
+}
+
 /*
 ** Open an apnd file handle.
 */
 static int apndOpen(
-  sqlite3_vfs *pVfs,
+  sqlite3_vfs *pApndVfs,
  const char *zName,
  sqlite3_file *pFile,
  int flags,
  int *pOutFlags
 ){
-  ApndFile *p;
-  sqlite3_file *pSubFile;
-  sqlite3_vfs *pSubVfs;
+  ApndFile *pApndFile = (ApndFile*)pFile;
+  sqlite3_file *pBaseFile = ORIGFILE(pFile);
+  sqlite3_vfs *pBaseVfs = ORIGVFS(pApndVfs);
  int rc;
-  sqlite3_int64 sz;
-  pSubVfs = ORIGVFS(pVfs);
+  sqlite3_int64 sz = 0;
  if( (flags & SQLITE_OPEN_MAIN_DB)==0 ){
-    return pSubVfs->xOpen(pSubVfs, zName, pFile, flags, pOutFlags);
+    /* The appendvfs is not to be used for transient or temporary databases.
+    ** Just use the base VFS open to initialize the given file object and
+    ** open the underlying file. (Appendvfs is then unused for this file.)
+    */
+    return pBaseVfs->xOpen(pBaseVfs, zName, pFile, flags, pOutFlags);
+  }
+  memset(pApndFile, 0, sizeof(ApndFile));
+  pFile->pMethods = &apnd_io_methods;
+  pApndFile->iMark = -1;    /* Append mark not yet written */
+
+  rc = pBaseVfs->xOpen(pBaseVfs, zName, pBaseFile, flags, pOutFlags);
+  if( rc==SQLITE_OK ){
+    rc = pBaseFile->pMethods->xFileSize(pBaseFile, &sz);
  }
-  p = (ApndFile*)pFile;
-  memset(p, 0, sizeof(*p));
-  pSubFile = ORIGFILE(pFile);
-  p->base.pMethods = &apnd_io_methods;
-  rc = pSubVfs->xOpen(pSubVfs, zName, pSubFile, flags, pOutFlags);
-  if( rc ) goto apnd_open_done;
-  rc = pSubFile->pMethods->xFileSize(pSubFile, &sz);
  if( rc ){
-    pSubFile->pMethods->xClose(pSubFile);
-    goto apnd_open_done;
+    pBaseFile->pMethods->xClose(pBaseFile);
+    pFile->pMethods = 0;
+    return rc;
  }
-  if( apndIsOrdinaryDatabaseFile(sz, pSubFile) ){
-    memmove(pFile, pSubFile, pSubVfs->szOsFile);
+  if( apndIsOrdinaryDatabaseFile(sz, pBaseFile) ){
+    /* The file being opened appears to be just an ordinary DB. Copy
+    ** the base dispatch-table so this instance mimics the base VFS. 
+    */
+    memmove(pApndFile, pBaseFile, pBaseVfs->szOsFile);
    return SQLITE_OK;
  }
-  p->iMark = 0;
-  p->iPgOne = apndReadMark(sz, pFile);
-  if( p->iPgOne>0 ){
+  pApndFile->iPgOne = apndReadMark(sz, pFile);
+  if( pApndFile->iPgOne>=0 ){
+    pApndFile->iMark = sz - APND_MARK_SIZE; /* Append mark found */
    return SQLITE_OK;
  }
  if( (flags & SQLITE_OPEN_CREATE)==0 ){
-    pSubFile->pMethods->xClose(pSubFile);
+    pBaseFile->pMethods->xClose(pBaseFile);
    rc = SQLITE_CANTOPEN;
+    pFile->pMethods = 0;
+  }else{
+    /* Round newly added appendvfs location to #define'd page boundary. 
+    ** Note that nothing has yet been written to the underlying file.
+    ** The append mark will be written along with first content write.
+    ** Until then, paf->iMark value indicates it is not yet written.
+    */
+    pApndFile->iPgOne = APND_START_ROUNDUP(sz);
  }
-  p->iPgOne = (sz+0xfff) & ~(sqlite3_int64)0xfff;
-apnd_open_done:
-  if( rc ) pFile->pMethods = 0;
  return rc;
 }

+/*
+** Delete an apnd file.
+** For an appendvfs, this could mean delete the appendvfs portion,
+** leaving the appendee as it was before it gained an appendvfs.
+** For now, this code deletes the underlying file too.
+*/
+static int apndDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync);
+}
+
 /*
 ** All other VFS methods are pass-thrus.
 */
-static int apndDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
-  return ORIGVFS(pVfs)->xDelete(ORIGVFS(pVfs), zPath, dirSync);
-}
 static int apndAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
@@ -21,7 +21,7 @@
 **    name TEXT,                   -- Name of table or index for this btree.
 **    tbl_name TEXT,               -- Associated table
 **    rootpage INT,                -- The root page of the btree
-**    sql TEXT,                    -- SQL for this btree - from sqlite_master
+**    sql TEXT,                    -- SQL for this btree - from sqlite_schema
 **    hasRowid BOOLEAN,            -- True if the btree has a rowid
 **    nEntry INT,                  -- Estimated number of entries
 **    nPage INT,                   -- Estimated number of pages
@@ -30,9 +30,9 @@
 **    zSchema TEXT HIDDEN          -- The schema to which this btree belongs
 ** );
 **
-** The first 5 fields are taken directly from the sqlite_master table.
+** The first 5 fields are taken directly from the sqlite_schema table.
 ** Considering only the first 5 fields, the only difference between 
-** this virtual table and the sqlite_master table is that this virtual
+** this virtual table and the sqlite_schema table is that this virtual
 ** table omits all entries that have a 0 or NULL rowid - in other words
 ** it omits triggers and views.
 **
@@ -88,7 +88,7 @@ typedef struct BinfoCursor BinfoCursor;
 /* A cursor for the sqlite_btreeinfo table */
 struct BinfoCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
-  sqlite3_stmt *pStmt;            /* Query against sqlite_master */
+  sqlite3_stmt *pStmt;            /* Query against sqlite_schema */
  int rc;                         /* Result of previous sqlite_step() call */
  int hasRowid;                   /* hasRowid value.  Negative if unknown. */
  sqlite3_int64 nEntry;           /* nEntry value */
@@ -242,10 +242,10 @@ static int binfoFilter(
    pCsr->zSchema = sqlite3_mprintf("main");
  }
  zSql = sqlite3_mprintf(
-      "SELECT 0, 'table','sqlite_master','sqlite_master',1,NULL "
+      "SELECT 0, 'table','sqlite_schema','sqlite_schema',1,NULL "
      "UNION ALL "
      "SELECT rowid, type, name, tbl_name, rootpage, sql"
-      " FROM \"%w\".sqlite_master WHERE rootpage>=1",
+      " FROM \"%w\".sqlite_schema WHERE rootpage>=1",
       pCsr->zSchema);
  sqlite3_finalize(pCsr->pStmt);
  pCsr->pStmt = 0;
@@ -57,21 +57,32 @@ SQLITE_EXTENSION_INIT1
 #include <assert.h>
 #include <string.h>

+/* Allowed values for the mFlags parameter to sqlite3_carray_bind().
+** Must exactly match the definitions in carray.h.
+*/
+#define CARRAY_INT32     0      /* Data is 32-bit signed integers */
+#define CARRAY_INT64     1      /* Data is 64-bit signed integers */
+#define CARRAY_DOUBLE    2      /* Data is doubles */
+#define CARRAY_TEXT      3      /* Data is char* */
+
 #ifndef SQLITE_OMIT_VIRTUALTABLE

 /*
-** Allowed datatypes
-*/
-#define CARRAY_INT32    0
-#define CARRAY_INT64    1
-#define CARRAY_DOUBLE   2
-#define CARRAY_TEXT     3
-
-/*
-** Names of types
+** Names of allowed datatypes
 */
 static const char *azType[] = { "int32", "int64", "double", "char*" };

+/*
+** Structure used to hold the sqlite3_carray_bind() information
+*/
+typedef struct carray_bind carray_bind;
+struct carray_bind {
+  void *aData;                /* The data */
+  int nData;                  /* Number of elements */
+  int mFlags;                 /* Control flags */
+  void (*xDel)(void*);        /* Destructor for aData */
+};
+

 /* carray_cursor is a subclass of sqlite3_vtab_cursor which will
 ** serve as the underlying representation of a cursor that scans
@@ -239,28 +250,39 @@ static int carrayFilter(
  int argc, sqlite3_value **argv
 ){
  carray_cursor *pCur = (carray_cursor *)pVtabCursor;
-  if( idxNum ){
-    pCur->pPtr = sqlite3_value_pointer(argv[0], "carray");
-    pCur->iCnt = pCur->pPtr ? sqlite3_value_int64(argv[1]) : 0;
-    if( idxNum<3 ){
-      pCur->eType = CARRAY_INT32;
-    }else{
-      unsigned char i;
-      const char *zType = (const char*)sqlite3_value_text(argv[2]);
-      for(i=0; i<sizeof(azType)/sizeof(azType[0]); i++){
-        if( sqlite3_stricmp(zType, azType[i])==0 ) break;
-      }
-      if( i>=sizeof(azType)/sizeof(azType[0]) ){
-        pVtabCursor->pVtab->zErrMsg = sqlite3_mprintf(
-          "unknown datatype: %Q", zType);
-        return SQLITE_ERROR;
-      }else{
-        pCur->eType = i;
-      }
+  pCur->pPtr = 0;
+  pCur->iCnt = 0;
+  switch( idxNum ){
+    case 1: {
+      carray_bind *pBind = sqlite3_value_pointer(argv[0], "carray-bind");
+      if( pBind==0 ) break;
+      pCur->pPtr = pBind->aData;
+      pCur->iCnt = pBind->nData;
+      pCur->eType = pBind->mFlags & 0x03;
+      break;
+    }
+    case 2:
+    case 3: {
+      pCur->pPtr = sqlite3_value_pointer(argv[0], "carray");
+      pCur->iCnt = pCur->pPtr ? sqlite3_value_int64(argv[1]) : 0;
+      if( idxNum<3 ){
+        pCur->eType = CARRAY_INT32;
+      }else{
+        unsigned char i;
+        const char *zType = (const char*)sqlite3_value_text(argv[2]);
+        for(i=0; i<sizeof(azType)/sizeof(azType[0]); i++){
+          if( sqlite3_stricmp(zType, azType[i])==0 ) break;
+        }
+        if( i>=sizeof(azType)/sizeof(azType[0]) ){
+          pVtabCursor->pVtab->zErrMsg = sqlite3_mprintf(
+            "unknown datatype: %Q", zType);
+          return SQLITE_ERROR;
+        }else{
+          pCur->eType = i;
+        }
+      }
+      break;
    }
-  }else{
-    pCur->pPtr = 0;
-    pCur->iCnt = 0;
  }
  pCur->iRowid = 1;
  return SQLITE_OK;
@@ -275,9 +297,16 @@ static int carrayFilter(
 ** In this implementation idxNum is used to represent the
 ** query plan.  idxStr is unused.
 **
-** idxNum is 2 if the pointer= and count= constraints exist,
-** 3 if the ctype= constraint also exists, and is 0 otherwise.
-** If idxNum is 0, then carray becomes an empty table.
+** idxNum is:
+**
+**    1    If only the pointer= constraint exists.  In this case, the
+**         parameter must be bound using sqlite3_carray_bind().
+**
+**    2    if the pointer= and count= constraints exist.
+**
+**    3    if the ctype= constraint also exists.
+**
+** idxNum is 0 otherwise and carray becomes an empty table.
 */
 static int carrayBestIndex(
  sqlite3_vtab *tab,
@@ -305,18 +334,21 @@ static int carrayBestIndex(
        break;
    }
  }
-  if( ptrIdx>=0 && cntIdx>=0 ){
+  if( ptrIdx>=0 ){
    pIdxInfo->aConstraintUsage[ptrIdx].argvIndex = 1;
    pIdxInfo->aConstraintUsage[ptrIdx].omit = 1;
-    pIdxInfo->aConstraintUsage[cntIdx].argvIndex = 2;
-    pIdxInfo->aConstraintUsage[cntIdx].omit = 1;
    pIdxInfo->estimatedCost = (double)1;
    pIdxInfo->estimatedRows = 100;
-    pIdxInfo->idxNum = 2;
-    if( ctypeIdx>=0 ){
-      pIdxInfo->aConstraintUsage[ctypeIdx].argvIndex = 3;
-      pIdxInfo->aConstraintUsage[ctypeIdx].omit = 1;
-      pIdxInfo->idxNum = 3;
+    pIdxInfo->idxNum = 1;
+    if( cntIdx>=0 ){
+      pIdxInfo->aConstraintUsage[cntIdx].argvIndex = 2;
+      pIdxInfo->aConstraintUsage[cntIdx].omit = 1;
+      pIdxInfo->idxNum = 2;
+      if( ctypeIdx>=0 ){
+        pIdxInfo->aConstraintUsage[ctypeIdx].argvIndex = 3;
+        pIdxInfo->aConstraintUsage[ctypeIdx].omit = 1;
+        pIdxInfo->idxNum = 3;
+      }
    }
  }else{
    pIdxInfo->estimatedCost = (double)2147483647;
@@ -353,6 +385,89 @@ static sqlite3_module carrayModule = {
  0,                         /* xRename */
 };

+/*
+** Destructor for the carray_bind object
+*/
+static void carrayBindDel(void *pPtr){
+  carray_bind *p = (carray_bind*)pPtr;
+  if( p->xDel!=SQLITE_STATIC ){
+     p->xDel(p->aData);
+  }
+  sqlite3_free(p);
+}
+
+/*
+** Invoke this interface in order to bind to the single-argument
+** version of CARRAY().
+*/
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_carray_bind(
+  sqlite3_stmt *pStmt,
+  int idx,
+  void *aData,
+  int nData,
+  int mFlags,
+  void (*xDestroy)(void*)
+){
+  carray_bind *pNew;
+  int i;
+  pNew = sqlite3_malloc64(sizeof(*pNew));
+  if( pNew==0 ){
+    if( xDestroy!=SQLITE_STATIC && xDestroy!=SQLITE_TRANSIENT ){
+      xDestroy(aData);
+    }
+    return SQLITE_NOMEM;
+  }
+  pNew->nData = nData;
+  pNew->mFlags = mFlags;
+  if( xDestroy==SQLITE_TRANSIENT ){
+    sqlite3_int64 sz = nData;
+    switch( mFlags & 0x03 ){
+      case CARRAY_INT32:   sz *= 4;              break;
+      case CARRAY_INT64:   sz *= 8;              break;
+      case CARRAY_DOUBLE:  sz *= 8;              break;
+      case CARRAY_TEXT:    sz *= sizeof(char*);  break;
+    }
+    if( (mFlags & 0x03)==CARRAY_TEXT ){
+      for(i=0; i<nData; i++){
+        const char *z = ((char**)aData)[i];
+        if( z ) sz += strlen(z) + 1;
+      }
+    } 
+    pNew->aData = sqlite3_malloc64( sz );
+    if( pNew->aData==0 ){
+      sqlite3_free(pNew);
+      return SQLITE_NOMEM;
+    }
+    if( (mFlags & 0x03)==CARRAY_TEXT ){
+      char **az = (char**)pNew->aData;
+      char *z = (char*)&az[nData];
+      for(i=0; i<nData; i++){
+        const char *zData = ((char**)aData)[i];
+        sqlite3_int64 n;
+        if( zData==0 ){
+          az[i] = 0;
+          continue;
+        }
+        az[i] = z;
+        n = strlen(zData);
+        memcpy(z, zData, n+1);
+        z += n+1;
+      }
+    }else{
+      memcpy(pNew->aData, aData, sz*nData);
+    }
+    pNew->xDel = sqlite3_free;
+  }else{
+    pNew->aData = aData;
+    pNew->xDel = xDestroy;
+  }
+  return sqlite3_bind_pointer(pStmt, idx, pNew, "carray-bind", carrayBindDel);
+}
+
+
 /*
 ** For testing purpose in the TCL test harness, we need a method for
 ** setting the pointer value.  The inttoptr(X) SQL function accomplishes
@@ -0,0 +1,23 @@
+/*
+** Interface definitions for the CARRAY table-valued function
+** extension.
+*/
+
+/* Use this interface to bind an array to the single-argument version
+** of CARRAY().
+*/
+int sqlite3_carray_bind(
+  sqlite3_stmt *pStmt,        /* Statement to be bound */
+  int i,                      /* Parameter index */
+  void *aData,                /* Pointer to array data */
+  int nData,                  /* Number of data elements */
+  int mFlags,                 /* CARRAY flags */
+  void (*xDel)(void*)         /* Destructgor for aData*/
+);
+
+/* Allowed values for the mFlags parameter to sqlite3_carray_bind().
+*/
+#define CARRAY_INT32     0    /* Data is 32-bit signed integers */
+#define CARRAY_INT64     1    /* Data is 64-bit signed integers */
+#define CARRAY_DOUBLE    2    /* Data is doubles */
+#define CARRAY_TEXT      3    /* Data is char* */
@@ -54,11 +54,11 @@
 ** statically linked against the application, initialize it using
 ** a single API call as follows:
 **
-**     sqlite3_cksumvfs_init();
+**     sqlite3_register_cksumvfs();
 **
 ** Cksumvfs is a VFS Shim. When loaded, "cksmvfs" becomes the new
 ** default VFS and it uses the prior default VFS as the next VFS
-** down in the stack.  This is normally what you want.  However, it
+** down in the stack.  This is normally what you want.  However, in
 ** complex situations where multiple VFS shims are being loaded,
 ** it might be important to ensure that cksumvfs is loaded in the
 ** correct order so that it sequences itself into the default VFS
@@ -79,7 +79,7 @@
 ** the reserve-bytes value to 8 by runing:
 **
 **    int n = 8;
-**    sqlite3_file_control(db, 0, SQLITE_FCNTL_RESERVED_BYTES, &n);
+**    sqlite3_file_control(db, 0, SQLITE_FCNTL_RESERVE_BYTES, &n);
 **
 ** If you do this immediately after creating a new database file,
 ** before anything else has been written into the file, then that
@@ -157,6 +157,9 @@
 ** value at offset 20 the SQLite database header is exactly 8.  If
 ** the reserved-space value is not 8, this module is a no-op.
 */
+#if defined(SQLITE_AMALGAMATION) && !defined(SQLITE_CKSUMVFS_STATIC)
+# define SQLITE_CKSUMVFS_STATIC
+#endif
 #ifdef SQLITE_CKSUMVFS_STATIC
 # include "sqlite3.h"
 #else
@@ -176,7 +179,7 @@ typedef struct CksmFile CksmFile;
 /*
 ** Useful datatype abbreviations
 */
-#if !defined(SQLITE_CORE)
+#if !defined(SQLITE_AMALGAMATION)
  typedef unsigned char u8;
  typedef unsigned int u32;
 #endif
@@ -353,6 +356,41 @@ static void cksmVerifyFunc(
  sqlite3_result_int(context, memcmp(data+nByte-8,cksum,8)==0);
 }

+#ifdef SQLITE_CKSUMVFS_INIT_FUNCNAME
+/*
+** SQL function:    initialize_cksumvfs(SCHEMANAME)
+**
+** This SQL functions (whose name is actually determined at compile-time
+** by the value of the SQLITE_CKSUMVFS_INIT_FUNCNAME macro) invokes:
+**
+**   sqlite3_file_control(db, SCHEMANAME, SQLITE_FCNTL_RESERVE_BYTE, &n);
+**
+** In order to set the reserve bytes value to 8, so that cksumvfs will
+** operation.  This feature is provided (if and only if the
+** SQLITE_CKSUMVFS_INIT_FUNCNAME compile-time option is set to a string
+** which is the name of the SQL function) so as to provide the ability
+** to invoke the file-control in programming languages that lack
+** direct access to the sqlite3_file_control() interface (ex: Java).
+**
+** This interface is undocumented, apart from this comment.  Usage
+** example:
+**
+**    1.  Compile with -DSQLITE_CKSUMVFS_INIT_FUNCNAME="ckvfs_init"
+**    2.  Run:  "SELECT cksum_init('main'); VACUUM;"
+*/
+static void cksmInitFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  int nByte = 8;
+  const char *zSchemaName = (const char*)sqlite3_value_text(argv[0]);
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  sqlite3_file_control(db, zSchemaName, SQLITE_FCNTL_RESERVE_BYTES, &nByte);
+  /* Return NULL */
+}
+#endif /* SQLITE_CKSUMBFS_INIT_FUNCNAME */
+
 /*
 ** Close a cksm-file.
 */
@@ -395,7 +433,9 @@ static int cksmRead(
  pFile = ORIGFILE(pFile);
  rc = pFile->pMethods->xRead(pFile, zBuf, iAmt, iOfst);
  if( rc==SQLITE_OK ){
-    if( iOfst==0 && iAmt>=100 && memcmp(zBuf,"SQLite format 3",16)==0 ){
+    if( iOfst==0 && iAmt>=100 && (
+          memcmp(zBuf,"SQLite format 3",16)==0 || memcmp(zBuf,"ZV-",3)==0 
+    )){
      u8 *d = (u8*)zBuf;
      char hasCorrectReserveSize = (d[20]==8);
      cksmSetFlags(p, hasCorrectReserveSize);
@@ -434,7 +474,9 @@ static int cksmWrite(
 ){
  CksmFile *p = (CksmFile *)pFile;
  pFile = ORIGFILE(pFile);
-  if( iOfst==0 && iAmt>=100 && memcmp(zBuf,"SQLite format 3",16)==0 ){
+  if( iOfst==0 && iAmt>=100 && (
+        memcmp(zBuf,"SQLite format 3",16)==0 || memcmp(zBuf,"ZV-",3)==0 
+  )){
    u8 *d = (u8*)zBuf;
    char hasCorrectReserveSize = (d[20]==8);
    cksmSetFlags(p, hasCorrectReserveSize);
@@ -604,13 +646,20 @@ static int cksmFetch(
    return SQLITE_OK;
  }
  pFile = ORIGFILE(pFile);
-  return pFile->pMethods->xFetch(pFile, iOfst, iAmt, pp);
+  if( pFile->pMethods->iVersion>2 && pFile->pMethods->xFetch ){
+    return pFile->pMethods->xFetch(pFile, iOfst, iAmt, pp);
+  }
+  *pp = 0;
+  return SQLITE_OK;
 }

 /* Release a memory-mapped page */
 static int cksmUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *pPage){
  pFile = ORIGFILE(pFile);
-  return pFile->pMethods->xUnfetch(pFile, iOfst, pPage);
+  if( pFile->pMethods->iVersion>2 && pFile->pMethods->xUnfetch ){
+    return pFile->pMethods->xUnfetch(pFile, iOfst, pPage);
+  }
+  return SQLITE_OK;
 }

 /*
@@ -634,7 +683,7 @@ static int cksmOpen(
  p = (CksmFile*)pFile;
  memset(p, 0, sizeof(*p));
  pSubFile = ORIGFILE(pFile);
-  p->base.pMethods = &cksm_io_methods;
+  pFile->pMethods = &cksm_io_methods;
  rc = pSubVfs->xOpen(pSubVfs, zName, pSubFile, flags, pOutFlags);
  if( rc ) goto cksm_open_done;
  if( flags & SQLITE_OPEN_WAL ){
@@ -701,7 +750,17 @@ static int cksmGetLastError(sqlite3_vfs *pVfs, int a, char *b){
  return ORIGVFS(pVfs)->xGetLastError(ORIGVFS(pVfs), a, b);
 }
 static int cksmCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
-  return ORIGVFS(pVfs)->xCurrentTimeInt64(ORIGVFS(pVfs), p);
+  sqlite3_vfs *pOrig = ORIGVFS(pVfs);
+  int rc;
+  assert( pOrig->iVersion>=2 );
+  if( pOrig->xCurrentTimeInt64 ){
+    rc = pOrig->xCurrentTimeInt64(pOrig, p);
+  }else{
+    double r;
+    rc = pOrig->xCurrentTime(pOrig, &r);
+    *p = (sqlite3_int64)(r*86400000.0);
+  }
+  return rc;
 }
 static int cksmSetSystemCall(
  sqlite3_vfs *pVfs,
@@ -732,6 +791,11 @@ static int cksmRegisterFunc(
  rc = sqlite3_create_function(db, "verify_checksum", 1,
                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
                   0, cksmVerifyFunc, 0, 0);
+#ifdef SQLITE_CKSUMVFS_INIT_FUNCNAME
+  (void)sqlite3_create_function(db, SQLITE_CKSUMVFS_INIT_FUNCNAME, 1,
+                   SQLITE_UTF8|SQLITE_DIRECTONLY,
+                   0, cksmInitFunc, 0, 0);
+#endif
  return rc;
 }

@@ -743,7 +807,7 @@ static int cksmRegisterFunc(
 static int cksmRegisterVfs(void){
  int rc = SQLITE_OK;
  sqlite3_vfs *pOrig;
-  if( sqlite3_vfs_find("cksum")!=0 ) return SQLITE_OK;
+  if( sqlite3_vfs_find("cksmvfs")!=0 ) return SQLITE_OK;
  pOrig = sqlite3_vfs_find(0);
  cksm_vfs.iVersion = pOrig->iVersion;
  cksm_vfs.pAppData = pOrig;
@@ -763,6 +827,13 @@ int sqlite3_register_cksumvfs(const char *NotUsed){
  (void)NotUsed;
  return cksmRegisterVfs();
 }
+int sqlite3_unregister_cksumvfs(void){
+  if( sqlite3_vfs_find("cksmvfs") ){
+    sqlite3_vfs_unregister(&cksm_vfs);
+    sqlite3_cancel_auto_extension((void(*)(void))cksmRegisterFunc);
+  }
+  return SQLITE_OK;
+}
 #endif /* defined(SQLITE_CKSUMVFS_STATIC */

 #if !defined(SQLITE_CKSUMVFS_STATIC)
@@ -226,7 +226,7 @@ static int completionNext(sqlite3_vtab_cursor *cur){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            zSql = sqlite3_mprintf(
               "%z%s"
-               "SELECT name FROM \"%w\".sqlite_master",
+               "SELECT name FROM \"%w\".sqlite_schema",
               zSql, zSep, zDb
            );
            if( zSql==0 ) return SQLITE_NOMEM;
@@ -250,7 +250,7 @@ static int completionNext(sqlite3_vtab_cursor *cur){
            const char *zDb = (const char*)sqlite3_column_text(pS2, 1);
            zSql = sqlite3_mprintf(
               "%z%s"
-               "SELECT pti.name FROM \"%w\".sqlite_master AS sm"
+               "SELECT pti.name FROM \"%w\".sqlite_schema AS sm"
                       " JOIN pragma_table_info(sm.name,%Q) AS pti"
               " WHERE sm.type='table'",
               zSql, zSep, zDb, zDb
@@ -776,7 +776,7 @@ static int csvtabColumn(
  CsvCursor *pCur = (CsvCursor*)cur;
  CsvTable *pTab = (CsvTable*)cur->pVtab;
  if( i>=0 && i<pTab->nCol && pCur->azVal[i]!=0 ){
-    sqlite3_result_text(ctx, pCur->azVal[i], -1, SQLITE_STATIC);
+    sqlite3_result_text(ctx, pCur->azVal[i], -1, SQLITE_TRANSIENT);
  }
  return SQLITE_OK;
 }
@@ -395,7 +395,7 @@ static int dump_callback(void *pArg, int nArg, char **azArg, char **azCol){
  if( strcmp(zTable, "sqlite_sequence")==0 ){
    p->xCallback("DELETE FROM sqlite_sequence;\n", p->pArg);
  }else if( sqlite3_strglob("sqlite_stat?", zTable)==0 ){
-    p->xCallback("ANALYZE sqlite_master;\n", p->pArg);
+    p->xCallback("ANALYZE sqlite_schema;\n", p->pArg);
  }else if( strncmp(zTable, "sqlite_", 7)==0 ){
    return 0;
  }else if( strncmp(zSql, "CREATE VIRTUAL TABLE", 20)==0 ){
@@ -404,7 +404,7 @@ static int dump_callback(void *pArg, int nArg, char **azArg, char **azCol){
      p->writableSchema = 1;
    }
    output_formatted(p,
-       "INSERT INTO sqlite_master(type,name,tbl_name,rootpage,sql)"
+       "INSERT INTO sqlite_schema(type,name,tbl_name,rootpage,sql)"
       "VALUES('table','%q','%q',0,'%q');",
       zTable, zTable, zSql);
    return 0;
@@ -646,27 +646,27 @@ int sqlite3_db_dump(
  xCallback("PRAGMA foreign_keys=OFF;\nBEGIN TRANSACTION;\n", pArg);
  if( zTable==0 ){
    run_schema_dump_query(&x,
-      "SELECT name, type, sql FROM \"%w\".sqlite_master "
+      "SELECT name, type, sql FROM \"%w\".sqlite_schema "
      "WHERE sql NOT NULL AND type=='table' AND name!='sqlite_sequence'",
      zSchema
    );
    run_schema_dump_query(&x,
-      "SELECT name, type, sql FROM \"%w\".sqlite_master "
+      "SELECT name, type, sql FROM \"%w\".sqlite_schema "
      "WHERE name=='sqlite_sequence'", zSchema
    );
    output_sql_from_query(&x,
-      "SELECT sql FROM sqlite_master "
+      "SELECT sql FROM sqlite_schema "
      "WHERE sql NOT NULL AND type IN ('index','trigger','view')", 0
    );
  }else{
    run_schema_dump_query(&x,
-      "SELECT name, type, sql FROM \"%w\".sqlite_master "
+      "SELECT name, type, sql FROM \"%w\".sqlite_schema "
      "WHERE tbl_name=%Q COLLATE nocase AND type=='table'"
      "  AND sql NOT NULL",
      zSchema, zTable
    );
    output_sql_from_query(&x,
-      "SELECT sql FROM \"%w\".sqlite_master "
+      "SELECT sql FROM \"%w\".sqlite_schema "
      "WHERE sql NOT NULL"
      "  AND type IN ('index','trigger','view')"
      "  AND tbl_name=%Q COLLATE nocase",
@@ -0,0 +1,634 @@
+/*
+** 2020-06-22
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** Routines to implement arbitrary-precision decimal math.
+**
+** The focus here is on simplicity and correctness, not performance.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdlib.h>
+
+/* Mark a function parameter as unused, to suppress nuisance compiler
+** warnings. */
+#ifndef UNUSED_PARAMETER
+# define UNUSED_PARAMETER(X)  (void)(X)
+#endif
+
+
+/* A decimal object */
+typedef struct Decimal Decimal;
+struct Decimal {
+  char sign;        /* 0 for positive, 1 for negative */
+  char oom;         /* True if an OOM is encountered */
+  char isNull;      /* True if holds a NULL rather than a number */
+  char isInit;      /* True upon initialization */
+  int nDigit;       /* Total number of digits */
+  int nFrac;        /* Number of digits to the right of the decimal point */
+  signed char *a;   /* Array of digits.  Most significant first. */
+};
+
+/*
+** Release memory held by a Decimal, but do not free the object itself.
+*/
+static void decimal_clear(Decimal *p){
+  sqlite3_free(p->a);
+}
+
+/*
+** Destroy a Decimal object
+*/
+static void decimal_free(Decimal *p){
+  if( p ){
+    decimal_clear(p);
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Allocate a new Decimal object.  Initialize it to the number given
+** by the input string.
+*/
+static Decimal *decimal_new(
+  sqlite3_context *pCtx,
+  sqlite3_value *pIn,
+  int nAlt,
+  const unsigned char *zAlt
+){
+  Decimal *p;
+  int n, i;
+  const unsigned char *zIn;
+  int iExp = 0;
+  p = sqlite3_malloc( sizeof(*p) );
+  if( p==0 ) goto new_no_mem;
+  p->sign = 0;
+  p->oom = 0;
+  p->isInit = 1;
+  p->isNull = 0;
+  p->nDigit = 0;
+  p->nFrac = 0;
+  if( zAlt ){
+    n = nAlt,
+    zIn = zAlt;
+  }else{
+    if( sqlite3_value_type(pIn)==SQLITE_NULL ){
+      p->a = 0;
+      p->isNull = 1;
+      return p;
+    }
+    n = sqlite3_value_bytes(pIn);
+    zIn = sqlite3_value_text(pIn);
+  }
+  p->a = sqlite3_malloc64( n+1 );
+  if( p->a==0 ) goto new_no_mem;
+  for(i=0; isspace(zIn[i]); i++){}
+  if( zIn[i]=='-' ){
+    p->sign = 1;
+    i++;
+  }else if( zIn[i]=='+' ){
+    i++;
+  }
+  while( i<n && zIn[i]=='0' ) i++;
+  while( i<n ){
+    char c = zIn[i];
+    if( c>='0' && c<='9' ){
+      p->a[p->nDigit++] = c - '0';
+    }else if( c=='.' ){
+      p->nFrac = p->nDigit + 1;
+    }else if( c=='e' || c=='E' ){
+      int j = i+1;
+      int neg = 0;
+      if( j>=n ) break;
+      if( zIn[j]=='-' ){
+        neg = 1;
+        j++;
+      }else if( zIn[j]=='+' ){
+        j++;
+      }
+      while( j<n && iExp<1000000 ){
+        if( zIn[j]>='0' && zIn[j]<='9' ){
+          iExp = iExp*10 + zIn[j] - '0';
+        }
+        j++;
+      }
+      if( neg ) iExp = -iExp;
+      break;
+    }
+    i++;
+  }
+  if( p->nFrac ){
+    p->nFrac = p->nDigit - (p->nFrac - 1);
+  }
+  if( iExp>0 ){
+    if( p->nFrac>0 ){
+      if( iExp<=p->nFrac ){
+        p->nFrac -= iExp;
+        iExp = 0;
+      }else{
+        iExp -= p->nFrac;
+        p->nFrac = 0;
+      }
+    }
+    if( iExp>0 ){   
+      p->a = sqlite3_realloc64(p->a, p->nDigit + iExp + 1 );
+      if( p->a==0 ) goto new_no_mem;
+      memset(p->a+p->nDigit, 0, iExp);
+      p->nDigit += iExp;
+    }
+  }else if( iExp<0 ){
+    int nExtra;
+    iExp = -iExp;
+    nExtra = p->nDigit - p->nFrac - 1;
+    if( nExtra ){
+      if( nExtra>=iExp ){
+        p->nFrac += iExp;
+        iExp  = 0;
+      }else{
+        iExp -= nExtra;
+        p->nFrac = p->nDigit - 1;
+      }
+    }
+    if( iExp>0 ){
+      p->a = sqlite3_realloc64(p->a, p->nDigit + iExp + 1 );
+      if( p->a==0 ) goto new_no_mem;
+      memmove(p->a+iExp, p->a, p->nDigit);
+      memset(p->a, 0, iExp);
+      p->nDigit += iExp;
+      p->nFrac += iExp;
+    }
+  }
+  return p;
+
+new_no_mem:
+  if( pCtx ) sqlite3_result_error_nomem(pCtx);
+  sqlite3_free(p);
+  return 0;
+}
+
+/*
+** Make the given Decimal the result.
+*/
+static void decimal_result(sqlite3_context *pCtx, Decimal *p){
+  char *z;
+  int i, j;
+  int n;
+  if( p==0 || p->oom ){
+    sqlite3_result_error_nomem(pCtx);
+    return;
+  }
+  if( p->isNull ){
+    sqlite3_result_null(pCtx);
+    return;
+  }
+  z = sqlite3_malloc( p->nDigit+4 );
+  if( z==0 ){
+    sqlite3_result_error_nomem(pCtx);
+    return;
+  }
+  i = 0;
+  if( p->nDigit==0 || (p->nDigit==1 && p->a[0]==0) ){
+    p->sign = 0;
+  }
+  if( p->sign ){
+    z[0] = '-';
+    i = 1;
+  }
+  n = p->nDigit - p->nFrac;
+  if( n<=0 ){
+    z[i++] = '0';
+  }
+  j = 0;
+  while( n>1 && p->a[j]==0 ){
+    j++;
+    n--;
+  }
+  while( n>0  ){
+    z[i++] = p->a[j] + '0';
+    j++;
+    n--;
+  }
+  if( p->nFrac ){
+    z[i++] = '.';
+    do{
+      z[i++] = p->a[j] + '0';
+      j++;
+    }while( j<p->nDigit );
+  }
+  z[i] = 0;
+  sqlite3_result_text(pCtx, z, i, sqlite3_free);
+}
+
+/*
+** SQL Function:   decimal(X)
+**
+** Convert input X into decimal and then back into text
+*/
+static void decimalFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *p = decimal_new(context, argv[0], 0, 0);
+  UNUSED_PARAMETER(argc);
+  decimal_result(context, p);
+  decimal_free(p);
+}
+
+/*
+** Compare to Decimal objects.  Return negative, 0, or positive if the
+** first object is less than, equal to, or greater than the second.
+**
+** Preconditions for this routine:
+**
+**    pA!=0
+**    pA->isNull==0
+**    pB!=0
+**    pB->isNull==0
+*/
+static int decimal_cmp(const Decimal *pA, const Decimal *pB){
+  int nASig, nBSig, rc, n;
+  if( pA->sign!=pB->sign ){
+    return pA->sign ? -1 : +1;
+  }
+  if( pA->sign ){
+    const Decimal *pTemp = pA;
+    pA = pB;
+    pB = pTemp;
+  }
+  nASig = pA->nDigit - pA->nFrac;
+  nBSig = pB->nDigit - pB->nFrac;
+  if( nASig!=nBSig ){
+    return nASig - nBSig;
+  }
+  n = pA->nDigit;
+  if( n>pB->nDigit ) n = pB->nDigit;
+  rc = memcmp(pA->a, pB->a, n);
+  if( rc==0 ){
+    rc = pA->nDigit - pB->nDigit;
+  }
+  return rc;
+}
+
+/*
+** SQL Function:   decimal_cmp(X, Y)
+**
+** Return negative, zero, or positive if X is less then, equal to, or
+** greater than Y.
+*/
+static void decimalCmpFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *pA = 0, *pB = 0;
+  int rc;
+
+  UNUSED_PARAMETER(argc);
+  pA = decimal_new(context, argv[0], 0, 0);
+  if( pA==0 || pA->isNull ) goto cmp_done;
+  pB = decimal_new(context, argv[1], 0, 0);
+  if( pB==0 || pB->isNull ) goto cmp_done;
+  rc = decimal_cmp(pA, pB);
+  if( rc<0 ) rc = -1;
+  else if( rc>0 ) rc = +1;
+  sqlite3_result_int(context, rc);
+cmp_done:
+  decimal_free(pA);
+  decimal_free(pB);
+}
+
+/*
+** Expand the Decimal so that it has a least nDigit digits and nFrac
+** digits to the right of the decimal point.
+*/
+static void decimal_expand(Decimal *p, int nDigit, int nFrac){
+  int nAddSig;
+  int nAddFrac;
+  if( p==0 ) return;
+  nAddFrac = nFrac - p->nFrac;
+  nAddSig = (nDigit - p->nDigit) - nAddFrac;
+  if( nAddFrac==0 && nAddSig==0 ) return;
+  p->a = sqlite3_realloc64(p->a, nDigit+1);
+  if( p->a==0 ){
+    p->oom = 1;
+    return;
+  }
+  if( nAddSig ){
+    memmove(p->a+nAddSig, p->a, p->nDigit);
+    memset(p->a, 0, nAddSig);
+    p->nDigit += nAddSig;
+  }
+  if( nAddFrac ){
+    memset(p->a+p->nDigit, 0, nAddFrac);
+    p->nDigit += nAddFrac;
+    p->nFrac += nAddFrac;
+  }
+}
+
+/*
+** Add the value pB into pA.
+**
+** Both pA and pB might become denormalized by this routine.
+*/
+static void decimal_add(Decimal *pA, Decimal *pB){
+  int nSig, nFrac, nDigit;
+  int i, rc;
+  if( pA==0 ){
+    return;
+  }
+  if( pA->oom || pB==0 || pB->oom ){
+    pA->oom = 1;
+    return;
+  }
+  if( pA->isNull || pB->isNull ){
+    pA->isNull = 1;
+    return;
+  }
+  nSig = pA->nDigit - pA->nFrac;
+  if( nSig && pA->a[0]==0 ) nSig--;
+  if( nSig<pB->nDigit-pB->nFrac ){
+    nSig = pB->nDigit - pB->nFrac;
+  }
+  nFrac = pA->nFrac;
+  if( nFrac<pB->nFrac ) nFrac = pB->nFrac;
+  nDigit = nSig + nFrac + 1;
+  decimal_expand(pA, nDigit, nFrac);
+  decimal_expand(pB, nDigit, nFrac);
+  if( pA->oom || pB->oom ){
+    pA->oom = 1;
+  }else{
+    if( pA->sign==pB->sign ){
+      int carry = 0;
+      for(i=nDigit-1; i>=0; i--){
+        int x = pA->a[i] + pB->a[i] + carry;
+        if( x>=10 ){
+          carry = 1;
+          pA->a[i] = x - 10;
+        }else{
+          carry = 0;
+          pA->a[i] = x;
+        }
+      }
+    }else{
+      signed char *aA, *aB;
+      int borrow = 0;
+      rc = memcmp(pA->a, pB->a, nDigit);
+      if( rc<0 ){
+        aA = pB->a;
+        aB = pA->a;
+        pA->sign = !pA->sign;
+      }else{
+        aA = pA->a;
+        aB = pB->a;
+      }
+      for(i=nDigit-1; i>=0; i--){
+        int x = aA[i] - aB[i] - borrow;
+        if( x<0 ){
+          pA->a[i] = x+10;
+          borrow = 1;
+        }else{
+          pA->a[i] = x;
+          borrow = 0;
+        }
+      }
+    }
+  }
+}
+
+/*
+** Compare text in decimal order.
+*/
+static int decimalCollFunc(
+  void *notUsed,
+  int nKey1, const void *pKey1,
+  int nKey2, const void *pKey2
+){
+  const unsigned char *zA = (const unsigned char*)pKey1;
+  const unsigned char *zB = (const unsigned char*)pKey2;
+  Decimal *pA = decimal_new(0, 0, nKey1, zA);
+  Decimal *pB = decimal_new(0, 0, nKey2, zB);
+  int rc;
+  UNUSED_PARAMETER(notUsed);
+  if( pA==0 || pB==0 ){
+    rc = 0;
+  }else{
+    rc = decimal_cmp(pA, pB);
+  }
+  decimal_free(pA);
+  decimal_free(pB);
+  return rc;
+}
+
+
+/*
+** SQL Function:   decimal_add(X, Y)
+**                 decimal_sub(X, Y)
+**
+** Return the sum or difference of X and Y.
+*/
+static void decimalAddFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *pA = decimal_new(context, argv[0], 0, 0);
+  Decimal *pB = decimal_new(context, argv[1], 0, 0);
+  UNUSED_PARAMETER(argc);
+  decimal_add(pA, pB);
+  decimal_result(context, pA);
+  decimal_free(pA);
+  decimal_free(pB);
+}
+static void decimalSubFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *pA = decimal_new(context, argv[0], 0, 0);
+  Decimal *pB = decimal_new(context, argv[1], 0, 0);
+  UNUSED_PARAMETER(argc);
+  if( pB==0 ) return;
+  pB->sign = !pB->sign;
+  decimal_add(pA, pB);
+  decimal_result(context, pA);
+  decimal_free(pA);
+  decimal_free(pB);
+}
+
+/* Aggregate funcion:   decimal_sum(X)
+**
+** Works like sum() except that it uses decimal arithmetic for unlimited
+** precision.
+*/
+static void decimalSumStep(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *p;
+  Decimal *pArg;
+  UNUSED_PARAMETER(argc);
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( p==0 ) return;
+  if( !p->isInit ){
+    p->isInit = 1;
+    p->a = sqlite3_malloc(2);
+    if( p->a==0 ){
+      p->oom = 1;
+    }else{
+      p->a[0] = 0;
+    }
+    p->nDigit = 1;
+    p->nFrac = 0;
+  }
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  pArg = decimal_new(context, argv[0], 0, 0);
+  decimal_add(p, pArg);
+  decimal_free(pArg);
+}
+static void decimalSumInverse(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *p;
+  Decimal *pArg;
+  UNUSED_PARAMETER(argc);
+  p = sqlite3_aggregate_context(context, sizeof(*p));
+  if( p==0 ) return;
+  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+  pArg = decimal_new(context, argv[0], 0, 0);
+  if( pArg ) pArg->sign = !pArg->sign;
+  decimal_add(p, pArg);
+  decimal_free(pArg);
+}
+static void decimalSumValue(sqlite3_context *context){
+  Decimal *p = sqlite3_aggregate_context(context, 0);
+  if( p==0 ) return;
+  decimal_result(context, p);
+}
+static void decimalSumFinalize(sqlite3_context *context){
+  Decimal *p = sqlite3_aggregate_context(context, 0);
+  if( p==0 ) return;
+  decimal_result(context, p);
+  decimal_clear(p);
+}
+
+/*
+** SQL Function:   decimal_mul(X, Y)
+**
+** Return the product of X and Y.
+**
+** All significant digits after the decimal point are retained.
+** Trailing zeros after the decimal point are omitted as long as
+** the number of digits after the decimal point is no less than
+** either the number of digits in either input.
+*/
+static void decimalMulFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  Decimal *pA = decimal_new(context, argv[0], 0, 0);
+  Decimal *pB = decimal_new(context, argv[1], 0, 0);
+  signed char *acc = 0;
+  int i, j, k;
+  int minFrac;
+  UNUSED_PARAMETER(argc);
+  if( pA==0 || pA->oom || pA->isNull
+   || pB==0 || pB->oom || pB->isNull 
+  ){
+    goto mul_end;
+  }
+  acc = sqlite3_malloc64( pA->nDigit + pB->nDigit + 2 );
+  if( acc==0 ){
+    sqlite3_result_error_nomem(context);
+    goto mul_end;
+  }
+  memset(acc, 0, pA->nDigit + pB->nDigit + 2);
+  minFrac = pA->nFrac;
+  if( pB->nFrac<minFrac ) minFrac = pB->nFrac;
+  for(i=pA->nDigit-1; i>=0; i--){
+    signed char f = pA->a[i];
+    int carry = 0, x;
+    for(j=pB->nDigit-1, k=i+j+3; j>=0; j--, k--){
+      x = acc[k] + f*pB->a[j] + carry;
+      acc[k] = x%10;
+      carry = x/10;
+    }
+    x = acc[k] + carry;
+    acc[k] = x%10;
+    acc[k-1] += x/10;
+  }
+  sqlite3_free(pA->a);
+  pA->a = acc;
+  acc = 0;
+  pA->nDigit += pB->nDigit + 2;
+  pA->nFrac += pB->nFrac;
+  pA->sign ^= pB->sign;
+  while( pA->nFrac>minFrac && pA->a[pA->nDigit-1]==0 ){
+    pA->nFrac--;
+    pA->nDigit--;
+  }
+  decimal_result(context, pA);
+
+mul_end:
+  sqlite3_free(acc);
+  decimal_free(pA);
+  decimal_free(pB);
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_decimal_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  static const struct {
+    const char *zFuncName;
+    int nArg;
+    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  } aFunc[] = {
+    { "decimal",       1,   decimalFunc        },
+    { "decimal_cmp",   2,   decimalCmpFunc     },
+    { "decimal_add",   2,   decimalAddFunc     },
+    { "decimal_sub",   2,   decimalSubFunc     },
+    { "decimal_mul",   2,   decimalMulFunc     },
+  };
+  unsigned int i;
+  (void)pzErrMsg;  /* Unused parameter */
+
+  SQLITE_EXTENSION_INIT2(pApi);
+
+  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
+    rc = sqlite3_create_function(db, aFunc[i].zFuncName, aFunc[i].nArg,
+                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC,
+                   0, aFunc[i].xFunc, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_window_function(db, "decimal_sum", 1,
+                   SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC, 0,
+                   decimalSumStep, decimalSumFinalize,
+                   decimalSumValue, decimalSumInverse, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_collation(db, "decimal", SQLITE_UTF8,
+                                  0, decimalCollFunc);
+  }
+  return rc;
+}
@@ -16,7 +16,7 @@
 ** Usage example:
 **
 **     .load ./explain
-**     SELECT p2 FROM explain('SELECT * FROM sqlite_master')
+**     SELECT p2 FROM explain('SELECT * FROM sqlite_schema')
 **      WHERE opcode='OpenRead';
 **
 ** This module was originally written to help simplify SQLite testing,
@@ -26,16 +26,76 @@
 **
 ** Examples:
 **
-**     ieee754(2.0)       ->     'ieee754(2,0)'
-**     ieee754(45.25)     ->     'ieee754(181,-2)'
-**     ieee754(2, 0)      ->     2.0
-**     ieee754(181, -2)   ->     45.25
+**     ieee754(2.0)             ->     'ieee754(2,0)'
+**     ieee754(45.25)           ->     'ieee754(181,-2)'
+**     ieee754(2, 0)            ->     2.0
+**     ieee754(181, -2)         ->     45.25
+**
+** Two additional functions break apart the one-argument ieee754()
+** result into separate integer values:
+**
+**     ieee754_mantissa(45.25)  ->     181
+**     ieee754_exponent(45.25)  ->     -2
+**
+** These functions convert binary64 numbers into blobs and back again.
+**
+**     ieee754_from_blob(x'3ff0000000000000')  ->  1.0
+**     ieee754_to_blob(1.0)                    ->  x'3ff0000000000000'
+**
+** In all single-argument functions, if the argument is an 8-byte blob
+** then that blob is interpreted as a big-endian binary64 value.
+**
+**
+** EXACT DECIMAL REPRESENTATION OF BINARY64 VALUES
+** -----------------------------------------------
+**
+** This extension in combination with the separate 'decimal' extension
+** can be used to compute the exact decimal representation of binary64
+** values.  To begin, first compute a table of exponent values:
+**
+**    CREATE TABLE pow2(x INTEGER PRIMARY KEY, v TEXT);
+**    WITH RECURSIVE c(x,v) AS (
+**      VALUES(0,'1')
+**      UNION ALL
+**      SELECT x+1, decimal_mul(v,'2') FROM c WHERE x+1<=971
+**    ) INSERT INTO pow2(x,v) SELECT x, v FROM c;
+**    WITH RECURSIVE c(x,v) AS (
+**      VALUES(-1,'0.5')
+**      UNION ALL
+**      SELECT x-1, decimal_mul(v,'0.5') FROM c WHERE x-1>=-1075
+**    ) INSERT INTO pow2(x,v) SELECT x, v FROM c;
+**
+** Then, to compute the exact decimal representation of a floating
+** point value (the value 47.49 is used in the example) do:
+**
+**    WITH c(n) AS (VALUES(47.49))
+**          ---------------^^^^^---- Replace with whatever you want
+**    SELECT decimal_mul(ieee754_mantissa(c.n),pow2.v)
+**      FROM pow2, c WHERE pow2.x=ieee754_exponent(c.n);
+**
+** Here is a query to show various boundry values for the binary64
+** number format:
+**
+**    WITH c(name,bin) AS (VALUES
+**       ('minimum positive value',        x'0000000000000001'),
+**       ('maximum subnormal value',       x'000fffffffffffff'),
+**       ('mininum positive nornal value', x'0010000000000000'),
+**       ('maximum value',                 x'7fefffffffffffff'))
+**    SELECT c.name, decimal_mul(ieee754_mantissa(c.bin),pow2.v)
+**      FROM pow2, c WHERE pow2.x=ieee754_exponent(c.bin);
+**
 */
 #include "sqlite3ext.h"
 SQLITE_EXTENSION_INIT1
 #include <assert.h>
 #include <string.h>

+/* Mark a function parameter as unused, to suppress nuisance compiler
+** warnings. */
+#ifndef UNUSED_PARAMETER
+# define UNUSED_PARAMETER(X)  (void)(X)
+#endif
+
 /*
 ** Implementation of the ieee754() function
 */
@@ -51,8 +111,19 @@ static void ieee754func(
    int isNeg;
    char zResult[100];
    assert( sizeof(m)==sizeof(r) );
-    if( sqlite3_value_type(argv[0])!=SQLITE_FLOAT ) return;
-    r = sqlite3_value_double(argv[0]);
+    if( sqlite3_value_type(argv[0])==SQLITE_BLOB
+     && sqlite3_value_bytes(argv[0])==sizeof(r)
+    ){
+      const unsigned char *x = sqlite3_value_blob(argv[0]);
+      unsigned int i;
+      sqlite3_uint64 v = 0;
+      for(i=0; i<sizeof(r); i++){
+        v = (v<<8) | x[i];
+      }
+      memcpy(&r, &v, sizeof(r));
+    }else{
+      r = sqlite3_value_double(argv[0]);
+    }
    if( r<0.0 ){
      isNeg = 1;
      r = -r;
@@ -66,27 +137,49 @@ static void ieee754func(
    }else{
      e = a>>52;
      m = a & ((((sqlite3_int64)1)<<52)-1);
-      m |= ((sqlite3_int64)1)<<52;
+      if( e==0 ){
+        m <<= 1;
+      }else{
+        m |= ((sqlite3_int64)1)<<52;
+      }
      while( e<1075 && m>0 && (m&1)==0 ){
        m >>= 1;
        e++;
      }
      if( isNeg ) m = -m;
    }
-    sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
-                     m, e-1075);
-    sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
-  }else if( argc==2 ){
+    switch( *(int*)sqlite3_user_data(context) ){
+      case 0:
+        sqlite3_snprintf(sizeof(zResult), zResult, "ieee754(%lld,%d)",
+                         m, e-1075);
+        sqlite3_result_text(context, zResult, -1, SQLITE_TRANSIENT);
+        break;
+      case 1:
+        sqlite3_result_int64(context, m);
+        break;
+      case 2:
+        sqlite3_result_int(context, e-1075);
+        break;
+    }
+  }else{
    sqlite3_int64 m, e, a;
    double r;
    int isNeg = 0;
    m = sqlite3_value_int64(argv[0]);
    e = sqlite3_value_int64(argv[1]);
+
+    /* Limit the range of e.  Ticket 22dea1cfdb9151e4 2021-03-02 */
+    if( e>10000 ){
+      e = 10000;
+    }else if( e<-10000 ){
+      e = -10000;
+    }
+
    if( m<0 ){
      isNeg = 1;
      m = -m;
      if( m<0 ) return;
-    }else if( m==0 && e>1000 && e<1000 ){
+    }else if( m==0 && e>-1000 && e<1000 ){
      sqlite3_result_double(context, 0.0);
      return;
    }
@@ -99,8 +192,13 @@ static void ieee754func(
      e--;
    }
    e += 1075;
-    if( e<0 ) e = m = 0;
-    if( e>0x7ff ) e = 0x7ff;
+    if( e<=0 ){
+      /* Subnormal */
+      m >>= 1-e;
+      e = 0;
+    }else if( e>0x7ff ){
+      e = 0x7ff;
+    }
    a = m & ((((sqlite3_int64)1)<<52)-1);
    a |= e<<52;
    if( isNeg ) a |= ((sqlite3_uint64)1)<<63;
@@ -109,6 +207,51 @@ static void ieee754func(
  }
 }

+/*
+** Functions to convert between blobs and floats.
+*/
+static void ieee754func_from_blob(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  UNUSED_PARAMETER(argc);
+  if( sqlite3_value_type(argv[0])==SQLITE_BLOB
+   && sqlite3_value_bytes(argv[0])==sizeof(double)
+  ){
+    double r;
+    const unsigned char *x = sqlite3_value_blob(argv[0]);
+    unsigned int i;
+    sqlite3_uint64 v = 0;
+    for(i=0; i<sizeof(r); i++){
+      v = (v<<8) | x[i];
+    }
+    memcpy(&r, &v, sizeof(r));
+    sqlite3_result_double(context, r);
+  }
+}
+static void ieee754func_to_blob(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  UNUSED_PARAMETER(argc);
+  if( sqlite3_value_type(argv[0])==SQLITE_FLOAT
+   || sqlite3_value_type(argv[0])==SQLITE_INTEGER
+  ){
+    double r = sqlite3_value_double(argv[0]);
+    sqlite3_uint64 v;
+    unsigned char a[sizeof(r)];
+    unsigned int i;
+    memcpy(&v, &r, sizeof(r));
+    for(i=1; i<=sizeof(r); i++){
+      a[sizeof(r)-i] = v&0xff;
+      v >>= 8;
+    }
+    sqlite3_result_blob(context, a, sizeof(r), SQLITE_TRANSIENT);
+  }
+}
+

 #ifdef _WIN32
 __declspec(dllexport)
@@ -118,16 +261,29 @@ int sqlite3_ieee_init(
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
 ){
+  static const struct {
+    char *zFName;
+    int nArg;
+    int iAux;
+    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
+  } aFunc[] = {
+    { "ieee754",           1,   0, ieee754func },
+    { "ieee754",           2,   0, ieee754func },
+    { "ieee754_mantissa",  1,   1, ieee754func },
+    { "ieee754_exponent",  1,   2, ieee754func },
+    { "ieee754_to_blob",   1,   0, ieee754func_to_blob },
+    { "ieee754_from_blob", 1,   0, ieee754func_from_blob },
+
+  };
+  unsigned int i;
  int rc = SQLITE_OK;
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
-  rc = sqlite3_create_function(db, "ieee754", 1, 
-                               SQLITE_UTF8|SQLITE_INNOCUOUS, 0,
-                               ieee754func, 0, 0);
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_create_function(db, "ieee754", 2,
-                                 SQLITE_UTF8|SQLITE_INNOCUOUS, 0,
-                                 ieee754func, 0, 0);
+  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
+    rc = sqlite3_create_function(db, aFunc[i].zFName, aFunc[i].nArg,	
+                               SQLITE_UTF8|SQLITE_INNOCUOUS,
+                               (void*)&aFunc[i].iAux,
+                               aFunc[i].xFunc, 0, 0);
  }
  return rc;
 }
@@ -42,6 +42,10 @@ SQLITE_EXTENSION_INIT1
 # define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
 #endif

+#ifndef deliberate_fall_through
+# define deliberate_fall_through
+#endif
+
 /*
 ** Versions of isspace(), isalnum() and isdigit() to which it is safe
 ** to pass signed char values.
@@ -254,6 +258,7 @@ static int jsonGrow(JsonString *p, u32 N){
 /* Append N bytes from zIn onto the end of the JsonString string.
 */
 static void jsonAppendRaw(JsonString *p, const char *zIn, u32 N){
+  if( N==0 ) return;
  if( (N+p->nUsed >= p->nAlloc) && jsonGrow(p,N)!=0 ) return;
  memcpy(p->zBuf+p->nUsed, zIn, N);
  p->nUsed += N;
@@ -459,7 +464,7 @@ static void jsonRenderNode(
        jsonAppendString(pOut, pNode->u.zJContent, pNode->n);
        break;
      }
-      /* Fall through into the next case */
+      /* no break */ deliberate_fall_through
    }
    case JSON_REAL:
    case JSON_INT: {
@@ -600,7 +605,7 @@ static void jsonReturn(
      sqlite3_result_int64(pCtx, i);
      int_done:
      break;
-      int_as_real: /* fall through to real */;
+      int_as_real: i=0; /* no break */ deliberate_fall_through
    }
    case JSON_REAL: {
      double r;
@@ -2303,6 +2308,7 @@ static int jsonEachColumn(
      }
      /* For json_each() path and root are the same so fall through
      ** into the root case */
+      /* no break */ deliberate_fall_through
    }
    default: {
      const char *zRoot = p->zRoot;
@@ -43,7 +43,7 @@ int sqlite3_mmap_warm(sqlite3 *db, const char *zDb){
  if( 0==sqlite3_get_autocommit(db) ) return SQLITE_MISUSE;

  /* Open a read-only transaction on the file in question */
-  zSql = sqlite3_mprintf("BEGIN; SELECT * FROM %s%q%ssqlite_master", 
+  zSql = sqlite3_mprintf("BEGIN; SELECT * FROM %s%q%ssqlite_schema", 
      (zDb ? "'" : ""), (zDb ? zDb : ""), (zDb ? "'." : "")
  );
  if( zSql==0 ) return SQLITE_NOMEM;
@@ -286,6 +286,13 @@ static const unsigned char sqlite3CtypeMap[256] = {
 #define TK_VARIABLE TK_LITERAL
 #define TK_BLOB     TK_LITERAL

+/* Disable nuisence warnings about case fall-through */
+#if !defined(deliberate_fall_through) && defined(__GCC__) && __GCC__>=7
+# define deliberate_fall_through __attribute__((fallthrough));
+#else
+# define deliberate_fall_through
+#endif
+
 /*
 ** Return the length (in bytes) of the token that begins at z[0]. 
 ** Store the token type in *tokenType before returning.
@@ -436,6 +443,7 @@ static int sqlite3GetToken(const unsigned char *z, int *tokenType){
      }
      /* If the next character is a digit, this is a floating point
      ** number that begins with ".".  Fall thru into the next case */
+      /* no break */ deliberate_fall_through
    }
    case CC_DIGIT: {
      *tokenType = TK_INTEGER;
@@ -528,6 +536,7 @@ static int sqlite3GetToken(const unsigned char *z, int *tokenType){
      }
      /* If it is not a BLOB literal, then it must be an ID, since no
      ** SQL keywords start with the letter 'x'.  Fall through */
+      /* no break */ deliberate_fall_through
    }
    case CC_ID: {
      i = 1;
@@ -166,7 +166,7 @@ static void scrubBackupOpenSrc(ScrubState *p){
                      sqlite3_errmsg(p->dbSrc));
    return;
  }
-  p->rcErr = sqlite3_exec(p->dbSrc, "SELECT 1 FROM sqlite_master; BEGIN;",
+  p->rcErr = sqlite3_exec(p->dbSrc, "SELECT 1 FROM sqlite_schema; BEGIN;",
                          0, 0, 0);
  if( p->rcErr ){
    scrubBackupErr(p,
@@ -535,7 +535,7 @@ int sqlite3_scrub_backup(
  /* Copy all of the btrees */
  scrubBackupBtree(&s, 1, 0);
  pStmt = scrubBackupPrepare(&s, s.dbSrc,
-       "SELECT rootpage FROM sqlite_master WHERE coalesce(rootpage,0)>0");
+       "SELECT rootpage FROM sqlite_schema WHERE coalesce(rootpage,0)>0");
  if( pStmt==0 ) goto scrub_abort;
  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    i = (u32)sqlite3_column_int(pStmt, 0);
@@ -106,10 +106,10 @@ struct series_cursor {
 */
 static int seriesConnect(
  sqlite3 *db,
-  void *pAux,
-  int argc, const char *const*argv,
+  void *pUnused,
+  int argcUnused, const char *const*argvUnused,
  sqlite3_vtab **ppVtab,
-  char **pzErr
+  char **pzErrUnused
 ){
  sqlite3_vtab *pNew;
  int rc;
@@ -120,6 +120,10 @@ static int seriesConnect(
 #define SERIES_COLUMN_STOP  2
 #define SERIES_COLUMN_STEP  3

+  (void)pUnused;
+  (void)argcUnused;
+  (void)argvUnused;
+  (void)pzErrUnused;
  rc = sqlite3_declare_vtab(db,
     "CREATE TABLE x(value,start hidden,stop hidden,step hidden)");
  if( rc==SQLITE_OK ){
@@ -142,8 +146,9 @@ static int seriesDisconnect(sqlite3_vtab *pVtab){
 /*
 ** Constructor for a new series_cursor object.
 */
-static int seriesOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
+static int seriesOpen(sqlite3_vtab *pUnused, sqlite3_vtab_cursor **ppCursor){
  series_cursor *pCur;
+  (void)pUnused;
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
@@ -242,7 +247,8 @@ static int seriesEof(sqlite3_vtab_cursor *cur){
 **    4:    step=VALUE
 **
 ** Also, if bit 8 is set, that means that the series should be output
-** in descending order rather than in ascending order.
+** in descending order rather than in ascending order.  If bit 16 is
+** set, then output must appear in ascending order.
 **
 ** This routine should initialize the cursor and position it so that it
 ** is pointing at the first row, or pointing off the end of the table
@@ -250,11 +256,12 @@ static int seriesEof(sqlite3_vtab_cursor *cur){
 */
 static int seriesFilter(
  sqlite3_vtab_cursor *pVtabCursor, 
-  int idxNum, const char *idxStr,
+  int idxNum, const char *idxStrUnused,
  int argc, sqlite3_value **argv
 ){
  series_cursor *pCur = (series_cursor *)pVtabCursor;
  int i = 0;
+  (void)idxStrUnused;
  if( idxNum & 1 ){
    pCur->mnValue = sqlite3_value_int64(argv[i++]);
  }else{
@@ -267,7 +274,12 @@ static int seriesFilter(
  }
  if( idxNum & 4 ){
    pCur->iStep = sqlite3_value_int64(argv[i++]);
-    if( pCur->iStep<1 ) pCur->iStep = 1;
+    if( pCur->iStep==0 ){
+      pCur->iStep = 1;
+    }else if( pCur->iStep<0 ){
+      pCur->iStep = -pCur->iStep;
+      if( (idxNum & 16)==0 ) idxNum |= 8;
+    }
  }else{
    pCur->iStep = 1;
  }
@@ -311,7 +323,7 @@ static int seriesFilter(
 **  (8)  output in descending order
 */
 static int seriesBestIndex(
-  sqlite3_vtab *tab,
+  sqlite3_vtab *tabUnused,
  sqlite3_index_info *pIdxInfo
 ){
  int i, j;              /* Loop over constraints */
@@ -325,6 +337,7 @@ static int seriesBestIndex(
  ** are the last three columns in the virtual table. */
  assert( SERIES_COLUMN_STOP == SERIES_COLUMN_START+1 );
  assert( SERIES_COLUMN_STEP == SERIES_COLUMN_START+2 );
+  (void)tabUnused;
  aIdx[0] = aIdx[1] = aIdx[2] = -1;
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
@@ -360,7 +373,11 @@ static int seriesBestIndex(
    pIdxInfo->estimatedCost = (double)(2 - ((idxNum&4)!=0));
    pIdxInfo->estimatedRows = 1000;
    if( pIdxInfo->nOrderBy==1 ){
-      if( pIdxInfo->aOrderBy[0].desc ) idxNum |= 8;
+      if( pIdxInfo->aOrderBy[0].desc ){
+        idxNum |= 8;
+      }else{
+        idxNum |= 16;
+      }
      pIdxInfo->orderByConsumed = 1;
    }
  }else{
@@ -398,6 +415,10 @@ static sqlite3_module seriesModule = {
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
+  0,                         /* xSavepoint */
+  0,                         /* xRelease */
+  0,                         /* xRollbackTo */
+  0                          /* xShadowName */
 };

 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -31,7 +31,10 @@ SQLITE_EXTENSION_INIT1
 #include <assert.h>
 #include <string.h>
 #include <stdarg.h>
+
+#ifndef SQLITE_AMALGAMATION
 typedef sqlite3_uint64 u64;
+#endif /* SQLITE_AMALGAMATION */

 /******************************************************************************
 ** The Hash Engine
@@ -621,9 +624,11 @@ static void sha3QueryFunc(
    }
    nCol = sqlite3_column_count(pStmt);
    z = sqlite3_sql(pStmt);
-    n = (int)strlen(z);
-    hash_step_vformat(&cx,"S%d:",n);
-    SHA3Update(&cx,(unsigned char*)z,n);
+    if( z ){
+      n = (int)strlen(z);
+      hash_step_vformat(&cx,"S%d:",n);
+      SHA3Update(&cx,(unsigned char*)z,n);
+    }

    /* Compute a hash over the result of the query */
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
@@ -17,6 +17,7 @@
 #include "sqlite3ext.h"
 SQLITE_EXTENSION_INIT1
 #include <zlib.h>
+#include <assert.h>

 /*
 ** Implementation of the "sqlar_compress(X)" SQL function.
@@ -811,7 +811,7 @@ int sqlite3_vfsstat_init(
  if( rc==SQLITE_OK ){
    rc = vstatRegister(db, pzErrMsg, pApi);
    if( rc==SQLITE_OK ){
-      rc = sqlite3_auto_extension(vstatRegister);
+      rc = sqlite3_auto_extension((void(*)(void))vstatRegister);
    }
  }
  if( rc==SQLITE_OK ) rc = SQLITE_OK_LOAD_PERMANENTLY;
@@ -220,7 +220,7 @@ static int wholenumberBestIndex(
    pIdxInfo->orderByConsumed = 1;
  }
  if( (idxNum & 12)==0 ){
-    pIdxInfo->estimatedCost = (double)100000000;
+    pIdxInfo->estimatedCost = 1e99;
  }else if( (idxNum & 3)==0 ){
    pIdxInfo->estimatedCost = (double)5;
  }else{
@@ -523,14 +523,16 @@ static int zipfileAppendData(
  const u8 *aWrite,
  int nWrite
 ){
-  size_t n;
-  fseek(pTab->pWriteFd, (long)pTab->szCurrent, SEEK_SET);
-  n = fwrite(aWrite, 1, nWrite, pTab->pWriteFd);
-  if( (int)n!=nWrite ){
-    pTab->base.zErrMsg = sqlite3_mprintf("error in fwrite()");
-    return SQLITE_ERROR;
+  if( nWrite>0 ){
+    size_t n = nWrite;
+    fseek(pTab->pWriteFd, (long)pTab->szCurrent, SEEK_SET);
+    n = fwrite(aWrite, 1, nWrite, pTab->pWriteFd);
+    if( (int)n!=nWrite ){
+      pTab->base.zErrMsg = sqlite3_mprintf("error in fwrite()");
+      return SQLITE_ERROR;
+    }
+    pTab->szCurrent += nWrite;
  }
-  pTab->szCurrent += nWrite;
  return SQLITE_OK;
 }

@@ -183,6 +183,13 @@ int main(int argc, char **argv){
      break;
  }

+  if( nStatStep>0 ){
+    sqlite3_int64 nUsed;
+    sqlite3_int64 nHighwater;
+    sqlite3_status64(SQLITE_STATUS_MEMORY_USED, &nUsed, &nHighwater, 0);
+    fprintf(stdout, "memory used=%lld highwater=%lld\n", nUsed, nHighwater);
+  }
+
  sqlite3_free(zErrmsg);
  return (rc==SQLITE_OK || rc==SQLITE_DONE) ? 0 : 1;
 }
@@ -268,6 +268,14 @@ tablE t1 USING FTs5(c);
      DELETE FROM t1 WHERE rowid = 1;
      INSERT INTO t1 VALUES('a b c');
    }
+    4 {
+      creAte virTUal tablE	t1	USING FTs5(c);
+      INSERT INTO t1 VALUES('a b c');
+      INSERT INTO t1 VALUES('a b c');
+    } {
+      DELETE FROM t1 WHERE rowid = 1;
+      INSERT INTO t1 VALUES('a b c');
+    }

  } {
    forcedelete test.db test.db2
@@ -975,7 +975,7 @@ static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){
  rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pTblIter, &p->zErrmsg, 
    sqlite3_mprintf(
      "SELECT rbu_target_name(name, type='view') AS target, name "
-      "FROM sqlite_master "
+      "FROM sqlite_schema "
      "WHERE type IN ('table', 'view') AND target IS NOT NULL "
      " %s "
      "ORDER BY name"
@@ -984,7 +984,7 @@ static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){
  if( rc==SQLITE_OK ){
    rc = prepareAndCollectError(p->dbMain, &pIter->pIdxIter, &p->zErrmsg,
        "SELECT name, rootpage, sql IS NULL OR substr(8, 6)=='UNIQUE' "
-        "  FROM main.sqlite_master "
+        "  FROM main.sqlite_schema "
        "  WHERE type='index' AND tbl_name = ?"
    );
  }
@@ -1156,12 +1156,12 @@ static void rbuFinalize(sqlite3rbu *p, sqlite3_stmt *pStmt){
 **
 ** ALGORITHM:
 **
-**   if( no entry exists in sqlite_master ){
+**   if( no entry exists in sqlite_schema ){
 **     return RBU_PK_NOTABLE
 **   }else if( sql for the entry starts with "CREATE VIRTUAL" ){
 **     return RBU_PK_VTAB
 **   }else if( "PRAGMA index_list()" for the table contains a "pk" index ){
-**     if( the index that is the pk exists in sqlite_master ){
+**     if( the index that is the pk exists in sqlite_schema ){
 **       *piPK = rootpage of that index.
 **       return RBU_PK_EXTERNAL
 **     }else{
@@ -1181,9 +1181,9 @@ static void rbuTableType(
  int *piPk
 ){
  /*
-  ** 0) SELECT count(*) FROM sqlite_master where name=%Q AND IsVirtual(%Q)
+  ** 0) SELECT count(*) FROM sqlite_schema where name=%Q AND IsVirtual(%Q)
  ** 1) PRAGMA index_list = ?
-  ** 2) SELECT count(*) FROM sqlite_master where name=%Q 
+  ** 2) SELECT count(*) FROM sqlite_schema where name=%Q 
  ** 3) PRAGMA table_info = ?
  */
  sqlite3_stmt *aStmt[4] = {0, 0, 0, 0};
@@ -1195,7 +1195,7 @@ static void rbuTableType(
  p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[0], &p->zErrmsg, 
    sqlite3_mprintf(
          "SELECT (sql LIKE 'create virtual%%'), rootpage"
-          "  FROM sqlite_master"
+          "  FROM sqlite_schema"
          " WHERE name=%Q", zTab
  ));
  if( p->rc!=SQLITE_OK || sqlite3_step(aStmt[0])!=SQLITE_ROW ){
@@ -1218,7 +1218,7 @@ static void rbuTableType(
    if( zOrig && zIdx && zOrig[0]=='p' ){
      p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[2], &p->zErrmsg, 
          sqlite3_mprintf(
-            "SELECT rootpage FROM sqlite_master WHERE name = %Q", zIdx
+            "SELECT rootpage FROM sqlite_schema WHERE name = %Q", zIdx
      ));
      if( p->rc==SQLITE_OK ){
        if( sqlite3_step(aStmt[2])==SQLITE_ROW ){
@@ -2038,7 +2038,7 @@ static void rbuCreateImposterTable2(sqlite3rbu *p, RbuObjIter *pIter){
    ** This is needed for the argument to "PRAGMA index_xinfo". Set
    ** zIdx to point to a nul-terminated string containing this name. */
    p->rc = prepareAndCollectError(p->dbMain, &pQuery, &p->zErrmsg, 
-        "SELECT name FROM sqlite_master WHERE rootpage = ?"
+        "SELECT name FROM sqlite_schema WHERE rootpage = ?"
    );
    if( p->rc==SQLITE_OK ){
      sqlite3_bind_int(pQuery, 1, tnum);
@@ -2211,7 +2211,7 @@ static char *rbuObjIterGetIndexWhere(sqlite3rbu *p, RbuObjIter *pIter){

  if( rc==SQLITE_OK ){
    rc = prepareAndCollectError(p->dbMain, &pStmt, &p->zErrmsg,
-        "SELECT trim(sql) FROM sqlite_master WHERE type='index' AND name=?"
+        "SELECT trim(sql) FROM sqlite_schema WHERE type='index' AND name=?"
    );
  }
  if( rc==SQLITE_OK ){
@@ -2793,7 +2793,7 @@ static void rbuOpenDatabase(sqlite3rbu *p, int *pbRetry){
      int bOk = 0;
      sqlite3_stmt *pCnt = 0;
      p->rc = prepareAndCollectError(p->dbRbu, &pCnt, &p->zErrmsg,
-          "SELECT count(*) FROM stat.sqlite_master"
+          "SELECT count(*) FROM stat.sqlite_schema"
      );
      if( p->rc==SQLITE_OK 
       && sqlite3_step(pCnt)==SQLITE_ROW
@@ -2897,7 +2897,7 @@ static void rbuOpenDatabase(sqlite3rbu *p, int *pbRetry){
  if( p->rc==SQLITE_OK ){
    p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p);
  }
-  rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_master");
+  rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_schema");

  /* Mark the database file just opened as an RBU target database. If 
  ** this call returns SQLITE_NOTFOUND, then the RBU vfs is not in use.
@@ -2990,7 +2990,7 @@ static void rbuSetupCheckpoint(sqlite3rbu *p, RbuState *pState){
  if( pState==0 ){
    p->eStage = 0;
    if( p->rc==SQLITE_OK ){
-      p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_master", 0, 0, 0);
+      p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_schema", 0, 0, 0);
    }
  }

@@ -3581,7 +3581,7 @@ static void rbuCreateTargetSchema(sqlite3rbu *p){
  p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=1", 0,0, &p->zErrmsg);
  if( p->rc==SQLITE_OK ){
    p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 
-      "SELECT sql FROM sqlite_master WHERE sql!='' AND rootpage!=0"
+      "SELECT sql FROM sqlite_schema WHERE sql!='' AND rootpage!=0"
      " AND name!='sqlite_sequence' "
      " ORDER BY type DESC"
    );
@@ -3596,13 +3596,13 @@ static void rbuCreateTargetSchema(sqlite3rbu *p){

  if( p->rc==SQLITE_OK ){
    p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, 
-        "SELECT * FROM sqlite_master WHERE rootpage=0 OR rootpage IS NULL" 
+        "SELECT * FROM sqlite_schema WHERE rootpage=0 OR rootpage IS NULL" 
    );
  }

  if( p->rc==SQLITE_OK ){
    p->rc = prepareAndCollectError(p->dbMain, &pInsert, &p->zErrmsg, 
-        "INSERT INTO sqlite_master VALUES(?,?,?,?,?)"
+        "INSERT INTO sqlite_schema VALUES(?,?,?,?,?)"
    );
  }

@@ -3865,7 +3865,7 @@ static void rbuIndexCntFunc(
  assert( nVal==1 );
  
  rc = prepareFreeAndCollectError(db, &pStmt, &zErrmsg, 
-      sqlite3_mprintf("SELECT count(*) FROM sqlite_master "
+      sqlite3_mprintf("SELECT count(*) FROM sqlite_schema "
        "WHERE type='index' AND tbl_name = %Q", sqlite3_value_text(apVal[0]))
  );
  if( rc!=SQLITE_OK ){
@@ -3916,7 +3916,7 @@ static void rbuInitPhaseOneSteps(sqlite3rbu *p){
    ** occurs, nPhaseOneStep will be left set to -1. */
    if( p->rc==SQLITE_OK ){
      p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg,
-          "SELECT 1 FROM sqlite_master WHERE tbl_name = 'rbu_count'"
+          "SELECT 1 FROM sqlite_schema WHERE tbl_name = 'rbu_count'"
      );
    }
    if( p->rc==SQLITE_OK ){
@@ -4828,22 +4828,24 @@ static int rbuVfsShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
 #endif

  assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) );
-  if( pRbu && (pRbu->eStage==RBU_STAGE_OAL || pRbu->eStage==RBU_STAGE_MOVE) ){
-    /* Magic number 1 is the WAL_CKPT_LOCK lock. Preventing SQLite from
-    ** taking this lock also prevents any checkpoints from occurring. 
-    ** todo: really, it's not clear why this might occur, as 
-    ** wal_autocheckpoint ought to be turned off.  */
+  if( pRbu && (
+       pRbu->eStage==RBU_STAGE_OAL 
+    || pRbu->eStage==RBU_STAGE_MOVE 
+    || pRbu->eStage==RBU_STAGE_DONE
+  )){
+    /* Prevent SQLite from taking a shm-lock on the target file when it 
+    ** is supplying heap memory to the upper layer in place of *-shm 
+    ** segments. */
    if( ofst==WAL_LOCK_CKPT && n==1 ) rc = SQLITE_BUSY;
  }else{
    int bCapture = 0;
    if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){
      bCapture = 1;
    }
-
    if( bCapture==0 || 0==(flags & SQLITE_SHM_UNLOCK) ){
      rc = p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);
      if( bCapture && rc==SQLITE_OK ){
-        pRbu->mLock |= (1 << ofst);
+        pRbu->mLock |= ((1<<n) - 1) << ofst;
      }
    }
  }
@@ -473,7 +473,7 @@ static int cidxLookupIndex(
    
  /* Find the table for this index. */
  pFindTab = cidxPrepare(&rc, pCsr, 
-      "SELECT tbl_name, sql FROM sqlite_master WHERE name=%Q AND type='index'",
+      "SELECT tbl_name, sql FROM sqlite_schema WHERE name=%Q AND type='index'",
      zIdx
  );
  if( rc==SQLITE_OK && sqlite3_step(pFindTab)==SQLITE_ROW ){
@@ -683,6 +683,8 @@ static GeoPoly *geopolyBBox(
      aCoord[2].f = mnY;
      aCoord[3].f = mxY;
    }
+  }else{
+    memset(aCoord, 0, sizeof(RtreeCoord)*4);
  }
  return pOut;
 }
@@ -1073,7 +1075,7 @@ static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2){
  geopolyAddSegments(p, p1, 1);
  geopolyAddSegments(p, p2, 2);
  pThisEvent = geopolySortEventsByX(p->aEvent, p->nEvent);
-  rX = pThisEvent->x==0.0 ? -1.0 : 0.0;
+  rX = pThisEvent && pThisEvent->x==0.0 ? -1.0 : 0.0;
  memset(aOverlap, 0, sizeof(aOverlap));
  while( pThisEvent ){
    if( pThisEvent->x!=rX ){
@@ -82,6 +82,7 @@ typedef unsigned int u32;
 #include <string.h>
 #include <stdio.h>
 #include <assert.h>
+#include <stdlib.h>

 /*  The following macro is used to suppress compiler warnings.
 */
@@ -419,6 +420,23 @@ struct RtreeMatchArg {
 # define testcase(X)
 #endif

+/*
+** Make sure that the compiler intrinsics we desire are enabled when
+** compiling with an appropriate version of MSVC unless prevented by
+** the SQLITE_DISABLE_INTRINSIC define.
+*/
+#if !defined(SQLITE_DISABLE_INTRINSIC)
+#  if defined(_MSC_VER) && _MSC_VER>=1400
+#    if !defined(_WIN32_WCE)
+#      include <intrin.h>
+#      pragma intrinsic(_byteswap_ulong)
+#      pragma intrinsic(_byteswap_uint64)
+#    else
+#      include <cmnintrin.h>
+#    endif
+#  endif
+#endif
+
 /*
 ** Macros to determine whether the machine is big or little endian,
 ** and whether or not that determination is run-time or compile-time.
@@ -741,7 +759,7 @@ static int nodeAcquire(
  ** are the leaves, and so on. If the depth as specified on the root node
  ** is greater than RTREE_MAX_DEPTH, the r-tree structure must be corrupt.
  */
-  if( pNode && iNode==1 ){
+  if( pNode && rc==SQLITE_OK && iNode==1 ){
    pRtree->iDepth = readInt16(pNode->zData);
    if( pRtree->iDepth>RTREE_MAX_DEPTH ){
      rc = SQLITE_CORRUPT_VTAB;
@@ -35,7 +35,7 @@ proc test_reset {} {

 test_reset
 do_execsql_test 1.0 { 
-  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t1(a INT PRIMARY KEY, b);
  INSERT INTO t1 VALUES('i', 'one');
 }
 do_iterator_test 1.1 t1 {
@@ -184,7 +184,7 @@ set set_of_tests {

 test_reset
 do_common_sql {
-  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t1(a int PRIMARY KEY, b);
  CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
  CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
  CREATE TABLE t4(a, b, PRIMARY KEY(b, a));
@@ -206,17 +206,17 @@ sqlite3 db3 test.db3
 do_test 3.0 {
  execsql {
    ATTACH 'test.db3' AS 'aux';
-    CREATE TABLE t1(a, b PRIMARY KEY);
+    CREATE TABLE t1(a int, b PRIMARY KEY);
    CREATE TABLE t2(x, y, z);
    CREATE TABLE t3(a);

-    CREATE TABLE aux.t1(a PRIMARY KEY, b);
+    CREATE TABLE aux.t1(a int PRIMARY KEY, b);
    CREATE TABLE aux.t2(a, b INTEGER PRIMARY KEY);
    CREATE TABLE aux.t3(a, b, c, PRIMARY KEY(a, b));
    CREATE TABLE aux.t4(a, b, PRIMARY KEY(b, a));
  }
  execsql {
-    CREATE TABLE t1(a PRIMARY KEY, b);
+    CREATE TABLE t1(a int PRIMARY KEY, b);
    CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
    CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
    CREATE TABLE t4(a, b, PRIMARY KEY(b, a));
@@ -588,4 +588,52 @@ do_execsql_test 10.2 {
 } {0 0 1 1}
 S delete

+#-------------------------------------------------------------------------
+test_reset
+do_common_sql {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c, d, e, f);
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<32
+  )
+  INSERT INTO t1 SELECT NULL, 0, 0, 0, 0, 0 FROM s
+}
+
+do_then_apply_sql {
+  UPDATE t1 SET                             f=f+1 WHERE a=1;
+  UPDATE t1 SET                      e=e+1        WHERE a=2;
+  UPDATE t1 SET                      e=e+1, f=f+1 WHERE a=3;
+  UPDATE t1 SET               d=d+1               WHERE a=4;
+  UPDATE t1 SET               d=d+1,        f=f+1 WHERE a=5;
+  UPDATE t1 SET               d=d+1, e=e+1        WHERE a=6;
+  UPDATE t1 SET               d=d+1, e=e+1, f=f+1 WHERE a=7;
+  UPDATE t1 SET        c=c+1                      WHERE a=8;
+  UPDATE t1 SET        c=c+1,               f=f+1 WHERE a=9;
+  UPDATE t1 SET        c=c+1,        e=e+1        WHERE a=10;
+  UPDATE t1 SET        c=c+1,        e=e+1, f=f+1 WHERE a=11;
+  UPDATE t1 SET        c=c+1, d=d+1               WHERE a=12;
+  UPDATE t1 SET        c=c+1, d=d+1,        f=f+1 WHERE a=13;
+  UPDATE t1 SET        c=c+1, d=d+1, e=e+1        WHERE a=14;
+  UPDATE t1 SET        c=c+1, d=d+1, e=e+1, f=f+1 WHERE a=15;
+  UPDATE t1 SET d=d+1                             WHERE a=16;
+  UPDATE t1 SET d=d+1,                      f=f+1 WHERE a=17;
+  UPDATE t1 SET d=d+1,               e=e+1        WHERE a=18;
+  UPDATE t1 SET d=d+1,               e=e+1, f=f+1 WHERE a=19;
+  UPDATE t1 SET d=d+1,        d=d+1               WHERE a=20;
+  UPDATE t1 SET d=d+1,        d=d+1,        f=f+1 WHERE a=21;
+  UPDATE t1 SET d=d+1,        d=d+1, e=e+1        WHERE a=22;
+  UPDATE t1 SET d=d+1,        d=d+1, e=e+1, f=f+1 WHERE a=23;
+  UPDATE t1 SET d=d+1, c=c+1                      WHERE a=24;
+  UPDATE t1 SET d=d+1, c=c+1,               f=f+1 WHERE a=25;
+  UPDATE t1 SET d=d+1, c=c+1,        e=e+1        WHERE a=26;
+  UPDATE t1 SET d=d+1, c=c+1,        e=e+1, f=f+1 WHERE a=27;
+  UPDATE t1 SET d=d+1, c=c+1, d=d+1               WHERE a=28;
+  UPDATE t1 SET d=d+1, c=c+1, d=d+1,        f=f+1 WHERE a=29;
+  UPDATE t1 SET d=d+1, c=c+1, d=d+1, e=e+1        WHERE a=30;
+  UPDATE t1 SET d=d+1, c=c+1, d=d+1, e=e+1, f=f+1 WHERE a=31;
+}
+
+do_test 11.0 {
+  compare_db db db2
+} {}
+
 finish_test
@@ -172,8 +172,8 @@ proc compare_db {db1 db2} {
    set data1 [$db1 eval $sql]
    set data2 [$db2 eval $sql]
    if {$data1 != $data2} { 
-      puts "$data1"
-      puts "$data2"
+      puts "$db1: $data1"
+      puts "$db2: $data2"
      error "table $tbl data mismatch" 
    }
  }
@@ -155,5 +155,29 @@ do_test 3.2 {
  compare_db db db2
 } {}

+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 4.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b UNIQUE);
+  INSERT INTO t1 VALUES(1, 'one');
+  INSERT INTO t1 VALUES(2, 'two');
+  INSERT INTO t1 VALUES(3, 'three');
+  INSERT INTO t1 VALUES(4, 'four');
+}
+
+do_invert_test 4.1 {
+  DELETE FROM t1;
+  INSERT INTO t1 VALUES(1, 'two');
+  INSERT INTO t1 VALUES(2, 'five');
+  INSERT INTO t1 VALUES(3, 'one');
+  INSERT INTO t1 VALUES(4, 'three');
+} {
+  {UPDATE t1 0 X. {i 1 t two} {{} {} t one}}
+  {UPDATE t1 0 X. {i 2 t five} {{} {} t two}}
+  {UPDATE t1 0 X. {i 3 t one} {{} {} t three}} 
+  {UPDATE t1 0 X. {i 4 t three} {{} {} t four}}
+}
+

 finish_test
@@ -0,0 +1,57 @@
+# 2020 December 23
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for the SQLite sessions module
+# Specifically, for the sqlite3session_memory_used() API.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix sessionmem
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(i INTEGER PRIMARY KEY, x, y);
+  CREATE TABLE t2(i INTEGER, x, y, PRIMARY KEY(x, y));
+}
+
+do_test 1.1 {
+  sqlite3session S db main
+  S attach *
+} {}
+
+foreach {tn sql eRes} {
+  1 { INSERT INTO t1 VALUES(1, 2, 3) } 1
+  2 { UPDATE t1 SET x=5 }                    0
+  3 { UPDATE t1 SET i=5 }                    1
+  4 { DELETE FROM t1 }                       0
+  5 { INSERT INTO t1 VALUES(1, 2, 3) }       0
+  6 { INSERT INTO t1 VALUES(5, 2, 3) }       0
+  7 { INSERT INTO t2 VALUES('a', 'b', 'c') } 1
+  8 { INSERT INTO t2 VALUES('d', 'e', 'f') } 1
+  9 { UPDATE t2 SET i='e' }                  0
+} {
+  set mem1 [S memory_used]
+  do_test 1.2.$tn.(mu=$mem1) {
+    execsql $sql
+    set mem2 [S memory_used]
+    expr {$mem2 > $mem1}
+  } $eRes
+}
+
+do_test 1.3 {
+  S delete
+} {}
+
+finish_test
@@ -0,0 +1,187 @@
+# 2021 Februar 20
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix sessionnoop
+
+#-------------------------------------------------------------------------
+# Test plan:
+#
+#   1.*: Test that concatenating changesets cannot produce a noop UPDATE.
+#   2.*: Test that rebasing changesets cannot produce a noop UPDATE.
+#   3.*: Test that sqlite3changeset_apply() ignores noop UPDATE changes.
+#
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c, d);
+  INSERT INTO t1 VALUES(1, 1, 1, 1);
+  INSERT INTO t1 VALUES(2, 2, 2, 2);
+  INSERT INTO t1 VALUES(3, 3, 3, 3);
+}
+
+proc do_concat_test {tn sql1 sql2 res} {
+  uplevel [list do_test $tn [subst -nocommands {
+    set C1 [changeset_from_sql {$sql1}]
+    set C2 [changeset_from_sql {$sql2}]
+    set C3 [sqlite3changeset_concat [set C1] [set C2]]
+    set got [list]
+    sqlite3session_foreach elem [set C3] { lappend got [set elem] }
+    set got
+  }] [list {*}$res]]
+}
+
+do_concat_test 1.1 {
+  UPDATE t1 SET c=c+1;
+} {
+  UPDATE t1 SET c=c-1;
+} {
+}
+
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c);
+  INSERT INTO t1 VALUES(1, 1, 1);
+  INSERT INTO t1 VALUES(2, 2, 2);
+  INSERT INTO t1 VALUES(3, 3, 3);
+}
+
+proc do_rebase_test {tn sql_local sql_remote conflict_res expected} {
+  proc xConflict {args} [list return $conflict_res]
+
+  uplevel [list \
+    do_test $tn [subst -nocommands {
+      execsql BEGIN
+        set c_remote [changeset_from_sql {$sql_remote}]
+      execsql ROLLBACK
+
+      execsql BEGIN
+        set c_local [changeset_from_sql {$sql_local}]
+        set base [sqlite3changeset_apply_v2 db [set c_remote] xConflict]
+      execsql ROLLBACK
+
+      sqlite3rebaser_create R
+      R config [set base]
+      set res [list]
+      sqlite3session_foreach elem [R rebase [set c_local]] { 
+        lappend res [set elem] 
+      }
+      R delete
+      set res
+    }] [list {*}$expected]
+  ]
+}
+
+do_rebase_test 2.1 {
+  UPDATE t1 SET c=2 WHERE a=1;              -- local
+} {
+  UPDATE t1 SET c=3 WHERE a=1;              -- remote
+} OMIT {
+  {UPDATE t1 0 X.. {i 1 {} {} i 3} {{} {} {} {} i 2}}
+}
+
+do_rebase_test 2.2 {
+  UPDATE t1 SET c=2 WHERE a=1;              -- local
+} {
+  UPDATE t1 SET c=3 WHERE a=1;              -- remote
+} REPLACE {
+}
+
+do_rebase_test 2.3.1 {
+  UPDATE t1 SET c=4 WHERE a=1;              -- local
+} {
+  UPDATE t1 SET c=4 WHERE a=1               -- remote
+} OMIT {
+  {UPDATE t1 0 X.. {i 1 {} {} i 4} {{} {} {} {} i 4}}
+}
+
+do_rebase_test 2.3.2 {
+  UPDATE t1 SET c=5 WHERE a=1;              -- local
+} {
+  UPDATE t1 SET c=5 WHERE a=1               -- remote
+} REPLACE {
+}
+
+#-------------------------------------------------------------------------
+#
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
+  INSERT INTO t1 VALUES(1, 1, 1);
+  INSERT INTO t1 VALUES(2, 2, 2);
+  INSERT INTO t1 VALUES(3, 3, 3);
+  INSERT INTO t1 VALUES(4, 4, 4);
+}
+
+# Arg $pkstr contains one character for each column in the table. An
+# "X" for PK column, or a "." for a non-PK.
+#
+proc mk_tbl_header {name pkstr} {
+  set ret [binary format H2c 54 [string length $pkstr]]
+  foreach i [split $pkstr {}] {
+    if {$i=="X"} {
+      append ret [binary format H2 01]
+    } else {
+      if {$i!="."} {error "bad pkstr: $pkstr ($i)"}
+      append ret [binary format H2 00]
+    }
+  }
+  append ret $name
+  append ret [binary format H2 00]
+  set ret
+}
+
+proc mk_update_change {args} {
+  set ret [binary format H2H2 17 00]
+  foreach a $args {
+    if {$a==""} {
+      append ret [binary format H2 00]
+    } else {
+      append ret [binary format H2W 01 $a]
+    }
+  }
+  set ret
+}
+
+proc xConflict {args} { return "ABORT" }
+do_test 3.1 {
+  set    C [mk_tbl_header t1 X..]
+  append C [mk_update_change    1 {} 1   {} {}  500]
+  append C [mk_update_change    2 {} {}  {} {}  {}]
+  append C [mk_update_change    3 3  {}  {} 600 {}]
+  append C [mk_update_change    4 {} {}  {} {}  {}]
+
+  sqlite3changeset_apply_v2 db $C xConflict
+} {}
+do_execsql_test 3.2 {
+  SELECT * FROM t1
+} {
+  1 1 500
+  2 2 2
+  3 600 3
+  4 4 4
+}
+
+
+
+
+
+
+finish_test
+
@@ -69,7 +69,9 @@ foreach {tn wo} {
 } {
  reset_db

-  do_execsql_test 2.$tn.0 "CREATE TABLE t1(a INTEGER PRIMARY KEY, b) $wo ;"
+  do_execsql_test 2.$tn.0.1 "CREATE TABLE t1(a INTEGER PRIMARY KEY, b) $wo ;"
+  do_execsql_test 2.$tn.0.2 "CREATE TABLE t2(a INTEGER PRIMARY KEY, b) $wo ;"
+  do_execsql_test 2.$tn.0.3 "CREATE TABLE t3(a INTEGER PRIMARY KEY, b) $wo ;"
  
  do_iterator_test 1.1 t1 {
    INSERT INTO t1 VALUES(1, 'two');
@@ -94,6 +96,27 @@ foreach {tn wo} {
  } {
    {DELETE t1 0 X. {i 1 t four} {}}
  }
+
+  do_execsql_test 2.$tn.5 {
+    INSERT INTO t1 VALUES(1, 'one');
+    INSERT INTO t1 VALUES(2, 'two');
+    INSERT INTO t1 VALUES(3, 'three');
+  }
+
+  do_iterator_test 2.$tn.6 t2 {
+    INSERT INTO t2 SELECT a, b FROM t1
+  } {
+    {INSERT t2 0 X. {} {i 1 t one}} 
+    {INSERT t2 0 X. {} {i 2 t two}}
+    {INSERT t2 0 X. {} {i 3 t three}}
+  }
+  do_iterator_test 2.$tn.7 t3 {
+    INSERT INTO t3 SELECT * FROM t1
+  } {
+    {INSERT t3 0 X. {} {i 1 t one}} 
+    {INSERT t3 0 X. {} {i 2 t two}}
+    {INSERT t3 0 X. {} {i 3 t three}}
+  }
 }

 finish_test
@@ -48,6 +48,7 @@ struct sqlite3_session {
  int rc;                         /* Non-zero if an error has occurred */
  void *pFilterCtx;               /* First argument to pass to xTableFilter */
  int (*xTableFilter)(void *pCtx, const char *zTab);
+  i64 nMalloc;                    /* Number of bytes of data allocated */
  sqlite3_value *pZeroBlob;       /* Value containing X'' */
  sqlite3_session *pNext;         /* Next session object on same db. */
  SessionTable *pTable;           /* List of attached tables */
@@ -90,6 +91,7 @@ struct sqlite3_changeset_iter {
  SessionBuffer tblhdr;           /* Buffer to hold apValue/zTab/abPK/ */
  int bPatchset;                  /* True if this is a patchset */
  int bInvert;                    /* True to invert changeset */
+  int bSkipEmpty;                 /* Skip noop UPDATE changes */
  int rc;                         /* Iterator error code */
  sqlite3_stmt *pConflict;        /* Points to conflicting row, if any */
  char *zTab;                     /* Current table */
@@ -431,6 +433,26 @@ static int sessionSerializeValue(
  return SQLITE_OK;
 }

+/*
+** Allocate and return a pointer to a buffer nByte bytes in size. If
+** pSession is not NULL, increase the sqlite3_session.nMalloc variable
+** by the number of bytes allocated.
+*/
+static void *sessionMalloc64(sqlite3_session *pSession, i64 nByte){
+  void *pRet = sqlite3_malloc64(nByte);
+  if( pSession ) pSession->nMalloc += sqlite3_msize(pRet);
+  return pRet;
+}
+
+/*
+** Free buffer pFree, which must have been allocated by an earlier
+** call to sessionMalloc64(). If pSession is not NULL, decrease the
+** sqlite3_session.nMalloc counter by the number of bytes freed.
+*/
+static void sessionFree(sqlite3_session *pSession, void *pFree){
+  if( pSession ) pSession->nMalloc -= sqlite3_msize(pFree);
+  sqlite3_free(pFree);
+}

 /*
 ** This macro is used to calculate hash key values for data structures. In
@@ -898,13 +920,19 @@ static int sessionPreupdateEqual(
 ** Growing the hash table in this case is a performance optimization only,
 ** it is not required for correct operation.
 */
-static int sessionGrowHash(int bPatchset, SessionTable *pTab){
+static int sessionGrowHash(
+  sqlite3_session *pSession,      /* For memory accounting. May be NULL */
+  int bPatchset, 
+  SessionTable *pTab
+){
  if( pTab->nChange==0 || pTab->nEntry>=(pTab->nChange/2) ){
    int i;
    SessionChange **apNew;
    sqlite3_int64 nNew = 2*(sqlite3_int64)(pTab->nChange ? pTab->nChange : 128);

-    apNew = (SessionChange **)sqlite3_malloc64(sizeof(SessionChange *) * nNew);
+    apNew = (SessionChange**)sessionMalloc64(
+        pSession, sizeof(SessionChange*) * nNew
+    );
    if( apNew==0 ){
      if( pTab->nChange==0 ){
        return SQLITE_ERROR;
@@ -925,7 +953,7 @@ static int sessionGrowHash(int bPatchset, SessionTable *pTab){
      }
    }

-    sqlite3_free(pTab->apChange);
+    sessionFree(pSession, pTab->apChange);
    pTab->nChange = nNew;
    pTab->apChange = apNew;
  }
@@ -959,6 +987,7 @@ static int sessionGrowHash(int bPatchset, SessionTable *pTab){
 ** be freed using sqlite3_free() by the caller
 */
 static int sessionTableInfo(
+  sqlite3_session *pSession,      /* For memory accounting. May be NULL */
  sqlite3 *db,                    /* Database connection */
  const char *zDb,                /* Name of attached database (e.g. "main") */
  const char *zThis,              /* Table name */
@@ -1013,7 +1042,7 @@ static int sessionTableInfo(

  if( rc==SQLITE_OK ){
    nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1);
-    pAlloc = sqlite3_malloc64(nByte);
+    pAlloc = sessionMalloc64(pSession, nByte);
    if( pAlloc==0 ){
      rc = SQLITE_NOMEM;
    }
@@ -1056,7 +1085,7 @@ static int sessionTableInfo(
    *pabPK = 0;
    *pnCol = 0;
    if( pzTab ) *pzTab = 0;
-    sqlite3_free(azCol);
+    sessionFree(pSession, azCol);
  }
  sqlite3_finalize(pStmt);
  return rc;
@@ -1078,7 +1107,7 @@ static int sessionInitTable(sqlite3_session *pSession, SessionTable *pTab){
  if( pTab->nCol==0 ){
    u8 *abPK;
    assert( pTab->azCol==0 || pTab->abPK==0 );
-    pSession->rc = sessionTableInfo(pSession->db, pSession->zDb, 
+    pSession->rc = sessionTableInfo(pSession, pSession->db, pSession->zDb, 
        pTab->zName, &pTab->nCol, 0, &pTab->azCol, &abPK
    );
    if( pSession->rc==SQLITE_OK ){
@@ -1169,7 +1198,7 @@ static void sessionPreupdateOneChange(
  }

  /* Grow the hash table if required */
-  if( sessionGrowHash(0, pTab) ){
+  if( sessionGrowHash(pSession, 0, pTab) ){
    pSession->rc = SQLITE_NOMEM;
    return;
  }
@@ -1236,7 +1265,7 @@ static void sessionPreupdateOneChange(
      }
  
      /* Allocate the change object */
-      pChange = (SessionChange *)sqlite3_malloc64(nByte);
+      pChange = (SessionChange *)sessionMalloc64(pSession, nByte);
      if( !pChange ){
        rc = SQLITE_NOMEM;
        goto error_out;
@@ -1609,7 +1638,7 @@ int sqlite3session_diff(
      int nCol;                   /* Columns in zFrom.zTbl */
      u8 *abPK;
      const char **azCol = 0;
-      rc = sessionTableInfo(db, zFrom, zTbl, &nCol, 0, &azCol, &abPK);
+      rc = sessionTableInfo(0, db, zFrom, zTbl, &nCol, 0, &azCol, &abPK);
      if( rc==SQLITE_OK ){
        if( pTo->nCol!=nCol ){
          bMismatch = 1;
@@ -1707,7 +1736,7 @@ int sqlite3session_create(
 ** Free the list of table objects passed as the first argument. The contents
 ** of the changed-rows hash tables are also deleted.
 */
-static void sessionDeleteTable(SessionTable *pList){
+static void sessionDeleteTable(sqlite3_session *pSession, SessionTable *pList){
  SessionTable *pNext;
  SessionTable *pTab;

@@ -1719,12 +1748,12 @@ static void sessionDeleteTable(SessionTable *pList){
      SessionChange *pNextChange;
      for(p=pTab->apChange[i]; p; p=pNextChange){
        pNextChange = p->pNext;
-        sqlite3_free(p);
+        sessionFree(pSession, p);
      }
    }
-    sqlite3_free((char*)pTab->azCol);  /* cast works around VC++ bug */
-    sqlite3_free(pTab->apChange);
-    sqlite3_free(pTab);
+    sessionFree(pSession, (char*)pTab->azCol);  /* cast works around VC++ bug */
+    sessionFree(pSession, pTab->apChange);
+    sessionFree(pSession, pTab);
  }
 }

@@ -1752,9 +1781,11 @@ void sqlite3session_delete(sqlite3_session *pSession){

  /* Delete all attached table objects. And the contents of their 
  ** associated hash-tables. */
-  sessionDeleteTable(pSession->pTable);
+  sessionDeleteTable(pSession, pSession->pTable);

-  /* Free the session object itself. */
+  /* Assert that all allocations have been freed and then free the 
+  ** session object itself. */
+  assert( pSession->nMalloc==0 );
  sqlite3_free(pSession);
 }

@@ -1801,7 +1832,8 @@ int sqlite3session_attach(

    if( !pTab ){
      /* Allocate new SessionTable object. */
-      pTab = (SessionTable *)sqlite3_malloc64(sizeof(SessionTable) + nName + 1);
+      int nByte = sizeof(SessionTable) + nName + 1;
+      pTab = (SessionTable*)sessionMalloc64(pSession, nByte);
      if( !pTab ){
        rc = SQLITE_NOMEM;
      }else{
@@ -2398,7 +2430,7 @@ static int sessionGenerateChangeset(
      int nNoop;                  /* Size of buffer after writing tbl header */

      /* Check the table schema is still Ok. */
-      rc = sessionTableInfo(db, pSession->zDb, zName, &nCol, 0, &azCol, &abPK);
+      rc = sessionTableInfo(0, db, pSession->zDb, zName, &nCol, 0,&azCol,&abPK);
      if( !rc && (pTab->nCol!=nCol || memcmp(abPK, pTab->abPK, nCol)) ){
        rc = SQLITE_SCHEMA;
      }
@@ -2573,6 +2605,13 @@ int sqlite3session_isempty(sqlite3_session *pSession){
  return (ret==0);
 }

+/*
+** Return the amount of heap memory in use.
+*/
+sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession){
+  return pSession->nMalloc;
+}
+
 /*
 ** Do the work for either sqlite3changeset_start() or start_strm().
 */
@@ -2582,7 +2621,8 @@ static int sessionChangesetStart(
  void *pIn,
  int nChangeset,                 /* Size of buffer pChangeset in bytes */
  void *pChangeset,               /* Pointer to buffer containing changeset */
-  int bInvert                     /* True to invert changeset */
+  int bInvert,                    /* True to invert changeset */
+  int bSkipEmpty                  /* True to skip empty UPDATE changes */
 ){
  sqlite3_changeset_iter *pRet;   /* Iterator to return */
  int nByte;                      /* Number of bytes to allocate for iterator */
@@ -2603,6 +2643,7 @@ static int sessionChangesetStart(
  pRet->in.pIn = pIn;
  pRet->in.bEof = (xInput ? 0 : 1);
  pRet->bInvert = bInvert;
+  pRet->bSkipEmpty = bSkipEmpty;

  /* Populate the output variable and return success. */
  *pp = pRet;
@@ -2617,7 +2658,7 @@ int sqlite3changeset_start(
  int nChangeset,                 /* Size of buffer pChangeset in bytes */
  void *pChangeset                /* Pointer to buffer containing changeset */
 ){
-  return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, 0);
+  return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, 0, 0);
 }
 int sqlite3changeset_start_v2(
  sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */
@@ -2626,7 +2667,7 @@ int sqlite3changeset_start_v2(
  int flags
 ){
  int bInvert = !!(flags & SQLITE_CHANGESETSTART_INVERT);
-  return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, bInvert);
+  return sessionChangesetStart(pp, 0, 0, nChangeset, pChangeset, bInvert, 0);
 }

 /*
@@ -2637,7 +2678,7 @@ int sqlite3changeset_start_strm(
  int (*xInput)(void *pIn, void *pData, int *pnData),
  void *pIn
 ){
-  return sessionChangesetStart(pp, xInput, pIn, 0, 0, 0);
+  return sessionChangesetStart(pp, xInput, pIn, 0, 0, 0, 0);
 }
 int sqlite3changeset_start_v2_strm(
  sqlite3_changeset_iter **pp,    /* OUT: Changeset iterator handle */
@@ -2646,7 +2687,7 @@ int sqlite3changeset_start_v2_strm(
  int flags
 ){
  int bInvert = !!(flags & SQLITE_CHANGESETSTART_INVERT);
-  return sessionChangesetStart(pp, xInput, pIn, 0, 0, bInvert);
+  return sessionChangesetStart(pp, xInput, pIn, 0, 0, bInvert, 0);
 }

 /*
@@ -2772,11 +2813,14 @@ static int sessionReadRecord(
  SessionInput *pIn,              /* Input data */
  int nCol,                       /* Number of values in record */
  u8 *abPK,                       /* Array of primary key flags, or NULL */
-  sqlite3_value **apOut           /* Write values to this array */
+  sqlite3_value **apOut,          /* Write values to this array */
+  int *pbEmpty
 ){
  int i;                          /* Used to iterate through columns */
  int rc = SQLITE_OK;

+  assert( pbEmpty==0 || *pbEmpty==0 );
+  if( pbEmpty ) *pbEmpty = 1;
  for(i=0; i<nCol && rc==SQLITE_OK; i++){
    int eType = 0;                /* Type of value (SQLITE_NULL, TEXT etc.) */
    if( abPK && abPK[i]==0 ) continue;
@@ -2788,6 +2832,7 @@ static int sessionReadRecord(
        eType = pIn->aData[pIn->iNext++];
        assert( apOut[i]==0 );
        if( eType ){
+          if( pbEmpty ) *pbEmpty = 0;
          apOut[i] = sqlite3ValueNew(0);
          if( !apOut[i] ) rc = SQLITE_NOMEM;
        }
@@ -2956,37 +3001,38 @@ static int sessionChangesetReadTblhdr(sqlite3_changeset_iter *p){
  }

  p->apValue = (sqlite3_value**)p->tblhdr.aBuf;
-  p->abPK = (u8*)&p->apValue[p->nCol*2];
-  p->zTab = (char*)&p->abPK[p->nCol];
+  if( p->apValue==0 ){
+    p->abPK = 0;
+    p->zTab = 0;
+  }else{
+    p->abPK = (u8*)&p->apValue[p->nCol*2];
+    p->zTab = p->abPK ? (char*)&p->abPK[p->nCol] : 0;
+  }
  return (p->rc = rc);
 }

 /*
-** Advance the changeset iterator to the next change.
+** Advance the changeset iterator to the next change. The differences between
+** this function and sessionChangesetNext() are that
 **
-** If both paRec and pnRec are NULL, then this function works like the public
-** API sqlite3changeset_next(). If SQLITE_ROW is returned, then the
-** sqlite3changeset_new() and old() APIs may be used to query for values.
+**   * If pbEmpty is not NULL and the change is a no-op UPDATE (an UPDATE
+**     that modifies no columns), this function sets (*pbEmpty) to 1.
 **
-** Otherwise, if paRec and pnRec are not NULL, then a pointer to the change
-** record is written to *paRec before returning and the number of bytes in
-** the record to *pnRec.
-**
-** Either way, this function returns SQLITE_ROW if the iterator is 
-** successfully advanced to the next change in the changeset, an SQLite 
-** error code if an error occurs, or SQLITE_DONE if there are no further 
-** changes in the changeset.
+**   * If the iterator is configured to skip no-op UPDATEs,
+**     sessionChangesetNext() does that. This function does not.
 */
-static int sessionChangesetNext(
+static int sessionChangesetNextOne(
  sqlite3_changeset_iter *p,      /* Changeset iterator */
  u8 **paRec,                     /* If non-NULL, store record pointer here */
  int *pnRec,                     /* If non-NULL, store size of record here */
-  int *pbNew                      /* If non-NULL, true if new table */
+  int *pbNew,                     /* If non-NULL, true if new table */
+  int *pbEmpty
 ){
  int i;
  u8 op;

  assert( (paRec==0 && pnRec==0) || (paRec && pnRec) );
+  assert( pbEmpty==0 || *pbEmpty==0 );

  /* If the iterator is in the error-state, return immediately. */
  if( p->rc!=SQLITE_OK ) return p->rc;
@@ -3059,13 +3105,13 @@ static int sessionChangesetNext(
    /* If this is an UPDATE or DELETE, read the old.* record. */
    if( p->op!=SQLITE_INSERT && (p->bPatchset==0 || p->op==SQLITE_DELETE) ){
      u8 *abPK = p->bPatchset ? p->abPK : 0;
-      p->rc = sessionReadRecord(&p->in, p->nCol, abPK, apOld);
+      p->rc = sessionReadRecord(&p->in, p->nCol, abPK, apOld, 0);
      if( p->rc!=SQLITE_OK ) return p->rc;
    }

    /* If this is an INSERT or UPDATE, read the new.* record. */
    if( p->op!=SQLITE_DELETE ){
-      p->rc = sessionReadRecord(&p->in, p->nCol, 0, apNew);
+      p->rc = sessionReadRecord(&p->in, p->nCol, 0, apNew, pbEmpty);
      if( p->rc!=SQLITE_OK ) return p->rc;
    }

@@ -3092,6 +3138,37 @@ static int sessionChangesetNext(
  return SQLITE_ROW;
 }

+/*
+** Advance the changeset iterator to the next change.
+**
+** If both paRec and pnRec are NULL, then this function works like the public
+** API sqlite3changeset_next(). If SQLITE_ROW is returned, then the
+** sqlite3changeset_new() and old() APIs may be used to query for values.
+**
+** Otherwise, if paRec and pnRec are not NULL, then a pointer to the change
+** record is written to *paRec before returning and the number of bytes in
+** the record to *pnRec.
+**
+** Either way, this function returns SQLITE_ROW if the iterator is 
+** successfully advanced to the next change in the changeset, an SQLite 
+** error code if an error occurs, or SQLITE_DONE if there are no further 
+** changes in the changeset.
+*/
+static int sessionChangesetNext(
+  sqlite3_changeset_iter *p,      /* Changeset iterator */
+  u8 **paRec,                     /* If non-NULL, store record pointer here */
+  int *pnRec,                     /* If non-NULL, store size of record here */
+  int *pbNew                      /* If non-NULL, true if new table */
+){
+  int bEmpty;
+  int rc;
+  do {
+    bEmpty = 0;
+    rc = sessionChangesetNextOne(p, paRec, pnRec, pbNew, &bEmpty);
+  }while( rc==SQLITE_ROW && p->bSkipEmpty && bEmpty);
+  return rc;
+}
+
 /*
 ** Advance an iterator created by sqlite3changeset_start() to the next
 ** change in the changeset. This function may return SQLITE_ROW, SQLITE_DONE
@@ -3364,9 +3441,9 @@ static int sessionChangesetInvert(

        /* Read the old.* and new.* records for the update change. */
        pInput->iNext += 2;
-        rc = sessionReadRecord(pInput, nCol, 0, &apVal[0]);
+        rc = sessionReadRecord(pInput, nCol, 0, &apVal[0], 0);
        if( rc==SQLITE_OK ){
-          rc = sessionReadRecord(pInput, nCol, 0, &apVal[nCol]);
+          rc = sessionReadRecord(pInput, nCol, 0, &apVal[nCol], 0);
        }

        /* Write the new old.* record. Consists of the PK columns from the
@@ -3467,24 +3544,195 @@ int sqlite3changeset_invert_strm(
  return rc;
 }

+
+typedef struct SessionUpdate SessionUpdate;
+struct SessionUpdate {
+  sqlite3_stmt *pStmt;
+  u32 *aMask;
+  SessionUpdate *pNext;
+};
+
 typedef struct SessionApplyCtx SessionApplyCtx;
 struct SessionApplyCtx {
  sqlite3 *db;
  sqlite3_stmt *pDelete;          /* DELETE statement */
-  sqlite3_stmt *pUpdate;          /* UPDATE statement */
  sqlite3_stmt *pInsert;          /* INSERT statement */
  sqlite3_stmt *pSelect;          /* SELECT statement */
  int nCol;                       /* Size of azCol[] and abPK[] arrays */
  const char **azCol;             /* Array of column names */
  u8 *abPK;                       /* Boolean array - true if column is in PK */
+  u32 *aUpdateMask;               /* Used by sessionUpdateFind */
+  SessionUpdate *pUp;
  int bStat1;                     /* True if table is sqlite_stat1 */
  int bDeferConstraints;          /* True to defer constraints */
+  int bInvertConstraints;         /* Invert when iterating constraints buffer */
  SessionBuffer constraints;      /* Deferred constraints are stored here */
  SessionBuffer rebase;           /* Rebase information (if any) here */
  u8 bRebaseStarted;              /* If table header is already in rebase */
  u8 bRebase;                     /* True to collect rebase information */
 };

+/* Number of prepared UPDATE statements to cache. */
+#define SESSION_UPDATE_CACHE_SZ 12
+
+/*
+** Find a prepared UPDATE statement suitable for the UPDATE step currently
+** being visited by the iterator. The UPDATE is of the form:
+**
+**   UPDATE tbl SET col = ?, col2 = ? WHERE pk1 IS ? AND pk2 IS ?
+*/
+static int sessionUpdateFind(
+  sqlite3_changeset_iter *pIter,
+  SessionApplyCtx *p,
+  int bPatchset,
+  sqlite3_stmt **ppStmt
+){
+  int rc = SQLITE_OK;
+  SessionUpdate *pUp = 0;
+  int nCol = pIter->nCol;
+  int nU32 = (pIter->nCol+33)/32;
+  int ii;
+
+  if( p->aUpdateMask==0 ){
+    p->aUpdateMask = sqlite3_malloc(nU32*sizeof(u32));
+    if( p->aUpdateMask==0 ){
+      rc = SQLITE_NOMEM;
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    memset(p->aUpdateMask, 0, nU32*sizeof(u32));
+    rc = SQLITE_CORRUPT;
+    for(ii=0; ii<pIter->nCol; ii++){
+      if( sessionChangesetNew(pIter, ii) ){
+        p->aUpdateMask[ii/32] |= (1<<(ii%32));
+        rc = SQLITE_OK;
+      }
+    }
+  }
+
+  if( rc==SQLITE_OK ){
+    if( bPatchset ) p->aUpdateMask[nCol/32] |= (1<<(nCol%32));
+
+    if( p->pUp ){
+      int nUp = 0;
+      SessionUpdate **pp = &p->pUp;
+      while( 1 ){
+        nUp++;
+        if( 0==memcmp(p->aUpdateMask, (*pp)->aMask, nU32*sizeof(u32)) ){
+          pUp = *pp;
+          *pp = pUp->pNext;
+          pUp->pNext = p->pUp;
+          p->pUp = pUp;
+          break;
+        }
+
+        if( (*pp)->pNext ){
+          pp = &(*pp)->pNext;
+        }else{
+          if( nUp>=SESSION_UPDATE_CACHE_SZ ){
+            sqlite3_finalize((*pp)->pStmt);
+            sqlite3_free(*pp);
+            *pp = 0;
+          }
+          break;
+        }
+      }
+    }
+
+    if( pUp==0 ){
+      int nByte = sizeof(SessionUpdate) * nU32*sizeof(u32);
+      int bStat1 = (sqlite3_stricmp(pIter->zTab, "sqlite_stat1")==0);
+      pUp = (SessionUpdate*)sqlite3_malloc(nByte);
+      if( pUp==0 ){
+        rc = SQLITE_NOMEM;
+      }else{
+        const char *zSep = "";
+        SessionBuffer buf;
+
+        memset(&buf, 0, sizeof(buf));
+        pUp->aMask = (u32*)&pUp[1];
+        memcpy(pUp->aMask, p->aUpdateMask, nU32*sizeof(u32));
+
+        sessionAppendStr(&buf, "UPDATE main.", &rc);
+        sessionAppendIdent(&buf, pIter->zTab, &rc);
+        sessionAppendStr(&buf, " SET ", &rc);
+
+        /* Create the assignments part of the UPDATE */
+        for(ii=0; ii<pIter->nCol; ii++){
+          if( p->abPK[ii]==0 && sessionChangesetNew(pIter, ii) ){
+            sessionAppendStr(&buf, zSep, &rc);
+            sessionAppendIdent(&buf, p->azCol[ii], &rc);
+            sessionAppendStr(&buf, " = ?", &rc);
+            sessionAppendInteger(&buf, ii*2+1, &rc);
+            zSep = ", ";
+          }
+        }
+
+        /* Create the WHERE clause part of the UPDATE */
+        zSep = "";
+        sessionAppendStr(&buf, " WHERE ", &rc);
+        for(ii=0; ii<pIter->nCol; ii++){
+          if( p->abPK[ii] || (bPatchset==0 && sessionChangesetOld(pIter, ii)) ){
+            sessionAppendStr(&buf, zSep, &rc);
+            if( bStat1 && ii==1 ){
+              assert( sqlite3_stricmp(p->azCol[ii], "idx")==0 );
+              sessionAppendStr(&buf, 
+                  "idx IS CASE "
+                  "WHEN length(?4)=0 AND typeof(?4)='blob' THEN NULL "
+                  "ELSE ?4 END ", &rc
+              );
+            }else{
+              sessionAppendIdent(&buf, p->azCol[ii], &rc);
+              sessionAppendStr(&buf, " IS ?", &rc);
+              sessionAppendInteger(&buf, ii*2+2, &rc);
+            }
+            zSep = " AND ";
+          }
+        }
+
+        if( rc==SQLITE_OK ){
+          char *zSql = (char*)buf.aBuf;
+          rc = sqlite3_prepare_v2(p->db, zSql, buf.nBuf, &pUp->pStmt, 0);
+        }
+
+        if( rc!=SQLITE_OK ){
+          sqlite3_free(pUp);
+          pUp = 0;
+        }else{
+          pUp->pNext = p->pUp;
+          p->pUp = pUp;
+        }
+        sqlite3_free(buf.aBuf);
+      }
+    }
+  }
+
+  assert( (rc==SQLITE_OK)==(pUp!=0) );
+  if( pUp ){
+    *ppStmt = pUp->pStmt;
+  }else{
+    *ppStmt = 0;
+  }
+  return rc;
+}
+
+/*
+** Free all cached UPDATE statements.
+*/
+static void sessionUpdateFree(SessionApplyCtx *p){
+  SessionUpdate *pUp;
+  SessionUpdate *pNext;
+  for(pUp=p->pUp; pUp; pUp=pNext){
+    pNext = pUp->pNext;
+    sqlite3_finalize(pUp->pStmt);
+    sqlite3_free(pUp);
+  }
+  p->pUp = 0;
+  sqlite3_free(p->aUpdateMask);
+  p->aUpdateMask = 0;
+}
+
 /*
 ** Formulate a statement to DELETE a row from database db. Assuming a table
 ** structure like this:
@@ -3554,103 +3802,6 @@ static int sessionDeleteRow(
  return rc;
 }

-/*
-** Formulate and prepare a statement to UPDATE a row from database db. 
-** Assuming a table structure like this:
-**
-**     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
-**
-** The UPDATE statement looks like this:
-**
-**     UPDATE x SET
-**     a = CASE WHEN ?2  THEN ?3  ELSE a END,
-**     b = CASE WHEN ?5  THEN ?6  ELSE b END,
-**     c = CASE WHEN ?8  THEN ?9  ELSE c END,
-**     d = CASE WHEN ?11 THEN ?12 ELSE d END
-**     WHERE a = ?1 AND c = ?7 AND (?13 OR 
-**       (?5==0 OR b IS ?4) AND (?11==0 OR d IS ?10) AND
-**     )
-**
-** For each column in the table, there are three variables to bind:
-**
-**     ?(i*3+1)    The old.* value of the column, if any.
-**     ?(i*3+2)    A boolean flag indicating that the value is being modified.
-**     ?(i*3+3)    The new.* value of the column, if any.
-**
-** Also, a boolean flag that, if set to true, causes the statement to update
-** a row even if the non-PK values do not match. This is required if the
-** conflict-handler is invoked with CHANGESET_DATA and returns
-** CHANGESET_REPLACE. This is variable "?(nCol*3+1)".
-**
-** If successful, SQLITE_OK is returned and SessionApplyCtx.pUpdate is left
-** pointing to the prepared version of the SQL statement.
-*/
-static int sessionUpdateRow(
-  sqlite3 *db,                    /* Database handle */
-  const char *zTab,               /* Table name */
-  SessionApplyCtx *p              /* Session changeset-apply context */
-){
-  int rc = SQLITE_OK;
-  int i;
-  const char *zSep = "";
-  SessionBuffer buf = {0, 0, 0};
-
-  /* Append "UPDATE tbl SET " */
-  sessionAppendStr(&buf, "UPDATE main.", &rc);
-  sessionAppendIdent(&buf, zTab, &rc);
-  sessionAppendStr(&buf, " SET ", &rc);
-
-  /* Append the assignments */
-  for(i=0; i<p->nCol; i++){
-    sessionAppendStr(&buf, zSep, &rc);
-    sessionAppendIdent(&buf, p->azCol[i], &rc);
-    sessionAppendStr(&buf, " = CASE WHEN ?", &rc);
-    sessionAppendInteger(&buf, i*3+2, &rc);
-    sessionAppendStr(&buf, " THEN ?", &rc);
-    sessionAppendInteger(&buf, i*3+3, &rc);
-    sessionAppendStr(&buf, " ELSE ", &rc);
-    sessionAppendIdent(&buf, p->azCol[i], &rc);
-    sessionAppendStr(&buf, " END", &rc);
-    zSep = ", ";
-  }
-
-  /* Append the PK part of the WHERE clause */
-  sessionAppendStr(&buf, " WHERE ", &rc);
-  for(i=0; i<p->nCol; i++){
-    if( p->abPK[i] ){
-      sessionAppendIdent(&buf, p->azCol[i], &rc);
-      sessionAppendStr(&buf, " = ?", &rc);
-      sessionAppendInteger(&buf, i*3+1, &rc);
-      sessionAppendStr(&buf, " AND ", &rc);
-    }
-  }
-
-  /* Append the non-PK part of the WHERE clause */
-  sessionAppendStr(&buf, " (?", &rc);
-  sessionAppendInteger(&buf, p->nCol*3+1, &rc);
-  sessionAppendStr(&buf, " OR 1", &rc);
-  for(i=0; i<p->nCol; i++){
-    if( !p->abPK[i] ){
-      sessionAppendStr(&buf, " AND (?", &rc);
-      sessionAppendInteger(&buf, i*3+2, &rc);
-      sessionAppendStr(&buf, "=0 OR ", &rc);
-      sessionAppendIdent(&buf, p->azCol[i], &rc);
-      sessionAppendStr(&buf, " IS ?", &rc);
-      sessionAppendInteger(&buf, i*3+1, &rc);
-      sessionAppendStr(&buf, ")", &rc);
-    }
-  }
-  sessionAppendStr(&buf, ")", &rc);
-
-  if( rc==SQLITE_OK ){
-    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pUpdate, 0);
-  }
-  sqlite3_free(buf.aBuf);
-
-  return rc;
-}
-
-
 /*
 ** Formulate and prepare an SQL statement to query table zTab by primary
 ** key. Assuming the following table structure:
@@ -3731,17 +3882,6 @@ static int sessionStat1Sql(sqlite3 *db, SessionApplyCtx *p){
        "?3)"
    );
  }
-  if( rc==SQLITE_OK ){
-    rc = sessionPrepare(db, &p->pUpdate,
-        "UPDATE main.sqlite_stat1 SET "
-        "tbl = CASE WHEN ?2 THEN ?3 ELSE tbl END, "
-        "idx = CASE WHEN ?5 THEN ?6 ELSE idx END, "
-        "stat = CASE WHEN ?8 THEN ?9 ELSE stat END  "
-        "WHERE tbl=?1 AND idx IS "
-        "CASE WHEN length(?4)=0 AND typeof(?4)='blob' THEN NULL ELSE ?4 END "
-        "AND (?10 OR ?8=0 OR stat IS ?7)"
-    );
-  }
  if( rc==SQLITE_OK ){
    rc = sessionPrepare(db, &p->pDelete,
        "DELETE FROM main.sqlite_stat1 WHERE tbl=?1 AND idx IS "
@@ -4058,7 +4198,7 @@ static int sessionApplyOneOp(
  int nCol;
  int rc = SQLITE_OK;

-  assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect );
+  assert( p->pDelete && p->pInsert && p->pSelect );
  assert( p->azCol && p->abPK );
  assert( !pbReplace || *pbReplace==0 );

@@ -4098,29 +4238,28 @@ static int sessionApplyOneOp(

  }else if( op==SQLITE_UPDATE ){
    int i;
+    sqlite3_stmt *pUp = 0;
+    int bPatchset = (pbRetry==0 || pIter->bPatchset);
+
+    rc = sessionUpdateFind(pIter, p, bPatchset, &pUp);

    /* Bind values to the UPDATE statement. */
    for(i=0; rc==SQLITE_OK && i<nCol; i++){
      sqlite3_value *pOld = sessionChangesetOld(pIter, i);
      sqlite3_value *pNew = sessionChangesetNew(pIter, i);
-
-      sqlite3_bind_int(p->pUpdate, i*3+2, !!pNew);
-      if( pOld ){
-        rc = sessionBindValue(p->pUpdate, i*3+1, pOld);
+      if( p->abPK[i] || (bPatchset==0 && pOld) ){
+        rc = sessionBindValue(pUp, i*2+2, pOld);
      }
      if( rc==SQLITE_OK && pNew ){
-        rc = sessionBindValue(p->pUpdate, i*3+3, pNew);
+        rc = sessionBindValue(pUp, i*2+1, pNew);
      }
    }
-    if( rc==SQLITE_OK ){
-      sqlite3_bind_int(p->pUpdate, nCol*3+1, pbRetry==0 || pIter->bPatchset);
-    }
    if( rc!=SQLITE_OK ) return rc;

    /* Attempt the UPDATE. In the case of a NOTFOUND or DATA conflict,
    ** the result will be SQLITE_OK with 0 rows modified. */
-    sqlite3_step(p->pUpdate);
-    rc = sqlite3_reset(p->pUpdate);
+    sqlite3_step(pUp);
+    rc = sqlite3_reset(pUp);

    if( rc==SQLITE_OK && sqlite3_changes(p->db)==0 ){
      /* A NOTFOUND or DATA error. Search the table to see if it contains
@@ -4251,7 +4390,9 @@ static int sessionRetryConstraints(
    SessionBuffer cons = pApply->constraints;
    memset(&pApply->constraints, 0, sizeof(SessionBuffer));

-    rc = sessionChangesetStart(&pIter2, 0, 0, cons.nBuf, cons.aBuf, 0);
+    rc = sessionChangesetStart(
+        &pIter2, 0, 0, cons.nBuf, cons.aBuf, pApply->bInvertConstraints, 1
+    );
    if( rc==SQLITE_OK ){
      size_t nByte = 2*pApply->nCol*sizeof(sqlite3_value*);
      int rc2;
@@ -4318,6 +4459,7 @@ static int sessionChangesetApply(
  pIter->in.bNoDiscard = 1;
  memset(&sApply, 0, sizeof(sApply));
  sApply.bRebase = (ppRebase && pnRebase);
+  sApply.bInvertConstraints = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);
  sqlite3_mutex_enter(sqlite3_db_mutex(db));
  if( (flags & SQLITE_CHANGESETAPPLY_NOSAVEPOINT)==0 ){
    rc = sqlite3_exec(db, "SAVEPOINT changeset_apply", 0, 0, 0);
@@ -4340,14 +4482,13 @@ static int sessionChangesetApply(
      );
      if( rc!=SQLITE_OK ) break;

+      sessionUpdateFree(&sApply);
      sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */
      sqlite3_finalize(sApply.pDelete);
-      sqlite3_finalize(sApply.pUpdate); 
      sqlite3_finalize(sApply.pInsert);
      sqlite3_finalize(sApply.pSelect);
      sApply.db = db;
      sApply.pDelete = 0;
-      sApply.pUpdate = 0;
      sApply.pInsert = 0;
      sApply.pSelect = 0;
      sApply.nCol = 0;
@@ -4375,7 +4516,7 @@ static int sessionChangesetApply(
        int i;

        sqlite3changeset_pk(pIter, &abPK, 0);
-        rc = sessionTableInfo(
+        rc = sessionTableInfo(0, 
            db, "main", zNew, &sApply.nCol, &zTab, &sApply.azCol, &sApply.abPK
        );
        if( rc!=SQLITE_OK ) break;
@@ -4411,11 +4552,10 @@ static int sessionChangesetApply(
            }
            sApply.bStat1 = 1;
          }else{
-            if((rc = sessionSelectRow(db, zTab, &sApply))
-                || (rc = sessionUpdateRow(db, zTab, &sApply))
-                || (rc = sessionDeleteRow(db, zTab, &sApply))
-                || (rc = sessionInsertRow(db, zTab, &sApply))
-              ){
+            if( (rc = sessionSelectRow(db, zTab, &sApply))
+             || (rc = sessionDeleteRow(db, zTab, &sApply))
+             || (rc = sessionInsertRow(db, zTab, &sApply))
+            ){
              break;
            }
            sApply.bStat1 = 0;
@@ -4474,9 +4614,9 @@ static int sessionChangesetApply(
    *pnRebase = sApply.rebase.nBuf;
    sApply.rebase.aBuf = 0;
  }
+  sessionUpdateFree(&sApply);
  sqlite3_finalize(sApply.pInsert);
  sqlite3_finalize(sApply.pDelete);
-  sqlite3_finalize(sApply.pUpdate);
  sqlite3_finalize(sApply.pSelect);
  sqlite3_free((char*)sApply.azCol);  /* cast works around VC++ bug */
  sqlite3_free((char*)sApply.constraints.aBuf);
@@ -4507,8 +4647,8 @@ int sqlite3changeset_apply_v2(
  int flags
 ){
  sqlite3_changeset_iter *pIter;  /* Iterator to skip through changeset */  
-  int bInverse = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);
-  int rc = sessionChangesetStart(&pIter, 0, 0, nChangeset, pChangeset,bInverse);
+  int bInv = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);
+  int rc = sessionChangesetStart(&pIter, 0, 0, nChangeset, pChangeset, bInv, 1);
  if( rc==SQLITE_OK ){
    rc = sessionChangesetApply(
        db, pIter, xFilter, xConflict, pCtx, ppRebase, pnRebase, flags
@@ -4566,7 +4706,7 @@ int sqlite3changeset_apply_v2_strm(
 ){
  sqlite3_changeset_iter *pIter;  /* Iterator to skip through changeset */  
  int bInverse = !!(flags & SQLITE_CHANGESETAPPLY_INVERT);
-  int rc = sessionChangesetStart(&pIter, xInput, pIn, 0, 0, bInverse);
+  int rc = sessionChangesetStart(&pIter, xInput, pIn, 0, 0, bInverse, 1);
  if( rc==SQLITE_OK ){
    rc = sessionChangesetApply(
        db, pIter, xFilter, xConflict, pCtx, ppRebase, pnRebase, flags
@@ -4854,7 +4994,7 @@ static int sessionChangesetToHash(
      }
    }

-    if( sessionGrowHash(pIter->bPatchset, pTab) ){
+    if( sessionGrowHash(0, pIter->bPatchset, pTab) ){
      rc = SQLITE_NOMEM;
      break;
    }
@@ -5040,7 +5180,7 @@ int sqlite3changegroup_output_strm(
 */
 void sqlite3changegroup_delete(sqlite3_changegroup *pGrp){
  if( pGrp ){
-    sessionDeleteTable(pGrp->pList);
+    sessionDeleteTable(0, pGrp->pList);
    sqlite3_free(pGrp);
  }
 }
@@ -5186,7 +5326,7 @@ static void sessionAppendPartialUpdate(
      int n1 = sessionSerialLen(a1);
      int n2 = sessionSerialLen(a2);
      if( pIter->abPK[i] || a2[0]==0 ){
-        if( !pIter->abPK[i] ) bData = 1;
+        if( !pIter->abPK[i] && a1[0] ) bData = 1;
        memcpy(pOut, a1, n1);
        pOut += n1;
      }else if( a2[0]!=0xFF ){
@@ -5441,7 +5581,7 @@ int sqlite3rebaser_rebase_strm(
 */
 void sqlite3rebaser_delete(sqlite3_rebaser *p){
  if( p ){
-    sessionDeleteTable(p->grp.pList);
+    sessionDeleteTable(0, p->grp.pList);
    sqlite3_free(p);
  }
 }
@@ -440,6 +440,14 @@ int sqlite3session_patchset(
 */
 int sqlite3session_isempty(sqlite3_session *pSession);

+/*
+** CAPI3REF: Query for the amount of heap memory used by a session object.
+**
+** This API returns the total amount of heap memory in bytes currently 
+** used by the session object passed as the only argument.
+*/
+sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
+
 /*
 ** CAPI3REF: Create An Iterator To Traverse A Changeset 
 ** CONSTRUCTOR: sqlite3_changeset_iter
@@ -542,18 +550,23 @@ int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
 ** is not the case, this function returns [SQLITE_MISUSE].
 **
-** If argument pzTab is not NULL, then *pzTab is set to point to a
-** nul-terminated utf-8 encoded string containing the name of the table
-** affected by the current change. The buffer remains valid until either
-** sqlite3changeset_next() is called on the iterator or until the 
-** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 
-** set to the number of columns in the table affected by the change. If
-** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
+** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
+** outputs are set through these pointers: 
+**
+** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
+** depending on the type of change that the iterator currently points to;
+**
+** *pnCol is set to the number of columns in the table affected by the change; and
+**
+** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
+** the name of the table affected by the current change. The buffer remains
+** valid until either sqlite3changeset_next() is called on the iterator
+** or until the conflict-handler function returns.
+**
+** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
 ** is an indirect change, or false (0) otherwise. See the documentation for
 ** [sqlite3session_indirect()] for a description of direct and indirect
-** changes. Finally, if pOp is not NULL, then *pOp is set to one of 
-** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 
-** type of change that the iterator currently points to.
+** changes.
 **
 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
 ** SQLite error code is returned. The values of the output variables may not
@@ -146,7 +146,10 @@ static int SQLITE_TCLAPI test_sql_exec_changeset(
 static int test_tcl_integer(Tcl_Interp *interp, const char *zVar){
  Tcl_Obj *pObj;
  int iVal = 0;
-  pObj = Tcl_ObjGetVar2(interp, Tcl_NewStringObj(zVar, -1), 0, TCL_GLOBAL_ONLY);
+  Tcl_Obj *pName = Tcl_NewStringObj(zVar, -1);
+  Tcl_IncrRefCount(pName);
+  pObj = Tcl_ObjGetVar2(interp, pName, 0, TCL_GLOBAL_ONLY);
+  Tcl_DecrRefCount(pName);
  if( pObj ) Tcl_GetIntFromObj(0, pObj, &iVal);
  return iVal;
 }
@@ -227,7 +230,7 @@ static int SQLITE_TCLAPI test_session_cmd(
 ){
  TestSession *p = (TestSession*)clientData;
  sqlite3_session *pSession = p->pSession;
-  struct SessionSubcmd {
+  static struct SessionSubcmd {
    const char *zSub;
    int nArg;
    const char *zMsg;
@@ -242,6 +245,7 @@ static int SQLITE_TCLAPI test_session_cmd(
    { "table_filter", 1, "SCRIPT",     }, /* 6 */
    { "patchset",     0, "",           }, /* 7 */
    { "diff",         2, "FROMDB TBL", }, /* 8 */
+    { "memory_used",  0, "",           }, /* 9 */
    { 0 }
  };
  int iSub;
@@ -347,6 +351,12 @@ static int SQLITE_TCLAPI test_session_cmd(
      }
      break;
    }
+
+    case 9: {      /* memory_used */
+      sqlite3_int64 nMalloc = sqlite3session_memory_used(pSession);
+      Tcl_SetObjResult(interp, Tcl_NewWideIntObj(nMalloc));
+      break;
+    }
  }

  return TCL_OK;
@@ -1131,7 +1141,7 @@ static int SQLITE_TCLAPI test_rebaser_cmd(
  int objc,
  Tcl_Obj *CONST objv[]
 ){
-  struct RebaseSubcmd {
+  static struct RebaseSubcmd {
    const char *zSub;
    int nArg;
    const char *zMsg;
@@ -1248,7 +1258,7 @@ static int SQLITE_TCLAPI test_sqlite3session_config(
  int objc,
  Tcl_Obj *CONST objv[]
 ){
-  struct ConfigOpt {
+  static struct ConfigOpt {
    const char *zSub;
    int op;
  } aSub[] = {
@@ -360,9 +360,12 @@ TESTSRC = \
 #
 TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
+  $(TOP)/ext/misc/appendvfs.c \
  $(TOP)/ext/misc/carray.c \
+  $(TOP)/ext/misc/cksumvfs.c \
  $(TOP)/ext/misc/closure.c \
  $(TOP)/ext/misc/csv.c \
+  $(TOP)/ext/misc/decimal.c \
  $(TOP)/ext/misc/eval.c \
  $(TOP)/ext/misc/explain.c \
  $(TOP)/ext/misc/fileio.c \
@@ -548,13 +551,13 @@ ST_OPT = -DSQLITE_THREADSAFE=0
 # This is the default Makefile target.  The objects listed here
 # are what get build when you type just "make" with no arguments.
 #
-all:	sqlite3.h libsqlite3.a sqlite3$(EXE)
+all:	sqlite3.h sqlite3ext.h libsqlite3.a sqlite3$(EXE)

-libsqlite3.a:	$(LIBOBJ)
+libsqlite3.a: sqlite3.h	$(LIBOBJ)
 	$(AR) libsqlite3.a $(LIBOBJ)
 	$(RANLIB) libsqlite3.a

-sqlite3$(EXE):	shell.c libsqlite3.a sqlite3.h
+sqlite3$(EXE):	sqlite3.h libsqlite3.a shell.c
 	$(TCCX) $(READLINE_FLAGS) -o sqlite3$(EXE) $(SHELL_OPT) \
 		shell.c libsqlite3.a $(LIBREADLINE) $(TLIBS) $(THREADLIB)

@@ -727,6 +730,12 @@ parse.c:	$(TOP)/src/parse.y lemon
 sqlite3.h:	$(TOP)/src/sqlite.h.in $(TOP)/manifest mksourceid $(TOP)/VERSION $(TOP)/ext/rtree/sqlite3rtree.h
 	tclsh $(TOP)/tool/mksqlite3h.tcl $(TOP) >sqlite3.h

+sqlite3rc.h:	$(TOP)/src/sqlite3.rc $(TOP)/VERSION
+	echo '#ifndef SQLITE_RESOURCE_VERSION' >$@
+	echo -n '#define SQLITE_RESOURCE_VERSION ' >>$@
+	cat $(TOP)/VERSION | tclsh $(TOP)/tool/replace.tcl exact . , >>$@
+	echo '#endif' >>sqlite3rc.h
+
 keywordhash.h:	$(TOP)/tool/mkkeywordhash.c
 	$(BCC) -o mkkeywordhash $(OPTS) $(TOP)/tool/mkkeywordhash.c
 	./mkkeywordhash >keywordhash.h
@@ -735,9 +744,11 @@ keywordhash.h:	$(TOP)/tool/mkkeywordhash.c
 SHELL_SRC = \
 	$(TOP)/src/shell.c.in \
        $(TOP)/ext/misc/appendvfs.c \
-	$(TOP)/ext/misc/shathree.c \
-	$(TOP)/ext/misc/fileio.c \
 	$(TOP)/ext/misc/completion.c \
+        $(TOP)/ext/misc/decimal.c \
+	$(TOP)/ext/misc/fileio.c \
+        $(TOP)/ext/misc/ieee754.c \
+	$(TOP)/ext/misc/shathree.c \
 	$(TOP)/ext/misc/sqlar.c \
        $(TOP)/ext/misc/uint.c \
 	$(TOP)/ext/expert/sqlite3expert.c \
@@ -814,13 +825,13 @@ fts3_unicode2.o:	$(TOP)/ext/fts3/fts3_unicode2.c $(HDR) $(EXTHDR)
 fts3_write.o:	$(TOP)/ext/fts3/fts3_write.c $(HDR) $(EXTHDR)
 	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/fts3/fts3_write.c

-fts5.o:	fts5.c
+fts5.o:	fts5.c  sqlite3ext.h sqlite3.h
 	$(TCCX) -DSQLITE_CORE -c fts5.c

-json1.o:	$(TOP)/ext/misc/json1.c
+json1.o:	$(TOP)/ext/misc/json1.c sqlite3ext.h sqlite3.h
 	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/misc/json1.c

-stmt.o:	$(TOP)/ext/misc/stmt.c
+stmt.o:	$(TOP)/ext/misc/stmt.c sqlite3ext.h sqlite3.h
 	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/misc/stmt.c

 rtree.o:	$(TOP)/ext/rtree/rtree.c $(HDR) $(EXTHDR)
@@ -903,6 +914,7 @@ TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_STMTVTAB
 TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_DBPAGE_VTAB
 TESTFIXTURE_FLAGS += -DSQLITE_ENABLE_BYTECODE_VTAB
 TESTFIXTURE_FLAGS += -DTCLSH_INIT_PROC=sqlite3TestInit
+TESTFIXTURE_FLAGS += -DSQLITE_CKSUMVFS_STATIC

 testfixture$(EXE): $(TESTSRC2) libsqlite3.a $(TESTSRC) $(TOP)/src/tclsqlite.c
 	$(TCCX) $(TCL_FLAGS) $(TESTFIXTURE_FLAGS)                            \
@@ -943,7 +955,7 @@ fuzztest:	fuzzcheck$(EXE) $(FUZZDATA) sessionfuzz$(EXE) $(TOP)/test/sessionfuzz-
 	./sessionfuzz run $(TOP)/test/sessionfuzz-data1.db

 valgrindfuzz:	fuzzcheck$(EXE) $(FUZZDATA) sessionfuzz$(EXE) $(TOP)/test/sessionfuzz-data1.db
-	valgrind ./fuzzcheck$(EXE) --cell-size-check --limit-mem 10M --timeout 600 $(FUZZDATA)
+	valgrind ./fuzzcheck$(EXE) --cell-size-check --limit-mem 10M $(FUZZDATA)
 	valgrind ./sessionfuzz run $(TOP)/test/sessionfuzz-data1.db

 # The veryquick.test TCL tests.
@@ -975,6 +987,9 @@ valgrindtest:	$(TESTPROGS) valgrindfuzz
 smoketest:	$(TESTPROGS) fuzzcheck$(EXE)
 	./testfixture$(EXE) $(TOP)/test/main.test $(TESTOPTS)

+shelltest: $(TESTPROGS)
+	./testfixture$(EXT) $(TOP)/test/permutations.test shell
+
 # The next two rules are used to support the "threadtest" target. Building
 # threadtest runs a few thread-safety tests that are implemented in C. This
 # target is invoked by the releasetest.tcl script.
@@ -1076,10 +1091,10 @@ checksymbols: sqlite3.o
 # a tarball named for the version number.  Ex:  sqlite-autoconf-3110000.tar.gz.
 # The snapshot-tarball target builds a tarball named by the SHA1 hash
 #
-amalgamation-tarball: sqlite3.c
+amalgamation-tarball: sqlite3.c sqlite3rc.h
 	TOP=$(TOP) sh $(TOP)/tool/mkautoconfamal.sh --normal

-snapshot-tarball: sqlite3.c
+snapshot-tarball: sqlite3.c sqlite3rc.h
 	TOP=$(TOP) sh $(TOP)/tool/mkautoconfamal.sh --snapshot


@@ -1 +1 @@
-49e4dc72f7a4b28e4b49d7b91030bc986aea3ff44dac38cb6e68305800cd1de5
+5d4c65779dab868b285519b19e4cf9d451d50c6048f06f653aa701ec212df45e
@@ -49,25 +49,32 @@ static int isAlterableTable(Parse *pParse, Table *pTab){
 ** statement to ensure that the operation has not rendered any schema
 ** objects unusable.
 */
-static void renameTestSchema(Parse *pParse, const char *zDb, int bTemp){
+static void renameTestSchema(
+  Parse *pParse,                  /* Parse context */
+  const char *zDb,                /* Name of db to verify schema of */
+  int bTemp,                      /* True if this is the temp db */
+  const char *zWhen,              /* "when" part of error message */
+  const char *zDropColumn         /* Name of column being dropped */
+){
+  pParse->colNamesSet = 1;
  sqlite3NestedParse(pParse, 
      "SELECT 1 "
-      "FROM \"%w\".%s "
+      "FROM \"%w\"." DFLT_SCHEMA_TABLE " "
      "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"
      " AND sql NOT LIKE 'create virtual%%'"
-      " AND sqlite_rename_test(%Q, sql, type, name, %d)=NULL ",
-      zDb, MASTER_NAME, 
-      zDb, bTemp
+      " AND sqlite_rename_test(%Q, sql, type, name, %d, %Q, %Q)=NULL ",
+      zDb,
+      zDb, bTemp, zWhen, zDropColumn
  );

  if( bTemp==0 ){
    sqlite3NestedParse(pParse, 
        "SELECT 1 "
-        "FROM temp.%s "
+        "FROM temp." DFLT_SCHEMA_TABLE " "
        "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"
        " AND sql NOT LIKE 'create virtual%%'"
-        " AND sqlite_rename_test(%Q, sql, type, name, 1)=NULL ",
-        MASTER_NAME, zDb 
+        " AND sqlite_rename_test(%Q, sql, type, name, 1, %Q, %Q)=NULL ",
+        zDb, zWhen, zDropColumn
    );
  }
 }
@@ -76,12 +83,12 @@ static void renameTestSchema(Parse *pParse, const char *zDb, int bTemp){
 ** Generate code to reload the schema for database iDb. And, if iDb!=1, for
 ** the temp database as well.
 */
-static void renameReloadSchema(Parse *pParse, int iDb){
+static void renameReloadSchema(Parse *pParse, int iDb, u16 p5){
  Vdbe *v = pParse->pVdbe;
  if( v ){
    sqlite3ChangeCookie(pParse, iDb);
-    sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, iDb, 0);
-    if( iDb!=1 ) sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, 1, 0);
+    sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, iDb, 0, p5);
+    if( iDb!=1 ) sqlite3VdbeAddParseSchemaOp(pParse->pVdbe, 1, 0, p5);
  }
 }

@@ -123,7 +130,10 @@ void sqlite3AlterRenameTable(
  /* Check that a table or index named 'zName' does not already exist
  ** in database iDb. If so, this is an error.
  */
-  if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
+  if( sqlite3FindTable(db, zName, zDb)
+   || sqlite3FindIndex(db, zName, zDb)
+   || sqlite3IsShadowTableOf(db, pTab, zName)
+  ){
    sqlite3ErrorMsg(pParse, 
        "there is already another table or index with this name: %s", zName);
    goto exit_rename_table;
@@ -182,17 +192,17 @@ void sqlite3AlterRenameTable(
  /* Rewrite all CREATE TABLE, INDEX, TRIGGER or VIEW statements in
  ** the schema to use the new table name.  */
  sqlite3NestedParse(pParse, 
-      "UPDATE \"%w\".%s SET "
+      "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
      "sql = sqlite_rename_table(%Q, type, name, sql, %Q, %Q, %d) "
      "WHERE (type!='index' OR tbl_name=%Q COLLATE nocase)"
      "AND   name NOT LIKE 'sqliteX_%%' ESCAPE 'X'"
-      , zDb, MASTER_NAME, zDb, zTabName, zName, (iDb==1), zTabName
+      , zDb, zDb, zTabName, zName, (iDb==1), zTabName
  );

-  /* Update the tbl_name and name columns of the sqlite_master table
+  /* Update the tbl_name and name columns of the sqlite_schema table
  ** as required.  */
  sqlite3NestedParse(pParse,
-      "UPDATE %Q.%s SET "
+      "UPDATE %Q." DFLT_SCHEMA_TABLE " SET "
          "tbl_name = %Q, "
          "name = CASE "
            "WHEN type='table' THEN %Q "
@@ -202,7 +212,7 @@ void sqlite3AlterRenameTable(
            "ELSE name END "
      "WHERE tbl_name=%Q COLLATE nocase AND "
          "(type='table' OR type='index' OR type='trigger');", 
-      zDb, MASTER_NAME, 
+      zDb,
      zName, zName, zName, 
      nTabName, zTabName
  );
@@ -223,11 +233,11 @@ void sqlite3AlterRenameTable(
  ** as required.  */
  if( iDb!=1 ){
    sqlite3NestedParse(pParse, 
-        "UPDATE sqlite_temp_master SET "
+        "UPDATE sqlite_temp_schema SET "
            "sql = sqlite_rename_table(%Q, type, name, sql, %Q, %Q, 1), "
            "tbl_name = "
              "CASE WHEN tbl_name=%Q COLLATE nocase AND "
-              "          sqlite_rename_test(%Q, sql, type, name, 1) "
+              "  sqlite_rename_test(%Q, sql, type, name, 1, 'after rename',0) "
              "THEN %Q ELSE tbl_name END "
            "WHERE type IN ('view', 'trigger')"
        , zDb, zTabName, zName, zTabName, zDb, zName);
@@ -246,8 +256,8 @@ void sqlite3AlterRenameTable(
  }
 #endif

-  renameReloadSchema(pParse, iDb);
-  renameTestSchema(pParse, zDb, iDb==1);
+  renameReloadSchema(pParse, iDb, INITFLAG_AlterRename);
+  renameTestSchema(pParse, zDb, iDb==1, "after rename", 0);

 exit_rename_table:
  sqlite3SrcListDelete(db, pSrc);
@@ -255,6 +265,22 @@ exit_rename_table:
  db->mDbFlags = savedDbFlags;
 }

+/*
+** Write code that will raise an error if the table described by
+** zDb and zTab is not empty.
+*/
+static void sqlite3ErrorIfNotEmpty(
+  Parse *pParse,        /* Parsing context */
+  const char *zDb,      /* Schema holding the table */
+  const char *zTab,     /* Table to check for empty */
+  const char *zErr      /* Error message text */
+){
+  sqlite3NestedParse(pParse,
+     "SELECT raise(ABORT,%Q) FROM \"%w\".\"%w\"",
+     zErr, zDb, zTab
+  );
+}
+
 /*
 ** This function is called after an "ALTER TABLE ... ADD" statement
 ** has been parsed. Argument pColDef contains the text of the new
@@ -307,7 +333,8 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
    return;
  }
  if( pNew->pIndex ){
-    sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
+    sqlite3ErrorMsg(pParse,
+         "Cannot add a UNIQUE column");
    return;
  }
  if( (pCol->colFlags & COLFLAG_GENERATED)==0 ){
@@ -320,16 +347,15 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
      pDflt = 0;
    }
    if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){
-      sqlite3ErrorMsg(pParse, 
+      sqlite3ErrorIfNotEmpty(pParse, zDb, zTab,
          "Cannot add a REFERENCES column with non-NULL default value");
-      return;
    }
    if( pCol->notNull && !pDflt ){
-      sqlite3ErrorMsg(pParse, 
+      sqlite3ErrorIfNotEmpty(pParse, zDb, zTab,
          "Cannot add a NOT NULL column with default value NULL");
-      return;
    }

+
    /* Ensure the default expression is something that sqlite3ValueFromExpr()
    ** can handle (i.e. not CURRENT_TIME etc.)
    */
@@ -343,14 +369,13 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
        return;
      }
      if( !pVal ){
-        sqlite3ErrorMsg(pParse,"Cannot add a column with non-constant default");
-        return;
+        sqlite3ErrorIfNotEmpty(pParse, zDb, zTab,
+           "Cannot add a column with non-constant default");
      }
      sqlite3ValueFree(pVal);
    }
  }else if( pCol->colFlags & COLFLAG_STORED ){
-    sqlite3ErrorMsg(pParse, "cannot add a STORED column");
-    return;
+    sqlite3ErrorIfNotEmpty(pParse, zDb, zTab, "cannot add a STORED column");
  }


@@ -363,11 +388,14 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
      *zEnd-- = '\0';
    }
    db->mDbFlags |= DBFLAG_PreferBuiltin;
+    /* substr() operations on characters, but addColOffset is in bytes. So we
+    ** have to use printf() to translate between these units: */
    sqlite3NestedParse(pParse, 
-        "UPDATE \"%w\".%s SET "
-          "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
+        "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
+          "sql = printf('%%.%ds, ',sql) || %Q"
+          " || substr(sql,1+length(printf('%%.%ds',sql))) "
        "WHERE type = 'table' AND name = %Q", 
-      zDb, MASTER_NAME, pNew->addColOffset, zCol, pNew->addColOffset+1,
+      zDb, pNew->addColOffset, zCol, pNew->addColOffset,
      zTab
    );
    sqlite3DbFree(db, zCol);
@@ -391,7 +419,7 @@ void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
  }

  /* Reload the table definition */
-  renameReloadSchema(pParse, iDb);
+  renameReloadSchema(pParse, iDb, INITFLAG_AlterRename);
 }

 /*
@@ -491,7 +519,7 @@ exit_begin_add_column:
 ** Or, if pTab is not a view or virtual table, zero is returned.
 */
 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)
-static int isRealTable(Parse *pParse, Table *pTab){
+static int isRealTable(Parse *pParse, Table *pTab, int bDrop){
  const char *zType = 0;
 #ifndef SQLITE_OMIT_VIEW
  if( pTab->pSelect ){
@@ -504,15 +532,16 @@ static int isRealTable(Parse *pParse, Table *pTab){
  }
 #endif
  if( zType ){
-    sqlite3ErrorMsg(
-        pParse, "cannot rename columns of %s \"%s\"", zType, pTab->zName
+    sqlite3ErrorMsg(pParse, "cannot %s %s \"%s\"", 
+        (bDrop ? "drop column from" : "rename columns of"),
+        zType, pTab->zName
    );
    return 1;
  }
  return 0;
 }
 #else /* !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE) */
-# define isRealTable(x,y) (0)
+# define isRealTable(x,y,z) (0)
 #endif

 /*
@@ -541,7 +570,7 @@ void sqlite3AlterRenameColumn(

  /* Cannot alter a system table */
  if( SQLITE_OK!=isAlterableTable(pParse, pTab) ) goto exit_rename_column;
-  if( SQLITE_OK!=isRealTable(pParse, pTab) ) goto exit_rename_column;
+  if( SQLITE_OK!=isRealTable(pParse, pTab, 0) ) goto exit_rename_column;

  /* Which schema holds the table to be altered */  
  iSchema = sqlite3SchemaToIndex(db, pTab->pSchema);
@@ -569,7 +598,7 @@ void sqlite3AlterRenameColumn(

  /* Do the rename operation using a recursive UPDATE statement that
  ** uses the sqlite_rename_column() SQL function to compute the new
-  ** CREATE statement text for the sqlite_master table.
+  ** CREATE statement text for the sqlite_schema table.
  */
  sqlite3MayAbort(pParse);
  zNew = sqlite3NameFromToken(db, pNew);
@@ -577,27 +606,26 @@ void sqlite3AlterRenameColumn(
  assert( pNew->n>0 );
  bQuote = sqlite3Isquote(pNew->z[0]);
  sqlite3NestedParse(pParse, 
-      "UPDATE \"%w\".%s SET "
+      "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
      "sql = sqlite_rename_column(sql, type, name, %Q, %Q, %d, %Q, %d, %d) "
      "WHERE name NOT LIKE 'sqliteX_%%' ESCAPE 'X' "
      " AND (type != 'index' OR tbl_name = %Q)"
      " AND sql NOT LIKE 'create virtual%%'",
-      zDb, MASTER_NAME, 
+      zDb,
      zDb, pTab->zName, iCol, zNew, bQuote, iSchema==1,
      pTab->zName
  );

  sqlite3NestedParse(pParse, 
-      "UPDATE temp.%s SET "
+      "UPDATE temp." DFLT_SCHEMA_TABLE " SET "
      "sql = sqlite_rename_column(sql, type, name, %Q, %Q, %d, %Q, %d, 1) "
      "WHERE type IN ('trigger', 'view')",
-      MASTER_NAME, 
      zDb, pTab->zName, iCol, zNew, bQuote
  );

  /* Drop and reload the database schema. */
-  renameReloadSchema(pParse, iSchema);
-  renameTestSchema(pParse, zDb, iSchema==1);
+  renameReloadSchema(pParse, iSchema, INITFLAG_AlterRename);
+  renameTestSchema(pParse, zDb, iSchema==1, "after rename", 0);

 exit_rename_column:
  sqlite3SrcListDelete(db, pSrc);
@@ -849,23 +877,33 @@ static void renameTokenFree(sqlite3 *db, RenameToken *pToken){

 /*
 ** Search the Parse object passed as the first argument for a RenameToken
-** object associated with parse tree element pPtr. If found, remove it
-** from the Parse object and add it to the list maintained by the
-** RenameCtx object passed as the second argument.
+** object associated with parse tree element pPtr. If found, return a pointer
+** to it. Otherwise, return NULL.
+**
+** If the second argument passed to this function is not NULL and a matching
+** RenameToken object is found, remove it from the Parse object and add it to
+** the list maintained by the RenameCtx object.
 */
-static void renameTokenFind(Parse *pParse, struct RenameCtx *pCtx, void *pPtr){
+static RenameToken *renameTokenFind(
+  Parse *pParse, 
+  struct RenameCtx *pCtx, 
+  void *pPtr
+){
  RenameToken **pp;
  assert( pPtr!=0 );
  for(pp=&pParse->pRename; (*pp); pp=&(*pp)->pNext){
    if( (*pp)->p==pPtr ){
      RenameToken *pToken = *pp;
-      *pp = pToken->pNext;
-      pToken->pNext = pCtx->pList;
-      pCtx->pList = pToken;
-      pCtx->nList++;
-      break;
+      if( pCtx ){
+        *pp = pToken->pNext;
+        pToken->pNext = pCtx->pList;
+        pCtx->pList = pToken;
+        pCtx->nList++;
+      }
+      return pToken;
    }
  }
+  return 0;
 }

 /*
@@ -936,7 +974,7 @@ static RenameToken *renameColumnTokenNext(RenameCtx *pCtx){
 */
 static void renameColumnParseError(
  sqlite3_context *pCtx, 
-  int bPost,
+  const char *zWhen,
  sqlite3_value *pType,
  sqlite3_value *pObject,
  Parse *pParse
@@ -945,8 +983,8 @@ static void renameColumnParseError(
  const char *zN = (const char*)sqlite3_value_text(pObject);
  char *zErr;

-  zErr = sqlite3_mprintf("error in %s %s%s: %s", 
-      zT, zN, (bPost ? " after rename" : ""),
+  zErr = sqlite3_mprintf("error in %s %s%s%s: %s", 
+      zT, zN, (zWhen[0] ? " " : ""), zWhen,
      pParse->zErrMsg
  );
  sqlite3_result_error(pCtx, zErr, -1);
@@ -1011,12 +1049,17 @@ static int renameParseSql(
  const char *zDb,                /* Name of schema SQL belongs to */
  sqlite3 *db,                    /* Database handle */
  const char *zSql,               /* SQL to parse */
-  int bTemp                       /* True if SQL is from temp schema */
+  int bTemp,                      /* True if SQL is from temp schema */
+  const char *zDropColumn         /* Name of column being dropped */
 ){
  int rc;
  char *zErr = 0;

  db->init.iDb = bTemp ? 1 : sqlite3FindDbName(db, zDb);
+  if( zDropColumn ){
+    db->init.bDropColumn = 1;
+    db->init.azInit = (char**)&zDropColumn;
+  }

  /* Parse the SQL statement passed as the first argument. If no error
  ** occurs and the parse does not result in a new table, index or
@@ -1025,7 +1068,7 @@ static int renameParseSql(
  p->eParseMode = PARSE_MODE_RENAME;
  p->db = db;
  p->nQueryLoop = 1;
-  rc = sqlite3RunParser(p, zSql, &zErr);
+  rc = zSql ? sqlite3RunParser(p, zSql, &zErr) : SQLITE_NOMEM;
  assert( p->zErrMsg==0 );
  assert( rc!=SQLITE_OK || zErr==0 );
  p->zErrMsg = zErr;
@@ -1049,6 +1092,7 @@ static int renameParseSql(
 #endif

  db->init.iDb = 0;
+  db->init.bDropColumn = 0;
  return rc;
 }

@@ -1143,7 +1187,7 @@ static int renameEditSql(
 ** successful. Otherwise, return an SQLite error code and leave an error
 ** message in the Parse object.
 */
-static int renameResolveTrigger(Parse *pParse, const char *zDb){
+static int renameResolveTrigger(Parse *pParse){
  sqlite3 *db = pParse->db;
  Trigger *pNew = pParse->pNewTrigger;
  TriggerStep *pStep;
@@ -1174,27 +1218,39 @@ static int renameResolveTrigger(Parse *pParse, const char *zDb){
      if( pParse->nErr ) rc = pParse->rc;
    }
    if( rc==SQLITE_OK && pStep->zTarget ){
-      Table *pTarget = sqlite3LocateTable(pParse, 0, pStep->zTarget, zDb);
-      if( pTarget==0 ){
-        rc = SQLITE_ERROR;
-      }else if( SQLITE_OK==(rc = sqlite3ViewGetColumnNames(pParse, pTarget)) ){
-        SrcList sSrc;
-        memset(&sSrc, 0, sizeof(sSrc));
-        sSrc.nSrc = 1;
-        sSrc.a[0].zName = pStep->zTarget;
-        sSrc.a[0].pTab = pTarget;
-        sNC.pSrcList = &sSrc;
-        if( pStep->pWhere ){
+      SrcList *pSrc = sqlite3TriggerStepSrc(pParse, pStep);
+      if( pSrc ){
+        int i;
+        for(i=0; i<pSrc->nSrc && rc==SQLITE_OK; i++){
+          SrcItem *p = &pSrc->a[i];
+          p->iCursor = pParse->nTab++;
+          if( p->pSelect ){
+            sqlite3SelectPrep(pParse, p->pSelect, 0);
+            sqlite3ExpandSubquery(pParse, p);
+            assert( i>0 );
+            assert( pStep->pFrom->a[i-1].pSelect );
+            sqlite3SelectPrep(pParse, pStep->pFrom->a[i-1].pSelect, 0);
+          }else{
+            p->pTab = sqlite3LocateTableItem(pParse, 0, p);
+            if( p->pTab==0 ){
+              rc = SQLITE_ERROR;
+            }else{
+              p->pTab->nTabRef++;
+              rc = sqlite3ViewGetColumnNames(pParse, p->pTab);
+            }
+          }
+        }
+        sNC.pSrcList = pSrc;
+        if( rc==SQLITE_OK && pStep->pWhere ){
          rc = sqlite3ResolveExprNames(&sNC, pStep->pWhere);
        }
        if( rc==SQLITE_OK ){
          rc = sqlite3ResolveExprListNames(&sNC, pStep->pExprList);
        }
        assert( !pStep->pUpsert || (!pStep->pWhere && !pStep->pExprList) );
-        if( pStep->pUpsert ){
+        if( pStep->pUpsert && rc==SQLITE_OK ){
          Upsert *pUpsert = pStep->pUpsert;
-          assert( rc==SQLITE_OK );
-          pUpsert->pUpsertSrc = &sSrc;
+          pUpsert->pUpsertSrc = pSrc;
          sNC.uNC.pUpsert = pUpsert;
          sNC.ncFlags = NC_UUpsert;
          rc = sqlite3ResolveExprListNames(&sNC, pUpsert->pUpsertTarget);
@@ -1211,6 +1267,9 @@ static int renameResolveTrigger(Parse *pParse, const char *zDb){
          sNC.ncFlags = 0;
        }
        sNC.pSrcList = 0;
+        sqlite3SrcListDelete(db, pSrc);
+      }else{
+        rc = SQLITE_NOMEM;
      }
    }
  }
@@ -1239,6 +1298,12 @@ static void renameWalkTrigger(Walker *pWalker, Trigger *pTrigger){
      sqlite3WalkExpr(pWalker, pUpsert->pUpsertWhere);
      sqlite3WalkExpr(pWalker, pUpsert->pUpsertTargetWhere);
    }
+    if( pStep->pFrom ){
+      int i;
+      for(i=0; i<pStep->pFrom->nSrc; i++){
+        sqlite3WalkSelect(pWalker, pStep->pFrom->a[i].pSelect);
+      }
+    }
  }
 }

@@ -1329,7 +1394,7 @@ static void renameColumnFunc(
 #ifndef SQLITE_OMIT_AUTHORIZATION
  db->xAuth = 0;
 #endif
-  rc = renameParseSql(&sParse, zDb, db, zSql, bTemp);
+  rc = renameParseSql(&sParse, zDb, db, zSql, bTemp, 0);

  /* Find tokens that need to be replaced. */
  memset(&sWalker, 0, sizeof(Walker));
@@ -1371,12 +1436,12 @@ static void renameColumnFunc(
        for(pIdx=sParse.pNewIndex; pIdx; pIdx=pIdx->pNext){
          sqlite3WalkExprList(&sWalker, pIdx->aColExpr);
        }
-      }
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
-      for(i=0; i<sParse.pNewTable->nCol; i++){
-        sqlite3WalkExpr(&sWalker, sParse.pNewTable->aCol[i].pDflt);
-      }
+        for(i=0; i<sParse.pNewTable->nCol; i++){
+          sqlite3WalkExpr(&sWalker, sParse.pNewTable->aCol[i].pDflt);
+        }
 #endif
+      }

      for(pFKey=sParse.pNewTable->pFKey; pFKey; pFKey=pFKey->pNextFrom){
        for(i=0; i<pFKey->nCol; i++){
@@ -1397,7 +1462,7 @@ static void renameColumnFunc(
  }else{
    /* A trigger */
    TriggerStep *pStep;
-    rc = renameResolveTrigger(&sParse, (bTemp ? 0 : zDb));
+    rc = renameResolveTrigger(&sParse);
    if( rc!=SQLITE_OK ) goto renameColumnFunc_done;

    for(pStep=sParse.pNewTrigger->step_list; pStep; pStep=pStep->pNext){
@@ -1430,7 +1495,7 @@ static void renameColumnFunc(
 renameColumnFunc_done:
  if( rc!=SQLITE_OK ){
    if( sParse.zErrMsg ){
-      renameColumnParseError(context, 0, argv[1], argv[2], &sParse);
+      renameColumnParseError(context, "", argv[1], argv[2], &sParse);
    }else{
      sqlite3_result_error_code(context, rc);
    }
@@ -1468,7 +1533,7 @@ static int renameTableSelectCb(Walker *pWalker, Select *pSelect){
    return WRC_Abort;
  }
  for(i=0; i<pSrc->nSrc; i++){
-    struct SrcList_item *pItem = &pSrc->a[i];
+    SrcItem *pItem = &pSrc->a[i];
    if( pItem->pTab==p->pTab ){
      renameTokenFind(pWalker->pParse, p, pItem->zName);
    }
@@ -1533,7 +1598,7 @@ static void renameTableFunc(
    sWalker.xSelectCallback = renameTableSelectCb;
    sWalker.u.pRename = &sCtx;

-    rc = renameParseSql(&sParse, zDb, db, zInput, bTemp);
+    rc = renameParseSql(&sParse, zDb, db, zInput, bTemp, 0);

    if( rc==SQLITE_OK ){
      int isLegacy = (db->flags & SQLITE_LegacyAlter);
@@ -1600,7 +1665,7 @@ static void renameTableFunc(
        }

        if( isLegacy==0 ){
-          rc = renameResolveTrigger(&sParse, bTemp ? 0 : zDb);
+          rc = renameResolveTrigger(&sParse);
          if( rc==SQLITE_OK ){
            renameWalkTrigger(&sWalker, pTrigger);
            for(pStep=pTrigger->step_list; pStep; pStep=pStep->pNext){
@@ -1619,7 +1684,7 @@ static void renameTableFunc(
    }
    if( rc!=SQLITE_OK ){
      if( sParse.zErrMsg ){
-        renameColumnParseError(context, 0, argv[1], argv[2], &sParse);
+        renameColumnParseError(context, "", argv[1], argv[2], &sParse);
      }else{
        sqlite3_result_error_code(context, rc);
      }
@@ -1648,6 +1713,8 @@ static void renameTableFunc(
 **   2: Object type ("view", "table", "trigger" or "index").
 **   3: Object name.
 **   4: True if object is from temp schema.
+**   5: "when" part of error message.
+**   6: Name of column being dropped, or NULL.
 **
 ** Unless it finds an error, this function normally returns NULL. However, it
 ** returns integer value 1 if:
@@ -1665,6 +1732,8 @@ static void renameTableTest(
  char const *zInput = (const char*)sqlite3_value_text(argv[1]);
  int bTemp = sqlite3_value_int(argv[4]);
  int isLegacy = (db->flags & SQLITE_LegacyAlter);
+  char const *zWhen = (const char*)sqlite3_value_text(argv[5]);
+  char const *zDropColumn = (const char*)sqlite3_value_text(argv[6]);

 #ifndef SQLITE_OMIT_AUTHORIZATION
  sqlite3_xauth xAuth = db->xAuth;
@@ -1675,7 +1744,7 @@ static void renameTableTest(
  if( zDb && zInput ){
    int rc;
    Parse sParse;
-    rc = renameParseSql(&sParse, zDb, db, zInput, bTemp);
+    rc = renameParseSql(&sParse, zDb, db, zInput, bTemp, zDropColumn);
    if( rc==SQLITE_OK ){
      if( isLegacy==0 && sParse.pNewTable && sParse.pNewTable->pSelect ){
        NameContext sNC;
@@ -1687,7 +1756,7 @@ static void renameTableTest(

      else if( sParse.pNewTrigger ){
        if( isLegacy==0 ){
-          rc = renameResolveTrigger(&sParse, bTemp ? 0 : zDb);
+          rc = renameResolveTrigger(&sParse);
        }
        if( rc==SQLITE_OK ){
          int i1 = sqlite3SchemaToIndex(db, sParse.pNewTrigger->pTabSchema);
@@ -1697,8 +1766,8 @@ static void renameTableTest(
      }
    }

-    if( rc!=SQLITE_OK ){
-      renameColumnParseError(context, 1, argv[2], argv[3], &sParse);
+    if( rc!=SQLITE_OK && zWhen ){
+      renameColumnParseError(context, zWhen, argv[2], argv[3],&sParse);
    }
    renameParseCleanup(&sParse);
  }
@@ -1708,14 +1777,206 @@ static void renameTableTest(
 #endif
 }

+/*
+** The implementation of internal UDF sqlite_drop_column().
+** 
+** Arguments:
+**
+**  argv[0]: An integer - the index of the schema containing the table
+**  argv[1]: CREATE TABLE statement to modify.
+**  argv[2]: An integer - the index of the column to remove.
+**
+** The value returned is a string containing the CREATE TABLE statement
+** with column argv[2] removed.
+*/
+static void dropColumnFunc(
+  sqlite3_context *context,
+  int NotUsed,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  int iSchema = sqlite3_value_int(argv[0]);
+  const char *zSql = (const char*)sqlite3_value_text(argv[1]);
+  int iCol = sqlite3_value_int(argv[2]);
+  const char *zDb = db->aDb[iSchema].zDbSName;
+  int rc;
+  Parse sParse;
+  RenameToken *pCol;
+  Table *pTab;
+  const char *zEnd;
+  char *zNew = 0;
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  sqlite3_xauth xAuth = db->xAuth;
+  db->xAuth = 0;
+#endif
+
+  UNUSED_PARAMETER(NotUsed);
+  rc = renameParseSql(&sParse, zDb, db, zSql, iSchema==1, 0);
+  if( rc!=SQLITE_OK ) goto drop_column_done;
+  pTab = sParse.pNewTable;
+  if( pTab==0 || pTab->nCol==1 || iCol>=pTab->nCol ){ 
+    /* This can happen if the sqlite_schema table is corrupt */
+    rc = SQLITE_CORRUPT_BKPT;
+    goto drop_column_done;
+  }
+
+  pCol = renameTokenFind(&sParse, 0, (void*)pTab->aCol[iCol].zName);
+  if( iCol<pTab->nCol-1 ){
+    RenameToken *pEnd;
+    pEnd = renameTokenFind(&sParse, 0, (void*)pTab->aCol[iCol+1].zName);
+    zEnd = (const char*)pEnd->t.z;
+  }else{
+    zEnd = (const char*)&zSql[pTab->addColOffset];
+    while( ALWAYS(pCol->t.z[0]!=0) && pCol->t.z[0]!=',' ) pCol->t.z--;
+  }
+
+  zNew = sqlite3MPrintf(db, "%.*s%s", pCol->t.z-zSql, zSql, zEnd);
+  sqlite3_result_text(context, zNew, -1, SQLITE_TRANSIENT);
+  sqlite3_free(zNew);
+
+drop_column_done:
+  renameParseCleanup(&sParse);
+#ifndef SQLITE_OMIT_AUTHORIZATION
+  db->xAuth = xAuth;
+#endif
+  if( rc!=SQLITE_OK ){
+    sqlite3_result_error_code(context, rc);
+  }
+}
+
+/*
+** This function is called by the parser upon parsing an 
+**
+**     ALTER TABLE pSrc DROP COLUMN pName
+**
+** statement. Argument pSrc contains the possibly qualified name of the
+** table being edited, and token pName the name of the column to drop.
+*/
+void sqlite3AlterDropColumn(Parse *pParse, SrcList *pSrc, Token *pName){
+  sqlite3 *db = pParse->db;       /* Database handle */
+  Table *pTab;                    /* Table to modify */
+  int iDb;                        /* Index of db containing pTab in aDb[] */
+  const char *zDb;                /* Database containing pTab ("main" etc.) */
+  char *zCol = 0;                 /* Name of column to drop */
+  int iCol;                       /* Index of column zCol in pTab->aCol[] */
+
+  /* Look up the table being altered. */
+  assert( pParse->pNewTable==0 );
+  assert( sqlite3BtreeHoldsAllMutexes(db) );
+  if( NEVER(db->mallocFailed) ) goto exit_drop_column;
+  pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]);
+  if( !pTab ) goto exit_drop_column;
+
+  /* Make sure this is not an attempt to ALTER a view, virtual table or 
+  ** system table. */
+  if( SQLITE_OK!=isAlterableTable(pParse, pTab) ) goto exit_drop_column;
+  if( SQLITE_OK!=isRealTable(pParse, pTab, 1) ) goto exit_drop_column;
+
+  /* Find the index of the column being dropped. */
+  zCol = sqlite3NameFromToken(db, pName);
+  if( zCol==0 ){
+    assert( db->mallocFailed );
+    goto exit_drop_column;
+  }
+  iCol = sqlite3ColumnIndex(pTab, zCol);
+  if( iCol<0 ){
+    sqlite3ErrorMsg(pParse, "no such column: \"%s\"", zCol);
+    goto exit_drop_column;
+  }
+
+  /* Do not allow the user to drop a PRIMARY KEY column or a column 
+  ** constrained by a UNIQUE constraint.  */
+  if( pTab->aCol[iCol].colFlags & (COLFLAG_PRIMKEY|COLFLAG_UNIQUE) ){
+    sqlite3ErrorMsg(pParse, "cannot drop %s column: \"%s\"", 
+        (pTab->aCol[iCol].colFlags&COLFLAG_PRIMKEY) ? "PRIMARY KEY" : "UNIQUE",
+        zCol
+    );
+    goto exit_drop_column;
+  }
+
+  /* Do not allow the number of columns to go to zero */
+  if( pTab->nCol<=1 ){
+    sqlite3ErrorMsg(pParse, "cannot drop column \"%s\": no other columns exist",zCol);
+    goto exit_drop_column;
+  }
+
+  /* Edit the sqlite_schema table */
+  iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+  assert( iDb>=0 );
+  zDb = db->aDb[iDb].zDbSName;
+  renameTestSchema(pParse, zDb, iDb==1, "", 0);
+  sqlite3NestedParse(pParse, 
+      "UPDATE \"%w\"." DFLT_SCHEMA_TABLE " SET "
+      "sql = sqlite_drop_column(%d, sql, %d) "
+      "WHERE (type=='table' AND tbl_name=%Q COLLATE nocase)"
+      , zDb, iDb, iCol, pTab->zName
+  );
+
+  /* Drop and reload the database schema. */
+  renameReloadSchema(pParse, iDb, INITFLAG_AlterDrop);
+  renameTestSchema(pParse, zDb, iDb==1, "after drop column", zCol);
+
+  /* Edit rows of table on disk */
+  if( pParse->nErr==0 && (pTab->aCol[iCol].colFlags & COLFLAG_VIRTUAL)==0 ){
+    int i;
+    int addr;
+    int reg;
+    int regRec;
+    Index *pPk = 0;
+    int nField = 0;               /* Number of non-virtual columns after drop */
+    int iCur;
+    Vdbe *v = sqlite3GetVdbe(pParse);
+    iCur = pParse->nTab++;
+    sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite);
+    addr = sqlite3VdbeAddOp1(v, OP_Rewind, iCur); VdbeCoverage(v);
+    reg = ++pParse->nMem;
+    pParse->nMem += pTab->nCol;
+    if( HasRowid(pTab) ){
+      sqlite3VdbeAddOp2(v, OP_Rowid, iCur, reg);
+    }else{
+      pPk = sqlite3PrimaryKeyIndex(pTab);
+    }
+    for(i=0; i<pTab->nCol; i++){
+      if( i!=iCol && (pTab->aCol[i].colFlags & COLFLAG_VIRTUAL)==0 ){
+        int regOut;
+        if( pPk ){
+          int iPos = sqlite3TableColumnToIndex(pPk, i);
+          int iColPos = sqlite3TableColumnToIndex(pPk, iCol);
+          regOut = reg+1+iPos-(iPos>iColPos);
+        }else{
+          regOut = reg+1+nField;
+        }
+        sqlite3ExprCodeGetColumnOfTable(v, pTab, iCur, i, regOut);
+        nField++;
+      }
+    }
+    regRec = reg + pTab->nCol;
+    sqlite3VdbeAddOp3(v, OP_MakeRecord, reg+1, nField, regRec);
+    if( pPk ){
+      sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iCur, regRec, reg+1, pPk->nKeyCol);
+    }else{
+      sqlite3VdbeAddOp3(v, OP_Insert, iCur, regRec, reg);
+    }
+
+    sqlite3VdbeAddOp2(v, OP_Next, iCur, addr+1); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addr);
+  }
+
+exit_drop_column:
+  sqlite3DbFree(db, zCol);
+  sqlite3SrcListDelete(db, pSrc);
+}
+
 /*
 ** Register built-in functions used to help implement ALTER TABLE
 */
 void sqlite3AlterFunctions(void){
  static FuncDef aAlterTableFuncs[] = {
-    INTERNAL_FUNCTION(sqlite_rename_column, 9, renameColumnFunc),
-    INTERNAL_FUNCTION(sqlite_rename_table,  7, renameTableFunc),
-    INTERNAL_FUNCTION(sqlite_rename_test,   5, renameTableTest),
+    INTERNAL_FUNCTION(sqlite_rename_column,  9, renameColumnFunc),
+    INTERNAL_FUNCTION(sqlite_rename_table,   7, renameTableFunc),
+    INTERNAL_FUNCTION(sqlite_rename_test,    7, renameTableTest),
+    INTERNAL_FUNCTION(sqlite_drop_column,    3, dropColumnFunc),
  };
  sqlite3InsertBuiltinFuncs(aAlterTableFuncs, ArraySize(aAlterTableFuncs));
 }
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .32.0
 .35.4