Version 3.34.1

FossilOrigin-Name: 10e20c0b43500cfb9bbc0eaa061c57514f715d87238f4d835880cd846b9ebd1f
Fix an issue with sha3_query() when the first argument contains blank
2021-01-20 14:10:07 +00:00 · 2021-01-19 20:38:13 +00:00 · 2021-01-19 20:17:46 +00:00 · 2021-01-19 20:09:44 +00:00 · 2021-01-19 20:04:37 +00:00 · 2020-12-16 13:20:15 +00:00
177 changed files with 6770 additions and 1293 deletions
@@ -441,6 +441,7 @@ TESTSRC += \
  $(TOP)/ext/expert/test_expert.c \
  $(TOP)/ext/misc/amatch.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 \
@@ -1086,6 +1087,7 @@ SHELL_SRC = \
        $(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 \
@@ -1232,6 +1234,7 @@ 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
@@ -1558,6 +1558,7 @@ TESTEXT = \
  $(TOP)\ext\expert\test_expert.c \
  $(TOP)\ext\misc\amatch.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 \
@@ -2208,6 +2209,7 @@ SHELL_SRC = \
        $(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 \
@@ -2386,6 +2388,7 @@ 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)
@@ -1 +1 @@
-3.33.0
+3.34.1
@@ -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 3.33.0.
+# Generated by GNU Autoconf 2.69 for sqlite 3.34.1.
 #
 #
 # 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='3.33.0'
-PACKAGE_STRING='sqlite 3.33.0'
+PACKAGE_VERSION='3.34.1'
+PACKAGE_STRING='sqlite 3.34.1'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''

@@ -799,7 +799,6 @@ TEMP_STORE
 ALLOWRELEASE
 SQLITE_THREADSAFE
 BUILD_CC
-VERSION_NUMBER
 RELEASE
 VERSION
 program_prefix
@@ -1467,7 +1466,7 @@ 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 3.33.0 to adapt to many kinds of systems.
+\`configure' configures sqlite 3.34.1 to adapt to many kinds of systems.

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

@@ -1532,7 +1531,7 @@ fi

 if test -n "$ac_init_help"; then
  case $ac_init_help in
-     short | recursive ) echo "Configuration of sqlite 3.33.0:";;
+     short | recursive ) echo "Configuration of sqlite 3.34.1:";;
   esac
  cat <<\_ACEOF

@@ -1659,7 +1658,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
  cat <<\_ACEOF
-sqlite configure 3.33.0
+sqlite configure 3.34.1
 generated by GNU Autoconf 2.69

 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -2078,7 +2077,7 @@ 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 3.33.0, which was
+It was created by sqlite $as_me 3.34.1, which was
 generated by GNU Autoconf 2.69.  Invocation command line was

  $ $0 $@
@@ -3936,13 +3935,13 @@ 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:3938: $ac_compile\"" >&5)
  (eval "$ac_compile" 2>conftest.err)
  cat conftest.err >&5
-  (eval echo "\"\$as_me:3942: $NM \\\"conftest.$ac_objext\\\"\"" >&5)
+  (eval echo "\"\$as_me:3941: $NM \\\"conftest.$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:3944: output\"" >&5)
  cat conftest.out >&5
  if $GREP 'External.*some_variable' conftest.out > /dev/null; then
    lt_cv_nm_interface="MS dumpbin"
@@ -5148,7 +5147,7 @@ ia64-*-hpux*)
  ;;
 *-*-irix6*)
  # Find out which ABI we are using.
-  echo '#line 5151 "configure"' > conftest.$ac_ext
+  echo '#line 5150 "configure"' > conftest.$ac_ext
  if { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_compile\""; } >&5
  (eval $ac_compile) 2>&5
  ac_status=$?
@@ -6673,11 +6672,11 @@ 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:6675: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:6680: \$? = $ac_status" >&5
+   echo "$as_me:6679: \$? = $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 +7011,11 @@ 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:7014: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>conftest.err)
   ac_status=$?
   cat conftest.err >&5
-   echo "$as_me:7019: \$? = $ac_status" >&5
+   echo "$as_me:7018: \$? = $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 +7116,11 @@ 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:7119: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:7124: \$? = $ac_status" >&5
+   echo "$as_me:7123: \$? = $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 +7171,11 @@ 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:7174: $lt_compile\"" >&5)
   (eval "$lt_compile" 2>out/conftest.err)
   ac_status=$?
   cat out/conftest.err >&5
-   echo "$as_me:7179: \$? = $ac_status" >&5
+   echo "$as_me:7178: \$? = $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 +9551,7 @@ 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 9554 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -9648,7 +9647,7 @@ 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 9650 "configure"
 #include "confdefs.h"

 #if HAVE_DLFCN_H
@@ -10388,12 +10387,6 @@ 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
@@ -12243,7 +12236,7 @@ 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 3.33.0, which was
+This file was extended by sqlite $as_me 3.34.1, which was
 generated by GNU Autoconf 2.69.  Invocation command line was

  CONFIG_FILES    = $CONFIG_FILES
@@ -12309,7 +12302,7 @@ _ACEOF
 cat >>$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 3.33.0
+sqlite config.status 3.34.1
 configured by $0, generated by GNU Autoconf 2.69,
  with options \\"\$ac_cs_config\\"

@@ -155,11 +155,6 @@ 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
@@ -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.
@@ -326,6 +326,47 @@ 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>?)
+}
+
 }

 proc do_candidates_test {tn sql res} {
@@ -685,6 +685,7 @@ 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);
  while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(p1) ){
@@ -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;

@@ -1719,10 +1721,12 @@ 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_schema", 0, 0, 0);
@@ -3479,7 +3479,7 @@ static int fts3ColumnMethod(
        break;
      }else{
        iCol = p->nColumn;
-        /* fall-through */
+        /* no break */ deliberate_fall_through
      }

    default:
@@ -3722,9 +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 ){
@@ -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
@@ -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);
  }

@@ -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.
 */
@@ -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);
@@ -4997,7 +4997,9 @@ static void fts5MergePrefixLists(
        ** at most 20 bytes of unexpected space. */
        fts5MergeAppendDocid(&out, iLastRowid, i2.iRowid);
        fts5BufferZero(&tmp);
-        sqlite3Fts5BufferSize(&p->rc, &tmp, i1.nPoslist + i2.nPoslist + 10 + 10);
+        sqlite3Fts5BufferSize(&p->rc, &tmp, 
+            i1.nPoslist + i2.nPoslist + 10 + 10 + FTS5_DATA_ZERO_PADDING
+        );
        if( p->rc ) break;

        sqlite3Fts5PoslistNext64(a1, i1.nPoslist, &iOff1, &iPos1);
@@ -5071,9 +5073,10 @@ static void fts5MergePrefixLists(
    }
    assert_nc( out.n<=(p1->n+p2->n+9) );

-    fts5BufferSet(&p->rc, p1, out.n, out.p);
+    fts5BufferFree(p1);
    fts5BufferFree(&tmp);
-    fts5BufferFree(&out);
+    memset(&out.p[out.n], 0, FTS5_DATA_ZERO_PADDING);
+    *p1 = out;
  }
 }

@@ -6059,7 +6062,7 @@ 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 +6123,7 @@ 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 +6134,7 @@ 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);
@@ -2671,8 +2709,7 @@ int sqlite3Fts5GetTokenizer(
  Fts5Global *pGlobal, 
  const char **azArg,
  int nArg,
-  Fts5Tokenizer **ppTok,
-  fts5_tokenizer **ppTokApi,
+  Fts5Config *pConfig,
  char **pzErr
 ){
  Fts5TokenizerModule *pMod;
@@ -2684,16 +2721,22 @@ 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[1], (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);
@@ -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
@@ -9691,7 +9691,7 @@ do_test 65.0 {

 do_catchsql_test 65.1 {
  SELECT ( MATCH (t1,591)) FROM t1 WHERE t1 MATCH 'e*eŸ'
-} {1 {database disk image is malformed}}
+} {1 {malformed database schema (t2) - invalid rootpage}}

 #-------------------------------------------------------------------------
 #
@@ -10324,6 +10324,190 @@ do_catchsql_test 69.2 {
  SELECT * FROM t1 WHERE a MATCH 'fx*'
 } {1 {database disk image is malformed}}

+#-------------------------------------------------------------------------
+reset_db
+do_test 70.0 {
+  sqlite3 db {}
+  db deserialize [decode_hexdb {
+.open --hexdb
+| size 24576 pagesize 4096 filename sql022250.txt.db
+| page 1 offset 0
+|      0: 53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00   SQLite format 3.
+|     16: 10 00 01 01 00 40 20 20 00 00 00 00 00 00 00 00   .....@  ........
+|     96: 00 00 00 00 0d 00 00 00 06 0d e2 00 0f c4 0f 6a   ...............j
+|    112: 0e fc 0e 9d 0e 3d 0d e2 00 00 00 00 00 00 00 00   .....=..........
+|   3552: 00 00 59 06 06 17 21 21 01 7f 74 61 62 6c 65 74   ..Y...!!..tablet
+|   3568: 74 74 5f 63 6f 6e 66 69 67 74 74 74 5f 63 6f 6e   tt_configttt_con
+|   3584: 66 69 67 06 43 52 45 41 54 45 20 54 41 42 4c 45   fig.CREATE TABLE
+|   3600: 20 27 74 74 74 5f 63 6f 6e 66 69 67 27 28 6b 20    'ttt_config'(k 
+|   3616: 50 52 49 4d 41 52 59 20 4b 45 59 2c 20 76 29 20   PRIMARY KEY, v) 
+|   3632: 57 49 54 48 4f 55 54 20 52 4f 57 49 44 5e 15 07   WITHOUT ROWID^..
+|   3648: 17 23 23 01 81 03 74 61 62 6c 65 74 74 74 5f 64   .##...tablettt_d
+|   3664: 6f 63 73 69 7a 65 74 74 74 5f 64 6f 63 73 69 7a   ocsizettt_docsiz
+|   3680: 65 05 43 52 45 41 54 45 20 54 41 42 4c 45 20 27   e.CREATE TABLE '
+|   3696: 74 74 74 5f 64 6f 63 73 69 7a 65 27 28 69 64 20   ttt_docsize'(id 
+|   3712: 49 4d 54 45 47 45 52 20 50 52 49 4d 41 52 59 20   IMTEGER PRIMARY 
+|   3728: 4b 45 59 2c 20 73 7a 20 42 4c 4f 20 29 5d 04 07   KEY, sz BLO )]..
+|   3744: 17 23 23 01 81 01 74 61 62 6c 65 74 74 74 5f 63   .##...tablettt_c
+|   3760: 6f 6e 74 65 6e 74 74 74 74 5f 63 6f 6e 74 65 6e   ontentttt_conten
+|   3776: 74 04 43 52 45 41 54 45 20 54 41 42 4c 45 20 27   t.CREATE TABLE '
+|   3792: 74 74 74 5f 63 6f 6e 74 65 6e 74 27 28 69 64 20   ttt_content'(id 
+|   3808: 49 4e 54 45 47 45 52 20 50 52 49 4d 41 52 59 20   INTEGER PRIMARY 
+|   3824: 4b 45 59 2c 20 63 30 2c 20 63 31 29 6c 03 07 17   KEY, c0, c1)l...
+|   3840: 1b 1b 01 81 2f 74 61 62 6c 65 74 74 74 5f 69 64   ..../tablettt_id
+|   3856: 78 74 74 74 5f 69 64 78 03 43 52 45 41 54 45 20   xttt_idx.CREATE 
+|   3872: 54 41 42 4c 45 20 27 74 74 74 5f 69 64 78 27 28   TABLE 'ttt_idx'(
+|   3888: 73 65 67 69 64 2c 20 74 65 72 6d 2c 20 70 67 6e   segid, term, pgn
+|   3904: 6f 2c 20 50 52 49 4d 41 52 59 20 4b 45 59 28 73   o, PRIMARY KEY(s
+|   3920: 65 67 69 64 2c 20 74 65 72 6d 29 29 20 57 49 54   egid, term)) WIT
+|   3936: 48 4f 55 54 20 52 4f 57 49 44 58 02 07 17 1d 1d   HOUT ROWIDX.....
+|   3952: 01 81 03 74 61 62 6c 65 74 74 74 5f 64 61 74 61   ...tablettt_data
+|   3968: 74 74 74 5f 64 61 74 61 02 43 52 45 41 54 45 20   ttt_data.CREATE 
+|   3984: 54 41 42 4c 45 20 27 74 74 74 5f 64 61 74 61 27   TABLE 'ttt_data'
+|   4000: 28 69 64 20 49 4e 54 45 47 45 52 20 50 52 49 4d   (id INTEGER PRIM
+|   4016: 41 52 59 20 4b 45 59 2c 20 62 6c 6f 63 6b 20 42   ARY KEY, block B
+|   4032: 4c 4f 42 29 3a 01 06 17 13 13 08 5f 74 61 62 6c   LOB):......_tabl
+|   4048: 65 74 74 74 74 74 74 43 52 45 41 54 45 20 56 49   ettttttCREATE VI
+|   4064: 52 54 55 41 4c 20 54 41 42 4c 45 20 74 74 74 20   RTUAL TABLE ttt 
+|   4080: 55 53 49 4e 47 20 66 74 73 35 28 61 2c 20 62 29   USING fts5(a, b)
+| page 2 offset 4096
+|      0: 0d 0f 54 00 05 0e 81 00 0f e7 0e 81 0f af 0f 58   ..T............X
+|     16: 0e 98 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
+|   3712: 00 15 0a 03 00 30 00 00 00 00 01 03 03 00 03 01   .....0..........
+|   3728: 01 01 02 01 01 03 01 01 81 24 8c 80 80 80 80 01   .........$......
+|   3744: 04 00 82 4c 00 00 00 9b 02 30 65 03 1a 02 05 05   ...L.....0e.....
+|   3760: 07 05 01 01 04 03 03 08 03 03 01 2e 02 05 05 07   ................
+|   3776: 05 07 05 07 05 01 01 14 03 03 08 03 03 08 03 bf   ................
+|   3792: 07 f2 f3 02 01 65 03 1e 03 05 05 04 05 05 01 01   .....e..........
+|   3808: 03 06 04 04 06 04 03 01 36 03 05 05 04 05 05 04   ........6.......
+|   3824: 05 15 04 05 05 01 01 03 06 04 04 06 04 04 a1 04   ................
+|   3840: 04 06 04 03 03 01 65 03 14 04 05 07 05 05 01 01   ......e.........
+|   3856: 02 09 0a 01 20 04 05 07 05 07 05 07 05 05 01 01   .... ...........
+|   3872: 02 0f da 0a 0a 04 01 64 f3 02 0a 01 06 0a 0a 0a   .......d........
+|   3888: 05 01 65 03 06 01 01 0a 01 0a 01 01 0a 0a 0a 04   ..e.............
+|   3904: 2b 31 21 0b 0f ef 00 14 2a 00 00 00 00 01 02 02   +1!.....*.......
+|   3920: 00 02 01 01 01 02 01 01 50 88 80 80 80 80 01 04   ........P.......
+|   3936: 00 81 24 00 00 00 47 01 30 65 02 1a 02 05 05 07   ..$...G.0e......
+|   3952: 05 01 01 04 03 03 08 03 03 02 01 65 02 1d f3 05   ...........e....
+|   3968: 05 04 05 05 01 01 04 06 04 04 06 04 03 03 01 65   ...............e
+|   3984: 02 14 04 05 07 05 05 01 01 02 08 0a 04 01 65 02   ..............e.
+|   4000: 02 0a 05 01 65 02 06 01 01 0a 04 12 14 0f 06 31   ....e..........1
+|   4016: 84 80 80 80 80 01 03 00 68 00 00 00 2b 02 30 65   ........h...+.0e
+|   4032: 01 10 02 05 05 01 01 04 03 03 02 01 66 01 12 03   ............f...
+|   4048: 05 05 01 01 03 06 04 03 03 01 65 01 0e 04 05 05   ..........e.....
+|   4064: 01 01 02 08 04 0d 0e 06 01 03 00 12 04 4c 4c 00   .............LL.
+|   4080: 00 00 11 24 00 00 00 00 01 01 01 00 01 01 01 01   ...$............
+| page 3 offset 8192
+|      0: 0a 2f 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ./..............
+| page 4 offset 12288
+|   3344: 00 00 00 00 00 00 00 00 00 00 81 52 04 06 10 81   ...........R....
+|   3360: 5d 81 55 65 20 65 65 20 65 65 65 20 65 20 65 65   ].Ue ee eee e ee
+|   3376: 20 65 65 65 20 65 20 65 65 20 65 65 65 65 20 65    eee e ee eeee e
+|   3392: 65 20 65 65 65 24 a5 20 65 65 20 65 65 65 20 65   e eee$. ee eee e
+|   3408: 24 05 65 20 65 65 65 65 20 65 65 20 65 65 65 20   $.e eeee ee eee 
+|   3424: 65 20 65 65 20 65 65 65 20 65 20 65 65 20 65 65   e ee eee e ee ee
+|   3440: 65 65 20 65 65 20 65 65 65 20 65 20 65 65 10 65   ee ee eee e ee.e
+|   3456: 65 65 20 65 20 65 65 20 65 65 65 65 65 65 20 65   ee e ee eeeeee e
+|   3472: 65 20 65 20 65 20 65 20 65 65 20 65 65 65 20 65   e e e e ee eee e
+|   3488: 1f 20 65 65 66 65 65 20 65 65 20 65 20 65 20 2d   . eefee ee e e -
+| page 5 offset 16384
+|   4064: 00 00 00 00 05 04 d0 00 10 21 21 05 03 03 00 10   .........!!.....
+|   4080: 11 11 05 02 03 00 10 11 10 05 01 03 00 10 09 09   ................
+| page 6 offset 20480
+|      0: 0a 00 00 00 01 0f f4 00 0f f4 00 00 00 00 00 00   ................
+|   4080: 00 00 00 00 0b 03 1b 01 76 65 72 73 69 6f 6e 04   ........version.
+| end sql022250.txt.db
+}]} {}
+
+do_catchsql_test 70.1 {
+  SELECT snippet(ttt, -1, '', '','','>')FROM ttt('e* NOT ee*e* NOT ee*');
+} {1 {database disk image is malformed}}
+
+do_catchsql_test 70.2 {
+  SELECT snippet(ttt, -1, '', '','',13)FROM ttt('e* NOT ee*e* NOT ee*')
+} {1 {database disk image is malformed}}
+
+#-------------------------------------------------------------------------
+reset_db
+do_test 71.0 {
+  sqlite3 db {}
+  db deserialize [decode_hexdb {
+.open --hexdb
+| size 28672 pagesize 4096 filename sql025294.txt.db
+| page 1 offset 0
+|      0: 53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00   SQLite format 3.
+|     16: 10 00 00 01 00 40 20 20 00 00 00 00 00 00 00 07   .....@  ........
+|     96: 00 00 00 00 0d 00 00 00 07 0d d2 00 0f c4 0f 6d   ...............m
+|    112: 0f 02 0e ab 0e 4e 0d f6 0d d2 00 00 00 00 00 00   .....N..........
+|   3536: 00 00 22 07 06 17 11 11 01 31 74 61 62 6c 65 74   .........1tablet
+|   3552: 32 74 32 07 43 52 45 41 54 45 20 54 41 42 4c 45   2t2.CREATE TABLE
+|   3568: 20 74 32 28 78 29 56 06 06 17 1f 1f 01 7d 74 61    t2(x)V.......ta
+|   3584: 62 6c 65 74 31 5f 63 6f 6e 66 69 67 74 31 5f 63   blet1_configt1_c
+|   3600: 6f 6e 66 69 67 06 43 52 45 41 54 45 20 54 41 42   onfig.CREATE TAB
+|   3616: 4c 45 20 27 74 31 5f 63 6f 6e 66 69 67 27 28 6b   LE 't1_config'(k
+|   3632: 20 50 52 49 4d 41 52 59 20 4b 45 59 2c 20 76 29    PRIMARY KEY, v)
+|   3648: 20 57 49 54 48 4f 55 54 20 52 4f 57 49 44 5b 05    WITHOUT ROWID[.
+|   3664: 07 17 21 21 01 81 01 74 61 62 6c 65 74 31 5f 64   ..!!...tablet1_d
+|   3680: 6f 63 73 69 7a 65 74 31 5f 64 6f 63 73 69 7a 65   ocsizet1_docsize
+|   3696: 05 43 52 45 41 54 45 20 54 41 42 4c 45 20 27 74   .CREATE TABLE 't
+|   3712: 31 5f 64 6f 63 73 69 7a 65 27 28 69 64 20 49 4e   1_docsize'(id IN
+|   3728: 54 45 47 45 52 20 50 52 49 4d 41 52 59 20 4b 45   TEGER PRIMARY KE
+|   3744: 59 2c 20 73 7a 20 42 4c 4f 42 29 55 04 06 17 21   Y, sz BLOB)U...!
+|   3760: 21 01 77 74 61 62 6c 65 74 31 5f 63 6f 6e 74 65   !.wtablet1_conte
+|   3776: 6e 74 74 31 5f 63 6f 6e 74 65 6e 74 04 43 52 45   ntt1_content.CRE
+|   3792: 41 54 45 20 54 41 42 4c 45 20 27 74 31 5f 63 6f   ATE TABLE 't1_co
+|   3808: 6e 74 65 6e 74 27 28 69 64 20 49 4e 54 45 47 45   ntent'(id INTEGE
+|   3824: 52 20 50 52 49 4d 41 52 59 20 4b 45 59 2c 20 63   R PRIMARY KEY, c
+|   3840: 30 29 69 03 07 17 19 19 01 81 2d 74 61 62 6c 65   0)i.......-table
+|   3856: 74 31 5f 69 64 78 74 31 5f 69 64 78 03 43 52 45   t1_idxt1_idx.CRE
+|   3872: 41 54 45 20 54 41 42 4c 45 20 27 74 31 5f 69 64   ATE TABLE 't1_id
+|   3888: 78 27 28 73 65 67 69 64 2c 20 74 65 72 6d 2c 20   x'(segid, term, 
+|   3904: 70 67 6e 6f 2c 20 50 52 49 4d 41 52 59 20 4b 45   pgno, PRIMARY KE
+|   3920: 59 28 73 65 67 69 64 2c 20 74 65 72 6d 29 29 20   Y(segid, term)) 
+|   3936: 57 49 54 48 4f 55 54 20 52 4f 57 49 44 55 02 07   WITHOUT ROWIDU..
+|   3952: 17 1b 1b 01 81 01 74 61 62 6c 65 74 31 5f 64 61   ......tablet1_da
+|   3968: 74 61 74 31 5f 64 61 74 61 02 43 52 45 41 54 45   tat1_data.CREATE
+|   3984: 20 54 41 42 4c 45 20 27 74 31 5f 64 61 74 61 27    TABLE 't1_data'
+|   4000: 28 69 64 20 49 4e 54 45 47 45 52 20 50 52 49 4d   (id INTEGER PRIM
+|   4016: 41 52 58 20 4b 45 59 2c 20 62 6c 6f 63 6b 20 42   ARX KEY, block B
+|   4032: 4c 4f 42 29 3a 01 06 17 11 11 08 63 74 61 62 6c   LOB):......ctabl
+|   4048: 65 74 31 74 31 43 52 45 41 54 45 20 56 49 52 54   et1t1CREATE VIRT
+|   4064: 55 41 4c 20 54 41 42 4c 45 20 74 31 20 55 53 49   UAL TABLE t1 USI
+|   4080: 4e 47 20 66 74 73 35 28 63 6f 6e 74 65 6e 74 29   NG fts5(content)
+| page 2 offset 4096
+|      0: 0d 00 00 00 03 0f bd 00 0f e8 0f ef 0f bd 00 00   ................
+|   4016: 00 00 00 00 00 00 00 00 00 00 00 00 00 24 84 80   .............$..
+|   4032: 80 80 80 01 03 00 4e 00 00 00 1e 06 30 61 62 61   ......N.....0aba
+|   4048: 60 eb 01 02 02 04 01 66 74 02 02 02 04 04 6e 64   `......ft.....nd
+|   4064: 6f 6e 03 01 f2 04 1a 07 05 01 03 00 10 03 03 0f   on..............
+|   4080: 0a 03 00 24 00 00 00 00 01 01 4b 00 01 01 01 01   ...$......K.....
+| page 3 offset 8192
+|      0: 0a 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................
+|   4080: 00 00 00 00 00 00 00 00 00 00 05 04 09 0c 01 02   ................
+| page 4 offset 12288
+|      0: 0d 00 00 00 03 0f e0 00 0f f6 0f ec 0f e0 00 00   ................
+|   4064: 0a 03 03 00 1b 61 62 61 6e 64 6f 6e 08 02 03 00   .....abandon....
+|   4080: 17 61 62 61 66 74 08 01 03 00 17 61 62 61 63 6b   .abaft.....aback
+| page 5 offset 16384
+|      0: 0d 00 00 00 03 0f ee 00 0f fa 0f f4 0f ee 00 00   ................
+|   4064: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 04 03   ................
+|   4080: 03 00 0e 01 04 02 03 00 0e 01 04 01 03 00 0e 01   ................
+| page 6 offset 20480
+|      0: 0a 00 00 00 01 0f f4 00 0f f4 00 00 00 00 00 00   ................
+|   4080: 00 00 00 00 0b 03 1b 01 76 65 72 73 69 6f 6e 04   ........version.
+| page 7 offset 24576
+|      0: 0d 00 00 00 03 0f d6 00 0f f4 0f e1 00 00 00 00   ................
+|   4048: 00 00 00 00 00 00 09 03 02 1b 72 65 62 75 69 6c   ..........rebuil
+|   4064: 64 11 02 02 2b 69 6e 74 65 67 72 69 74 79 2d 63   d...+integrity-c
+|   4080: 68 65 63 6b 0a 01 02 1d 6f 70 74 69 6d 69 7a 65   heck....optimize
+| end sql025294.txt.db
+}]} {}
+
+do_catchsql_test 71.2 {
+  INSERT INTO t1(t1) VALUES('integrity-check');
+} {1 {database disk image is malformed}}
+
+
 sqlite3_fts5_may_be_corrupt 0
 finish_test

@@ -50,4 +50,47 @@ 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}}
+
+
+
 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
 }

@@ -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
@@ -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
@@ -395,7 +398,9 @@ 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 +439,9 @@ 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 +611,20 @@ 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;
 }

 /*
@@ -763,6 +777,13 @@ 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)
@@ -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;
 }
@@ -599,7 +599,6 @@ int sqlite3_decimal_init(
  const sqlite3_api_routines *pApi
 ){
  int rc = SQLITE_OK;
-  SQLITE_EXTENSION_INIT2(pApi);
  static const struct {
    const char *zFuncName;
    int nArg;
@@ -614,6 +613,8 @@ int sqlite3_decimal_init(
  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,
@@ -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.
@@ -460,7 +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: {
@@ -601,7 +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;
@@ -2304,6 +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;
@@ -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;
@@ -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));
@@ -250,11 +255,12 @@ 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{
@@ -311,7 +317,7 @@ 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 +331,7 @@ 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++){
@@ -398,6 +405,10 @@ static sqlite3_module seriesModule = {
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
+  0,                         /* xSavepoint */
+  0,                         /* xRelease */
+  0,                         /* xRollbackTo */
+  0                          /* xShadowName */
 };

 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -621,9 +621,11 @@ 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) ){
@@ -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;
 }

@@ -1075,7 +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 ){
@@ -759,7 +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;
@@ -2956,8 +2956,13 @@ 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);
 }

@@ -227,7 +227,7 @@ 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;
@@ -1131,7 +1131,7 @@ 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 +1248,7 @@ static int SQLITE_TCLAPI test_sqlite3session_config(
  int objc,
  Tcl_Obj *CONST objv[]
 ){
-  struct ConfigOpt {
+  static struct ConfigOpt {
    const char *zSub;
    int op;
  } aSub[] = {
@@ -361,6 +361,7 @@ TESTSRC = \
 TESTSRC += \
  $(TOP)/ext/misc/amatch.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 \
@@ -912,6 +913,7 @@ 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)                            \
@@ -1 +1 @@
-af07d8458ae5e2933134b706f80f9538f011970221904bf9f50ed6e47d306e14
+10e20c0b43500cfb9bbc0eaa061c57514f715d87238f4d835880cd846b9ebd1f
@@ -1194,15 +1194,23 @@ static int renameResolveTrigger(Parse *pParse){
      SrcList *pSrc = sqlite3TriggerStepSrc(pParse, pStep);
      if( pSrc ){
        int i;
-        for(i=0; i<pSrc->nSrc; i++){
+        for(i=0; i<pSrc->nSrc && rc==SQLITE_OK; i++){
          struct SrcList_item *p = &pSrc->a[i];
-          p->pTab = sqlite3LocateTableItem(pParse, 0, p);
          p->iCursor = pParse->nTab++;
-          if( p->pTab==0 ){
-            rc = SQLITE_ERROR;
+          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->nTabRef++;
-            rc = sqlite3ViewGetColumnNames(pParse, p->pTab);
+            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;
@@ -1264,6 +1272,12 @@ 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);
+      }
+    }
  }
 }

@@ -1772,6 +1772,7 @@ static int loadStatTbl(
    }
    pSpace = (tRowcnt*)&pIdx->aSample[nSample];
    pIdx->aAvgEq = pSpace; pSpace += nIdxCol;
+    pIdx->pTable->tabFlags |= TF_HasStat4;
    for(i=0; i<nSample; i++){
      pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol;
      pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol;
@@ -293,7 +293,9 @@ static void detachFunc(
    sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);
    goto detach_error;
  }
-  if( sqlite3BtreeIsInReadTrans(pDb->pBt) || sqlite3BtreeIsInBackup(pDb->pBt) ){
+  if( sqlite3BtreeTxnState(pDb->pBt)!=SQLITE_TXN_NONE
+   || sqlite3BtreeIsInBackup(pDb->pBt)
+  ){
    sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
    goto detach_error;
  }
@@ -123,7 +123,7 @@ static int setDestPgsz(sqlite3_backup *p){
 ** message in database handle db.
 */
 static int checkReadTransaction(sqlite3 *db, Btree *p){
-  if( sqlite3BtreeIsInReadTrans(p) ){
+  if( sqlite3BtreeTxnState(p)!=SQLITE_TXN_NONE ){
    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use");
    return SQLITE_ERROR;
  }
@@ -354,7 +354,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
    ** one now. If a transaction is opened here, then it will be closed
    ** before this function exits.
    */
-    if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){
+    if( rc==SQLITE_OK && SQLITE_TXN_NONE==sqlite3BtreeTxnState(p->pSrc) ){
      rc = sqlite3BtreeBeginTrans(p->pSrc, 0, 0);
      bCloseTrans = 1;
    }
@@ -726,7 +726,7 @@ int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
  sqlite3BtreeEnter(pTo);
  sqlite3BtreeEnter(pFrom);

-  assert( sqlite3BtreeIsInTrans(pTo) );
+  assert( sqlite3BtreeTxnState(pTo)==SQLITE_TXN_WRITE );
  pFd = sqlite3PagerFile(sqlite3BtreePager(pTo));
  if( pFd->pMethods ){
    i64 nByte = sqlite3BtreeGetPageSize(pFrom)*(i64)sqlite3BtreeLastPage(pFrom);
@@ -762,7 +762,7 @@ int sqlite3BtreeCopyFile(Btree *pTo, Btree *pFrom){
    sqlite3PagerClearCache(sqlite3BtreePager(b.pDest));
  }

-  assert( sqlite3BtreeIsInTrans(pTo)==0 );
+  assert( sqlite3BtreeTxnState(pTo)!=SQLITE_TXN_WRITE );
 copy_finished:
  sqlite3BtreeLeave(pFrom);
  sqlite3BtreeLeave(pTo);
@@ -112,6 +112,17 @@ int sqlite3_enable_shared_cache(int enable){
  #define hasReadConflicts(a, b) 0
 #endif

+#ifdef SQLITE_DEBUG
+/*
+** Return and reset the seek counter for a Btree object.
+*/
+sqlite3_uint64 sqlite3BtreeSeekCount(Btree *pBt){
+  u64 n =  pBt->nSeek;
+  pBt->nSeek = 0;
+  return n;
+}
+#endif
+
 /*
 ** Implementation of the SQLITE_CORRUPT_PAGE() macro. Takes a single
 ** (MemPage*) as an argument. The (MemPage*) must not be NULL.
@@ -2605,7 +2616,7 @@ btree_open_out:
    ** do not change the pager-cache size.
    */
    if( sqlite3BtreeSchema(p, 0, 0)==0 ){
-      sqlite3PagerSetCachesize(p->pBt->pPager, SQLITE_DEFAULT_CACHE_SIZE);
+      sqlite3BtreeSetCacheSize(p, SQLITE_DEFAULT_CACHE_SIZE);
    }

    pFile = sqlite3PagerFile(pBt->pPager);
@@ -5459,6 +5470,10 @@ int sqlite3BtreeMovetoUnpacked(
    }
  }

+#ifdef SQLITE_DEBUG
+  pCur->pBtree->nSeek++;   /* Performance measurement during testing */
+#endif
+
  if( pIdxKey ){
    xRecordCompare = sqlite3VdbeFindCompare(pIdxKey);
    pIdxKey->errCode = 0;
@@ -5735,7 +5750,7 @@ static SQLITE_NOINLINE int btreeNext(BtCursor *pCur){

  pPage = pCur->pPage;
  idx = ++pCur->ix;
-  if( !pPage->isInit ){
+  if( !pPage->isInit || sqlite3FaultSim(412) ){
    /* The only known way for this to happen is for there to be a
    ** recursive SQL function that does a DELETE operation as part of a
    ** SELECT which deletes content out from under an active cursor
@@ -10262,8 +10277,8 @@ char *sqlite3BtreeIntegrityCheck(
         (PTRMAP_PAGENO(pBt, i)==i && pBt->autoVacuum) ){
        checkAppendMsg(&sCheck, "Pointer map page %d is referenced", i);
      }
-    }
 #endif
+    }
  }

  /* Clean  up and report errors.
@@ -10310,11 +10325,12 @@ const char *sqlite3BtreeGetJournalname(Btree *p){
 }

 /*
-** Return non-zero if a transaction is active.
+** Return one of SQLITE_TXN_NONE, SQLITE_TXN_READ, or SQLITE_TXN_WRITE
+** to describe the current transaction state of Btree p.
 */
-int sqlite3BtreeIsInTrans(Btree *p){
+int sqlite3BtreeTxnState(Btree *p){
  assert( p==0 || sqlite3_mutex_held(p->db->mutex) );
-  return (p && (p->inTrans==TRANS_WRITE));
+  return p ? p->inTrans : 0;
 }

 #ifndef SQLITE_OMIT_WAL
@@ -10343,14 +10359,8 @@ int sqlite3BtreeCheckpoint(Btree *p, int eMode, int *pnLog, int *pnCkpt){
 #endif

 /*
-** Return non-zero if a read (or write) transaction is active.
+** Return true if there is currently a backup running on Btree p.
 */
-int sqlite3BtreeIsInReadTrans(Btree *p){
-  assert( p );
-  assert( sqlite3_mutex_held(p->db->mutex) );
-  return p->inTrans!=TRANS_NONE;
-}
-
 int sqlite3BtreeIsInBackup(Btree *p){
  assert( p );
  assert( sqlite3_mutex_held(p->db->mutex) );
@@ -85,16 +85,24 @@ int sqlite3BtreeCommit(Btree*);
 int sqlite3BtreeRollback(Btree*,int,int);
 int sqlite3BtreeBeginStmt(Btree*,int);
 int sqlite3BtreeCreateTable(Btree*, Pgno*, int flags);
-int sqlite3BtreeIsInTrans(Btree*);
-int sqlite3BtreeIsInReadTrans(Btree*);
+int sqlite3BtreeTxnState(Btree*);
 int sqlite3BtreeIsInBackup(Btree*);
+
 void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
 int sqlite3BtreeSchemaLocked(Btree *pBtree);
 #ifndef SQLITE_OMIT_SHARED_CACHE
 int sqlite3BtreeLockTable(Btree *pBtree, int iTab, u8 isWriteLock);
 #endif
+
+/* Savepoints are named, nestable SQL transactions mostly implemented */ 
+/* in vdbe.c and pager.c See https://sqlite.org/lang_savepoint.html */
 int sqlite3BtreeSavepoint(Btree *, int, int);

+/* "Checkpoint" only refers to WAL. See https://sqlite.org/wal.html#ckpt */
+#ifndef SQLITE_OMIT_WAL
+  int sqlite3BtreeCheckpoint(Btree*, int, int *, int *);  
+#endif
+
 const char *sqlite3BtreeGetFilename(Btree *);
 const char *sqlite3BtreeGetJournalname(Btree *);
 int sqlite3BtreeCopyFile(Btree *, Btree *);
@@ -331,6 +339,12 @@ int sqlite3BtreeCursorHasHint(BtCursor*, unsigned int mask);
 int sqlite3BtreeIsReadonly(Btree *pBt);
 int sqlite3HeaderSizeBtree(void);

+#ifdef SQLITE_DEBUG
+sqlite3_uint64 sqlite3BtreeSeekCount(Btree*);
+#else
+# define sqlite3BtreeSeekCount(X) 0
+#endif
+
 #ifndef NDEBUG
 int sqlite3BtreeCursorIsValid(BtCursor*);
 #endif
@@ -353,6 +353,9 @@ struct Btree {
  u32 iDataVersion;  /* Combines with pBt->pPager->iDataVersion */
  Btree *pNext;      /* List of other sharable Btrees from the same db */
  Btree *pPrev;      /* Back pointer of the same list */
+#ifdef SQLITE_DEBUG
+  u64 nSeek;         /* Calls to sqlite3BtreeMovetoUnpacked() */
+#endif
 #ifndef SQLITE_OMIT_SHARED_CACHE
  BtLock lock;       /* Object used to lock page 1 */
 #endif
@@ -364,11 +367,25 @@ struct Btree {
 ** If the shared-data extension is enabled, there may be multiple users
 ** of the Btree structure. At most one of these may open a write transaction,
 ** but any number may have active read transactions.
+**
+** These values must match SQLITE_TXN_NONE, SQLITE_TXN_READ, and
+** SQLITE_TXN_WRITE
 */
 #define TRANS_NONE  0
 #define TRANS_READ  1
 #define TRANS_WRITE 2

+#if TRANS_NONE!=SQLITE_TXN_NONE
+# error wrong numeric code for no-transaction
+#endif
+#if TRANS_READ!=SQLITE_TXN_READ
+# error wrong numeric code for read-transaction
+#endif
+#if TRANS_WRITE!=SQLITE_TXN_WRITE
+# error wrong numeric code for write-transaction
+#endif
+
+
 /*
 ** An instance of this object represents a single database file.
 ** 
@@ -53,7 +53,7 @@ void sqlite3TableLock(
  u8 isWriteLock,    /* True for a write lock */
  const char *zName  /* Name of the table to be locked */
 ){
-  Parse *pToplevel = sqlite3ParseToplevel(pParse);
+  Parse *pToplevel;
  int i;
  int nBytes;
  TableLock *p;
@@ -61,6 +61,7 @@ void sqlite3TableLock(

  if( iDb==1 ) return;
  if( !sqlite3BtreeSharable(pParse->db->aDb[iDb].pBt) ) return;
+  pToplevel = sqlite3ParseToplevel(pParse);
  for(i=0; i<pToplevel->nTableLock; i++){
    p = &pToplevel->aTableLock[i];
    if( p->iDb==iDb && p->iTab==iTab ){
@@ -90,10 +91,8 @@ void sqlite3TableLock(
 */
 static void codeTableLocks(Parse *pParse){
  int i;
-  Vdbe *pVdbe; 
-
-  pVdbe = sqlite3GetVdbe(pParse);
-  assert( pVdbe!=0 ); /* sqlite3GetVdbe cannot fail: VDBE already allocated */
+  Vdbe *pVdbe = pParse->pVdbe; 
+  assert( pVdbe!=0 );

  for(i=0; i<pParse->nTableLock; i++){
    TableLock *p = &pParse->aTableLock[i];
@@ -1618,8 +1617,10 @@ primary_key_exit:
 ** Add a new CHECK constraint to the table currently under construction.
 */
 void sqlite3AddCheckConstraint(
-  Parse *pParse,    /* Parsing context */
-  Expr *pCheckExpr  /* The check expression */
+  Parse *pParse,      /* Parsing context */
+  Expr *pCheckExpr,   /* The check expression */
+  const char *zStart, /* Opening "(" */
+  const char *zEnd    /* Closing ")" */
 ){
 #ifndef SQLITE_OMIT_CHECK
  Table *pTab = pParse->pNewTable;
@@ -1630,6 +1631,13 @@ void sqlite3AddCheckConstraint(
    pTab->pCheck = sqlite3ExprListAppend(pParse, pTab->pCheck, pCheckExpr);
    if( pParse->constraintName.n ){
      sqlite3ExprListSetName(pParse, pTab->pCheck, &pParse->constraintName, 1);
+    }else{
+      Token t;
+      for(zStart++; sqlite3Isspace(zStart[0]); zStart++){}
+      while( sqlite3Isspace(zEnd[-1]) ){ zEnd--; }
+      t.z = zStart;
+      t.n = (int)(zEnd - t.z);
+      sqlite3ExprListSetName(pParse, pTab->pCheck, &t, 1);    
    }
  }else
 #endif
@@ -1648,7 +1656,7 @@ void sqlite3AddCollateType(Parse *pParse, Token *pToken){
  char *zColl;              /* Dequoted name of collation sequence */
  sqlite3 *db;

-  if( (p = pParse->pNewTable)==0 ) return;
+  if( (p = pParse->pNewTable)==0 || IN_RENAME_OBJECT ) return;
  i = p->nCol-1;
  db = pParse->db;
  zColl = sqlite3NameFromToken(db, pToken);
@@ -1883,12 +1891,15 @@ static int resizeIndexObject(sqlite3 *db, Index *pIdx, int N){
  int nByte;
  if( pIdx->nColumn>=N ) return SQLITE_OK;
  assert( pIdx->isResized==0 );
-  nByte = (sizeof(char*) + sizeof(i16) + 1)*N;
+  nByte = (sizeof(char*) + sizeof(LogEst) + sizeof(i16) + 1)*N;
  zExtra = sqlite3DbMallocZero(db, nByte);
  if( zExtra==0 ) return SQLITE_NOMEM_BKPT;
  memcpy(zExtra, pIdx->azColl, sizeof(char*)*pIdx->nColumn);
  pIdx->azColl = (const char**)zExtra;
  zExtra += sizeof(char*)*N;
+  memcpy(zExtra, pIdx->aiRowLogEst, sizeof(LogEst)*(pIdx->nKeyCol+1));
+  pIdx->aiRowLogEst = (LogEst*)zExtra;
+  zExtra += sizeof(LogEst)*N;
  memcpy(zExtra, pIdx->aiColumn, sizeof(i16)*pIdx->nColumn);
  pIdx->aiColumn = (i16*)zExtra;
  zExtra += sizeof(i16)*N;
@@ -2703,10 +2714,8 @@ int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
  assert( pTable->pSelect );
  pSel = sqlite3SelectDup(db, pTable->pSelect, 0);
  if( pSel ){
-#ifndef SQLITE_OMIT_ALTERTABLE
    u8 eParseMode = pParse->eParseMode;
    pParse->eParseMode = PARSE_MODE_NORMAL;
-#endif
    n = pParse->nTab;
    sqlite3SrcListAssignCursors(pParse, pSel->pSrc);
    pTable->nCol = -1;
@@ -2754,9 +2763,7 @@ int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
    sqlite3DeleteTable(db, pSelTab);
    sqlite3SelectDelete(db, pSel);
    EnableLookaside;
-#ifndef SQLITE_OMIT_ALTERTABLE
    pParse->eParseMode = eParseMode;
-#endif
  } else {
    nErr++;
  }
@@ -4094,7 +4101,7 @@ void sqlite3DefaultRowEst(Index *pIdx){
  ** table but other parts we are having to guess at, then do not let the
  ** estimated number of rows in the table be less than 1000 (LogEst 99).
  ** Failure to do this can cause the indexes for which we do not have
-  ** stat1 data to be ignored by the query planner.  tag-20200527-1
+  ** stat1 data to be ignored by the query planner.
  */
  x = pIdx->pTable->nRowLogEst;
  assert( 99==sqlite3LogEst(1000) );
@@ -4453,7 +4460,7 @@ void sqlite3SrcListAssignCursors(Parse *pParse, SrcList *pList){
  assert(pList || pParse->db->mallocFailed );
  if( pList ){
    for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
-      if( pItem->iCursor>=0 ) break;
+      if( pItem->iCursor>=0 ) continue;
      pItem->iCursor = pParse->nTab++;
      if( pItem->pSelect ){
        sqlite3SrcListAssignCursors(pParse, pItem->pSelect->pSrc);
@@ -4470,15 +4477,15 @@ void sqlite3SrcListDelete(sqlite3 *db, SrcList *pList){
  struct SrcList_item *pItem;
  if( pList==0 ) return;
  for(pItem=pList->a, i=0; i<pList->nSrc; i++, pItem++){
-    sqlite3DbFree(db, pItem->zDatabase);
+    if( pItem->zDatabase ) sqlite3DbFreeNN(db, pItem->zDatabase);
    sqlite3DbFree(db, pItem->zName);
-    sqlite3DbFree(db, pItem->zAlias);
+    if( pItem->zAlias ) sqlite3DbFreeNN(db, pItem->zAlias);
    if( pItem->fg.isIndexedBy ) sqlite3DbFree(db, pItem->u1.zIndexedBy);
    if( pItem->fg.isTabFunc ) sqlite3ExprListDelete(db, pItem->u1.pFuncArg);
    sqlite3DeleteTable(db, pItem->pTab);
-    sqlite3SelectDelete(db, pItem->pSelect);
-    sqlite3ExprDelete(db, pItem->pOn);
-    sqlite3IdListDelete(db, pItem->pUsing);
+    if( pItem->pSelect ) sqlite3SelectDelete(db, pItem->pSelect);
+    if( pItem->pOn ) sqlite3ExprDelete(db, pItem->pOn);
+    if( pItem->pUsing ) sqlite3IdListDelete(db, pItem->pUsing);
  }
  sqlite3DbFreeNN(db, pList);
 }
@@ -4650,7 +4657,16 @@ void sqlite3BeginTransaction(Parse *pParse, int type){
  if( !v ) return;
  if( type!=TK_DEFERRED ){
    for(i=0; i<db->nDb; i++){
-      sqlite3VdbeAddOp2(v, OP_Transaction, i, (type==TK_EXCLUSIVE)+1);
+      int eTxnType;
+      Btree *pBt = db->aDb[i].pBt;
+      if( pBt && sqlite3BtreeIsReadonly(pBt) ){
+        eTxnType = 0;  /* Read txn */
+      }else if( type==TK_EXCLUSIVE ){
+        eTxnType = 2;  /* Exclusive txn */
+      }else{
+        eTxnType = 1;  /* Write txn */
+      }
+      sqlite3VdbeAddOp2(v, OP_Transaction, i, eTxnType);
      sqlite3VdbeUsesBtree(v, i);
    }
  }
@@ -4739,13 +4755,11 @@ int sqlite3OpenTempDatabase(Parse *pParse){
 ** will occur at the end of the top-level VDBE and will be generated
 ** later, by sqlite3FinishCoding().
 */
-void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
-  Parse *pToplevel = sqlite3ParseToplevel(pParse);
-
-  assert( iDb>=0 && iDb<pParse->db->nDb );
-  assert( pParse->db->aDb[iDb].pBt!=0 || iDb==1 );
+static void sqlite3CodeVerifySchemaAtToplevel(Parse *pToplevel, int iDb){
+  assert( iDb>=0 && iDb<pToplevel->db->nDb );
+  assert( pToplevel->db->aDb[iDb].pBt!=0 || iDb==1 );
  assert( iDb<SQLITE_MAX_ATTACHED+2 );
-  assert( sqlite3SchemaMutexHeld(pParse->db, iDb, 0) );
+  assert( sqlite3SchemaMutexHeld(pToplevel->db, iDb, 0) );
  if( DbMaskTest(pToplevel->cookieMask, iDb)==0 ){
    DbMaskSet(pToplevel->cookieMask, iDb);
    if( !OMIT_TEMPDB && iDb==1 ){
@@ -4753,6 +4767,10 @@ void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
    }
  }
 }
+void sqlite3CodeVerifySchema(Parse *pParse, int iDb){
+  sqlite3CodeVerifySchemaAtToplevel(sqlite3ParseToplevel(pParse), iDb);
+}
+

 /*
 ** If argument zDb is NULL, then call sqlite3CodeVerifySchema() for each 
@@ -4784,7 +4802,7 @@ void sqlite3CodeVerifyNamedSchema(Parse *pParse, const char *zDb){
 */
 void sqlite3BeginWriteOperation(Parse *pParse, int setStatement, int iDb){
  Parse *pToplevel = sqlite3ParseToplevel(pParse);
-  sqlite3CodeVerifySchema(pParse, iDb);
+  sqlite3CodeVerifySchemaAtToplevel(pToplevel, iDb);
  DbMaskSet(pToplevel->writeMask, iDb);
  pToplevel->isMultiWrite |= setStatement;
 }
@@ -4835,7 +4853,9 @@ void sqlite3HaltConstraint(
  i8 p4type,        /* P4_STATIC or P4_TRANSIENT */
  u8 p5Errmsg       /* P5_ErrMsg type */
 ){
-  Vdbe *v = sqlite3GetVdbe(pParse);
+  Vdbe *v;
+  assert( pParse->pVdbe!=0 );
+  v = sqlite3GetVdbe(pParse);
  assert( (errCode&0xff)==SQLITE_CONSTRAINT || pParse->nested );
  if( onError==OE_Abort ){
    sqlite3MayAbort(pParse);
@@ -425,7 +425,7 @@ void sqlite3DeleteFrom(
  }else
 #endif /* SQLITE_OMIT_TRUNCATE_OPTIMIZATION */
  {
-    u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK|WHERE_SEEK_TABLE;
+    u16 wcf = WHERE_ONEPASS_DESIRED|WHERE_DUPLICATES_OK;
    if( sNC.ncFlags & NC_VarSelect ) bComplex = 1;
    wcf |= (bComplex ? 0 : WHERE_ONEPASS_MULTIROW);
    if( HasRowid(pTab) ){
@@ -461,6 +461,9 @@ void sqlite3DeleteFrom(
    assert( IsVirtual(pTab)==0 || eOnePass!=ONEPASS_MULTI );
    assert( IsVirtual(pTab) || bComplex || eOnePass!=ONEPASS_OFF );
    if( eOnePass!=ONEPASS_SINGLE ) sqlite3MultiWrite(pParse);
+    if( sqlite3WhereUsesDeferredSeek(pWInfo) ){
+      sqlite3VdbeAddOp1(v, OP_FinishSeek, iTabCur);
+    }
  
    /* Keep track of the number of rows to be deleted */
    if( memCnt ){
@@ -495,6 +498,7 @@ void sqlite3DeleteFrom(
      if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iTabCur] = 0;
      if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iTabCur] = 0;
      if( addrEphOpen ) sqlite3VdbeChangeToNoop(v, addrEphOpen);
+      addrBypass = sqlite3VdbeMakeLabel(pParse);
    }else{
      if( pPk ){
        /* Add the PK key for this row to the temporary table */
@@ -508,13 +512,6 @@ void sqlite3DeleteFrom(
        nKey = 1;  /* OP_DeferredSeek always uses a single rowid */
        sqlite3VdbeAddOp2(v, OP_RowSetAdd, iRowSet, iKey);
      }
-    }
-  
-    /* If this DELETE cannot use the ONEPASS strategy, this is the 
-    ** end of the WHERE loop */
-    if( eOnePass!=ONEPASS_OFF ){
-      addrBypass = sqlite3VdbeMakeLabel(pParse);
-    }else{
      sqlite3WhereEnd(pWInfo);
    }
  
@@ -945,10 +942,6 @@ int sqlite3GenerateIndexKey(
  }
  if( regOut ){
    sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut);
-    if( pIdx->pTable->pSelect ){
-      const char *zAff = sqlite3IndexAffinityStr(pParse->db, pIdx);
-      sqlite3VdbeChangeP4(v, -1, zAff, P4_TRANSIENT);
-    }
  }
  sqlite3ReleaseTempRange(pParse, regBase, nCol);
  return regBase;
@@ -44,8 +44,10 @@ char sqlite3TableColumnAffinity(Table *pTab, int iCol){
 */
 char sqlite3ExprAffinity(const Expr *pExpr){
  int op;
-  while( ExprHasProperty(pExpr, EP_Skip) ){
-    assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
+  while( ExprHasProperty(pExpr, EP_Skip|EP_IfNullRow) ){
+    assert( pExpr->op==TK_COLLATE
+         || pExpr->op==TK_IF_NULL_ROW
+         || (pExpr->op==TK_REGISTER && pExpr->op2==TK_IF_NULL_ROW) );
    pExpr = pExpr->pLeft;
    assert( pExpr!=0 );
  }
@@ -115,7 +117,7 @@ Expr *sqlite3ExprAddCollateString(Parse *pParse, Expr *pExpr, const char *zC){
 */
 Expr *sqlite3ExprSkipCollate(Expr *pExpr){
  while( pExpr && ExprHasProperty(pExpr, EP_Skip) ){
-    assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
+    assert( pExpr->op==TK_COLLATE );
    pExpr = pExpr->pLeft;
  }   
  return pExpr;
@@ -134,7 +136,7 @@ Expr *sqlite3ExprSkipCollateAndLikely(Expr *pExpr){
      assert( pExpr->op==TK_FUNCTION );
      pExpr = pExpr->x.pList->a[0].pExpr;
    }else{
-      assert( pExpr->op==TK_COLLATE || pExpr->op==TK_IF_NULL_ROW );
+      assert( pExpr->op==TK_COLLATE );
      pExpr = pExpr->pLeft;
    }
  }   
@@ -768,6 +770,7 @@ int sqlite3SelectExprHeight(Select *p){
 ** Expr.flags. 
 */
 void sqlite3ExprSetHeightAndFlags(Parse *pParse, Expr *p){
+  if( pParse->nErr ) return;
  if( p && p->x.pList && !ExprHasProperty(p, EP_xIsSelect) ){
    p->flags |= EP_Propagate & sqlite3ExprListFlags(p->x.pList);
  }
@@ -2029,7 +2032,7 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
      if( sqlite3ExprIdToTrueFalse(pExpr) ){
        return WRC_Prune;
      }
-      /* Fall thru */
+      /* no break */ deliberate_fall_through
    case TK_COLUMN:
    case TK_AGG_FUNCTION:
    case TK_AGG_COLUMN:
@@ -2043,7 +2046,7 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
      if( pWalker->eCode==3 && pExpr->iTable==pWalker->u.iCur ){
        return WRC_Continue;
      }
-      /* Fall through */
+      /* no break */ deliberate_fall_through
    case TK_IF_NULL_ROW:
    case TK_REGISTER:
    case TK_DOT:
@@ -2064,7 +2067,7 @@ static int exprNodeIsConstant(Walker *pWalker, Expr *pExpr){
        pWalker->eCode = 0;
        return WRC_Abort;
      }
-      /* Fall through */
+      /* no break */ deliberate_fall_through
    default:
      testcase( pExpr->op==TK_SELECT ); /* sqlite3SelectWalkFail() disallows */
      testcase( pExpr->op==TK_EXISTS ); /* sqlite3SelectWalkFail() disallows */
@@ -3620,6 +3623,7 @@ void sqlite3ExprCodeMove(Parse *pParse, int iFrom, int iTo, int nReg){
 */
 static void exprToRegister(Expr *pExpr, int iReg){
  Expr *p = sqlite3ExprSkipCollateAndLikely(pExpr);
+  if( NEVER(p==0) ) return;
  p->op2 = p->op;
  p->op = TK_REGISTER;
  p->iTable = iReg;
@@ -3836,6 +3840,7 @@ expr_code_doover:
        return target;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
+      /* no break */ deliberate_fall_through
    }
    case TK_COLUMN: {
      int iTab = pExpr->iTable;
@@ -4606,6 +4611,7 @@ int sqlite3ExprCodeTemp(Parse *pParse, Expr *pExpr, int *pReg){
  int r2;
  pExpr = sqlite3ExprSkipCollateAndLikely(pExpr);
  if( ConstFactorOk(pParse)
+   && ALWAYS(pExpr!=0)
   && pExpr->op!=TK_REGISTER
   && sqlite3ExprIsConstantNotJoin(pExpr)
  ){
@@ -4901,7 +4907,7 @@ void sqlite3ExprIfTrue(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
      testcase( op==TK_ISNOT );
      op = (op==TK_IS) ? TK_EQ : TK_NE;
      jumpIfNull = SQLITE_NULLEQ;
-      /* Fall thru */
+      /* no break */ deliberate_fall_through
    case TK_LT:
    case TK_LE:
    case TK_GT:
@@ -5077,7 +5083,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
      testcase( pExpr->op==TK_ISNOT );
      op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;
      jumpIfNull = SQLITE_NULLEQ;
-      /* Fall thru */
+      /* no break */ deliberate_fall_through
    case TK_LT:
    case TK_LE:
    case TK_GT:
@@ -5389,13 +5395,13 @@ static int exprImpliesNotNull(
    case TK_RSHIFT: 
    case TK_CONCAT: 
      seenNot = 1;
-      /* Fall thru */
+      /* no break */ deliberate_fall_through
    case TK_STAR:
    case TK_REM:
    case TK_BITAND:
    case TK_SLASH: {
      if( exprImpliesNotNull(pParse, p->pRight, pNN, iTab, seenNot) ) return 1;
-      /* Fall thru into the next case */
+      /* no break */ deliberate_fall_through
    }
    case TK_SPAN:
    case TK_COLLATE:
@@ -5544,6 +5550,7 @@ static int impliesNotNullRow(Walker *pWalker, Expr *pExpr){
      ){
        return WRC_Prune;
      }
+      /* no break */ deliberate_fall_through
    }
    default:
      return WRC_Continue;
@@ -1359,6 +1359,7 @@ static Trigger *fkActionTrigger(
          pStep->op = TK_DELETE; 
          break; 
        }
+        /* no break */ deliberate_fall_through
      default:
        pStep->op = TK_UPDATE;
    }
@@ -1995,6 +1995,8 @@ void sqlite3RegisterBuiltinFunctions(void){
    FUNCTION(zeroblob,           1, 0, 0, zeroblobFunc     ),
    FUNCTION(substr,             2, 0, 0, substrFunc       ),
    FUNCTION(substr,             3, 0, 0, substrFunc       ),
+    FUNCTION(substring,          2, 0, 0, substrFunc       ),
+    FUNCTION(substring,          3, 0, 0, substrFunc       ),
    WAGGREGATE(sum,   1,0,0, sumStep, sumFinalize, sumFinalize, sumInverse, 0),
    WAGGREGATE(total, 1,0,0, sumStep,totalFinalize,totalFinalize,sumInverse, 0),
    WAGGREGATE(avg,   1,0,0, sumStep, avgFinalize, avgFinalize, sumInverse, 0),
@@ -303,7 +303,7 @@ int sqlite3PendingByte = 0x40000000;
 /*
 ** Flags for select tracing and the ".selecttrace" macro of the CLI
 */
-/**/ u32 sqlite3SelectTrace = 0;
+u32 sqlite3_unsupported_selecttrace = 0;

 #include "opcodes.h"
 /*
@@ -32,7 +32,8 @@ void sqlite3OpenTable(
 ){
  Vdbe *v;
  assert( !IsVirtual(pTab) );
-  v = sqlite3GetVdbe(pParse);
+  assert( pParse->pVdbe!=0 );
+  v = pParse->pVdbe;
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(pParse, iDb, pTab->tnum, 
                   (opcode==OP_OpenWrite)?1:0, pTab->zName);
@@ -1531,7 +1532,7 @@ void sqlite3GenerateConstraintChecks(

  isUpdate = regOldData!=0;
  db = pParse->db;
-  v = sqlite3GetVdbe(pParse);
+  v = pParse->pVdbe;
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  nCol = pTab->nCol;
@@ -1612,7 +1613,7 @@ void sqlite3GenerateConstraintChecks(
          }
          case OE_Abort:
            sqlite3MayAbort(pParse);
-            /* Fall through */
+            /* no break */ deliberate_fall_through
          case OE_Rollback:
          case OE_Fail: {
            char *zMsg = sqlite3MPrintf(db, "%s.%s", pTab->zName,
@@ -1685,7 +1686,7 @@ void sqlite3GenerateConstraintChecks(
        sqlite3VdbeGoto(v, ignoreDest);
      }else{
        char *zName = pCheck->a[i].zEName;
-        if( zName==0 ) zName = pTab->zName;
+        assert( zName!=0 || pParse->db->mallocFailed );
        if( onError==OE_Replace ) onError = OE_Abort; /* IMP: R-26383-51744 */
        sqlite3HaltConstraint(pParse, SQLITE_CONSTRAINT_CHECK,
                              onError, zName, P4_TRANSIENT,
@@ -1840,7 +1841,7 @@ void sqlite3GenerateConstraintChecks(
    switch( onError ){
      default: {
        onError = OE_Abort;
-        /* Fall thru into the next case */
+        /* no break */ deliberate_fall_through
      }
      case OE_Rollback:
      case OE_Abort:
@@ -1901,7 +1902,7 @@ void sqlite3GenerateConstraintChecks(
 #ifndef SQLITE_OMIT_UPSERT
      case OE_Update: {
        sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, 0, iDataCur);
-        /* Fall through */
+        /* no break */ deliberate_fall_through
      }
 #endif
      case OE_Ignore: {
@@ -2122,7 +2123,7 @@ void sqlite3GenerateConstraintChecks(
 #ifndef SQLITE_OMIT_UPSERT
      case OE_Update: {
        sqlite3UpsertDoUpdate(pParse, pUpsert, pTab, pIdx, iIdxCur+ix);
-        /* Fall through */
+        /* no break */ deliberate_fall_through
      }
 #endif
      case OE_Ignore: {
@@ -2304,7 +2305,7 @@ void sqlite3CompleteInsertion(
       || update_flags==(OPFLAG_ISUPDATE|OPFLAG_SAVEPOSITION)
  );

-  v = sqlite3GetVdbe(pParse);
+  v = pParse->pVdbe;
  assert( v!=0 );
  assert( pTab->pSelect==0 );  /* This table is not a VIEW */
  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
@@ -2405,7 +2406,7 @@ int sqlite3OpenTableAndIndices(
    return 0;
  }
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
-  v = sqlite3GetVdbe(pParse);
+  v = pParse->pVdbe;
  assert( v!=0 );
  if( iBase<0 ) iBase = pParse->nTab;
  iDataCur = iBase++;
@@ -478,6 +478,8 @@ static const sqlite3_api_routines sqlite3Apis = {
  sqlite3_create_filename,
  sqlite3_free_filename,
  sqlite3_database_file_object,
+  /* Version 3.34.0 and later */
+  sqlite3_txn_state,
 };

 /* True if x is the directory separator character
@@ -897,7 +897,7 @@ int sqlite3_db_cacheflush(sqlite3 *db){
  sqlite3BtreeEnterAll(db);
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
-    if( pBt && sqlite3BtreeIsInTrans(pBt) ){
+    if( pBt && sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE ){
      Pager *pPager = sqlite3BtreePager(pBt);
      rc = sqlite3PagerFlush(pPager);
      if( rc==SQLITE_BUSY ){
@@ -1202,7 +1202,7 @@ static int sqlite3Close(sqlite3 *db, int forceZombie){
  }
  sqlite3_mutex_enter(db->mutex);
  if( db->mTrace & SQLITE_TRACE_CLOSE ){
-    db->xTrace(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
+    db->trace.xV2(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
  }

  /* Force xDisconnect calls on all virtual tables */
@@ -1241,6 +1241,36 @@ static int sqlite3Close(sqlite3 *db, int forceZombie){
  return SQLITE_OK;
 }

+/*
+** Return the transaction state for a single databse, or the maximum
+** transaction state over all attached databases if zSchema is null.
+*/
+int sqlite3_txn_state(sqlite3 *db, const char *zSchema){
+  int iDb, nDb;
+  int iTxn = -1;
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ){
+    (void)SQLITE_MISUSE_BKPT;
+    return -1;
+  }
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  if( zSchema ){
+    nDb = iDb = sqlite3FindDbName(db, zSchema);
+    if( iDb<0 ) nDb--;
+  }else{
+    iDb = 0;
+    nDb = db->nDb-1;
+  }
+  for(; iDb<=nDb; iDb++){
+    Btree *pBt = db->aDb[iDb].pBt;
+    int x = pBt!=0 ? sqlite3BtreeTxnState(pBt) : SQLITE_TXN_NONE;
+    if( x>iTxn ) iTxn = x;
+  }
+  sqlite3_mutex_leave(db->mutex);
+  return iTxn;
+}
+
 /*
 ** Two variations on the public interface for closing a database
 ** connection. The sqlite3_close() version returns SQLITE_BUSY and
@@ -1401,7 +1431,7 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;
    if( p ){
-      if( sqlite3BtreeIsInTrans(p) ){
+      if( sqlite3BtreeTxnState(p)==SQLITE_TXN_WRITE ){
        inTrans = 1;
      }
      sqlite3BtreeRollback(p, tripCode, !schemaChange);
@@ -2091,7 +2121,7 @@ void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pTraceArg;
  db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
-  db->xTrace = (int(*)(u32,void*,void*,void*))xTrace;
+  db->trace.xLegacy = xTrace;
  db->pTraceArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
@@ -2115,7 +2145,7 @@ int sqlite3_trace_v2(
  if( mTrace==0 ) xTrace = 0;
  if( xTrace==0 ) mTrace = 0;
  db->mTrace = mTrace;
-  db->xTrace = xTrace;
+  db->trace.xV2 = xTrace;
  db->pTraceArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
@@ -3822,7 +3852,9 @@ int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
      }
      rc = SQLITE_OK;
    }else{
+      int nSave = db->busyHandler.nBusy;
      rc = sqlite3OsFileControl(fd, op, pArg);
+      db->busyHandler.nBusy = nSave;
    }
    sqlite3BtreeLeave(pBtree);
  }
@@ -4095,7 +4127,7 @@ int sqlite3_test_control(int op, ...){
    ** 2020-07-22:  Disabling EXTRA_SCHEMA_CHECKS also disables the
    ** verification of rootpage numbers when parsing the schema.  This
    ** is useful to make it easier to reach strange internal error states
-    ** during testing.  The EXTRA_SCHEMA_CHECKS settting is always enabled
+    ** during testing.  The EXTRA_SCHEMA_CHECKS setting is always enabled
    ** in production.
    */
    case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
@@ -4205,6 +4237,25 @@ int sqlite3_test_control(int op, ...){
      sqlite3ResultIntReal(pCtx);
      break;
    }
+
+    /*  sqlite3_test_control(SQLITE_TESTCTRL_SEEK_COUNT,
+    **    sqlite3 *db,    // Database connection
+    **    u64 *pnSeek     // Write seek count here
+    **  );
+    **
+    ** This test-control queries the seek-counter on the "main" database
+    ** file.  The seek-counter is written into *pnSeek and is then reset.
+    ** The seek-count is only available if compiled with SQLITE_DEBUG.
+    */
+    case SQLITE_TESTCTRL_SEEK_COUNT: {
+      sqlite3 *db = va_arg(ap, sqlite3*);
+      u64 *pn = va_arg(ap, sqlite3_uint64*);
+      *pn = sqlite3BtreeSeekCount(db->aDb->pBt);
+      (void)db;  /* Silence harmless unused variable warning */
+      break;
+    }
+
+
  }
  va_end(ap);
 #endif /* SQLITE_UNTESTABLE */
@@ -4440,7 +4491,7 @@ int sqlite3_snapshot_get(
    int iDb = sqlite3FindDbName(db, zDb);
    if( iDb==0 || iDb>1 ){
      Btree *pBt = db->aDb[iDb].pBt;
-      if( 0==sqlite3BtreeIsInTrans(pBt) ){
+      if( SQLITE_TXN_WRITE!=sqlite3BtreeTxnState(pBt) ){
        rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
@@ -4476,10 +4527,10 @@ int sqlite3_snapshot_open(
    iDb = sqlite3FindDbName(db, zDb);
    if( iDb==0 || iDb>1 ){
      Btree *pBt = db->aDb[iDb].pBt;
-      if( sqlite3BtreeIsInTrans(pBt)==0 ){
+      if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE ){
        Pager *pPager = sqlite3BtreePager(pBt);
        int bUnlock = 0;
-        if( sqlite3BtreeIsInReadTrans(pBt) ){
+        if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_NONE ){
          if( db->nVdbeActive==0 ){
            rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
            if( rc==SQLITE_OK ){
@@ -4528,7 +4579,7 @@ int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
  iDb = sqlite3FindDbName(db, zDb);
  if( iDb==0 || iDb>1 ){
    Btree *pBt = db->aDb[iDb].pBt;
-    if( 0==sqlite3BtreeIsInReadTrans(pBt) ){
+    if( SQLITE_TXN_NONE==sqlite3BtreeTxnState(pBt) ){
      rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
      if( rc==SQLITE_OK ){
        rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
@@ -474,12 +474,17 @@ void *sqlite3Realloc(void *pOld, u64 nBytes){
  if( nOld==nNew ){
    pNew = pOld;
  }else if( sqlite3GlobalConfig.bMemstat ){
+    sqlite3_int64 nUsed;
    sqlite3_mutex_enter(mem0.mutex);
    sqlite3StatusHighwater(SQLITE_STATUS_MALLOC_SIZE, (int)nBytes);
    nDiff = nNew - nOld;
-    if( nDiff>0 && sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED) >= 
+    if( nDiff>0 && (nUsed = sqlite3StatusValue(SQLITE_STATUS_MEMORY_USED)) >= 
          mem0.alarmThreshold-nDiff ){
      sqlite3MallocAlarm(nDiff);
+      if( mem0.hardLimit>0 && nUsed >= mem0.hardLimit - nDiff ){
+        sqlite3_mutex_leave(mem0.mutex);
+        return 0;
+      }
    }
    pNew = sqlite3GlobalConfig.m.xRealloc(pOld, nNew);
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
@@ -786,12 +791,15 @@ void sqlite3OomClear(sqlite3 *db){
 }

 /*
-** Take actions at the end of an API call to indicate an OOM error
+** Take actions at the end of an API call to deal with error codes.
 */
-static SQLITE_NOINLINE int apiOomError(sqlite3 *db){
-  sqlite3OomClear(db);
-  sqlite3Error(db, SQLITE_NOMEM);
-  return SQLITE_NOMEM_BKPT;
+static SQLITE_NOINLINE int apiHandleError(sqlite3 *db, int rc){
+  if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
+    sqlite3OomClear(db);
+    sqlite3Error(db, SQLITE_NOMEM);
+    return SQLITE_NOMEM_BKPT;
+  }
+  return rc & db->errMask;
 }

 /*
@@ -813,8 +821,8 @@ int sqlite3ApiExit(sqlite3* db, int rc){
  */
  assert( db!=0 );
  assert( sqlite3_mutex_held(db->mutex) );
-  if( db->mallocFailed || rc==SQLITE_IOERR_NOMEM ){
-    return apiOomError(db);
+  if( db->mallocFailed || rc ){
+    return apiHandleError(db, rc);
  }
  return rc & db->errMask;
 }
@@ -126,11 +126,14 @@ static const sqlite3_io_methods memdb_io_methods = {
 ** Close an memdb-file.
 **
 ** The pData pointer is owned by the application, so there is nothing
-** to free.
+** to free.  Unless the SQLITE_DESERIALIZE_FREEONCLOSE flag is set,
+** in which case we own the pData pointer and need to free it.
 */
 static int memdbClose(sqlite3_file *pFile){
  MemFile *p = (MemFile *)pFile;
-  if( p->mFlags & SQLITE_DESERIALIZE_FREEONCLOSE ) sqlite3_free(p->aData);
+  if( p->mFlags & SQLITE_DESERIALIZE_FREEONCLOSE ){
+    sqlite3_free(p->aData);
+  }
  return SQLITE_OK;
 }

@@ -573,8 +576,12 @@ int sqlite3_deserialize(
    goto end_deserialize;
  }    
  zSql = sqlite3_mprintf("ATTACH x AS %Q", zSchema);
-  rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
-  sqlite3_free(zSql);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
+    sqlite3_free(zSql);
+  }
  if( rc ) goto end_deserialize;
  db->init.iDb = (u8)iDb;
  db->init.reopenMemdb = 1;
@@ -589,6 +596,7 @@ int sqlite3_deserialize(
    rc = SQLITE_ERROR;
  }else{
    p->aData = pData;
+    pData = 0;
    p->sz = szDb;
    p->szAlloc = szBuf;
    p->szMax = szBuf;
@@ -601,6 +609,9 @@ int sqlite3_deserialize(

 end_deserialize:
  sqlite3_finalize(pStmt);
+  if( pData && (mFlags & SQLITE_DESERIALIZE_FREEONCLOSE)!=0 ){
+    sqlite3_free(pData);
+  }
  sqlite3_mutex_leave(db->mutex);
  return rc;
 }
@@ -122,7 +122,8 @@
 # if defined(__APPLE__) && ((__MAC_OS_X_VERSION_MIN_REQUIRED > 1050) || \
                            (__IPHONE_OS_VERSION_MIN_REQUIRED > 2000))
 #    if (!defined(TARGET_OS_EMBEDDED) || (TARGET_OS_EMBEDDED==0)) \
-         && (!defined(TARGET_IPHONE_SIMULATOR) || (TARGET_IPHONE_SIMULATOR==0))
+        && (!defined(TARGET_IPHONE_SIMULATOR) || (TARGET_IPHONE_SIMULATOR==0))\
+        && (!defined(TARGET_OS_MACCATALYST) || (TARGET_OS_MACCATALYST==0))
 #      undef HAVE_GETHOSTUUID
 #      define HAVE_GETHOSTUUID 1
 #    else
@@ -1544,6 +1545,9 @@ static int unixCheckReservedLock(sqlite3_file *id, int *pResOut){
  return rc;
 }

+/* Forward declaration*/
+static int unixSleep(sqlite3_vfs*,int);
+
 /*
 ** Set a posix-advisory-lock.
 **
@@ -1573,7 +1577,7 @@ static int osSetPosixAdvisoryLock(
    ** generic posix, however, there is no such API.  So we simply try the
    ** lock once every millisecond until either the timeout expires, or until
    ** the lock is obtained. */
-    usleep(1000);
+    unixSleep(0,1000);
    rc = osFcntl(h,F_SETLK,pLock);
    tm--;
  }
@@ -2144,6 +2148,7 @@ static int unixClose(sqlite3_file *id){
  }
  sqlite3_mutex_leave(pInode->pLockMutex);
  releaseInodeInfo(pFile);
+  assert( pFile->pShm==0 );
  rc = closeUnixFile(id);
  unixLeaveMutex();
  return rc;
@@ -3370,7 +3375,24 @@ static int unixRead(
  if( got==amt ){
    return SQLITE_OK;
  }else if( got<0 ){
-    /* lastErrno set by seekAndRead */
+    /* pFile->lastErrno has been set by seekAndRead().
+    ** Usually we return SQLITE_IOERR_READ here, though for some
+    ** kinds of errors we return SQLITE_IOERR_CORRUPTFS.  The
+    ** SQLITE_IOERR_CORRUPTFS will be converted into SQLITE_CORRUPT
+    ** prior to returning to the application by the sqlite3ApiExit()
+    ** routine.
+    */
+    switch( pFile->lastErrno ){
+      case ERANGE:
+      case EIO:
+#ifdef ENXIO
+      case ENXIO:
+#endif
+#ifdef EDEVERR
+      case EDEVERR:
+#endif
+        return SQLITE_IOERR_CORRUPTFS;
+    }
    return SQLITE_IOERR_READ;
  }else{
    storeLastErrno(pFile, 0);   /* not a system error */
@@ -4254,6 +4276,7 @@ struct unixShmNode {
  char **apRegion;           /* Array of mapped shared-memory regions */
  int nRef;                  /* Number of unixShm objects pointing to this */
  unixShm *pFirst;           /* All unixShm objects pointing to this */
+  int aLock[SQLITE_SHM_NLOCK];  /* # shared locks on slot, -1==excl lock */
 #ifdef SQLITE_DEBUG
  u8 exclMask;               /* Mask of exclusive locks held */
  u8 sharedMask;             /* Mask of shared locks held */
@@ -4794,6 +4817,38 @@ shmpage_out:
  return rc;
 }

+/*
+** Check that the pShmNode->aLock[] array comports with the locking bitmasks
+** held by each client. Return true if it does, or false otherwise. This
+** is to be used in an assert(). e.g.
+**
+**     assert( assertLockingArrayOk(pShmNode) );
+*/
+#ifdef SQLITE_DEBUG
+static int assertLockingArrayOk(unixShmNode *pShmNode){
+  unixShm *pX;
+  int aLock[SQLITE_SHM_NLOCK];
+  assert( sqlite3_mutex_held(pShmNode->pShmMutex) );
+
+  memset(aLock, 0, sizeof(aLock));
+  for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
+    int i;
+    for(i=0; i<SQLITE_SHM_NLOCK; i++){
+      if( pX->exclMask & (1<<i) ){
+        assert( aLock[i]==0 );
+        aLock[i] = -1;
+      }else if( pX->sharedMask & (1<<i) ){
+        assert( aLock[i]>=0 );
+        aLock[i]++;
+      }
+    }
+  }
+
+  assert( 0==memcmp(pShmNode->aLock, aLock, sizeof(aLock)) );
+  return (memcmp(pShmNode->aLock, aLock, sizeof(aLock))==0);
+}
+#endif
+
 /*
 ** Change the lock state for a shared-memory segment.
 **
@@ -4810,10 +4865,10 @@ static int unixShmLock(
 ){
  unixFile *pDbFd = (unixFile*)fd;      /* Connection holding shared memory */
  unixShm *p = pDbFd->pShm;             /* The shared memory being locked */
-  unixShm *pX;                          /* For looping over all siblings */
  unixShmNode *pShmNode = p->pShmNode;  /* The underlying file iNode */
  int rc = SQLITE_OK;                   /* Result code */
  u16 mask;                             /* Mask of locks to take or release */
+  int *aLock = pShmNode->aLock;

  assert( pShmNode==pDbFd->pInode->pShmNode );
  assert( pShmNode->pInode==pDbFd->pInode );
@@ -4852,78 +4907,76 @@ static int unixShmLock(
  mask = (1<<(ofst+n)) - (1<<ofst);
  assert( n>1 || mask==(1<<ofst) );
  sqlite3_mutex_enter(pShmNode->pShmMutex);
+  assert( assertLockingArrayOk(pShmNode) );
  if( flags & SQLITE_SHM_UNLOCK ){
-    u16 allMask = 0; /* Mask of locks held by siblings */
+    if( (p->exclMask|p->sharedMask) & mask ){
+      int ii;
+      int bUnlock = 1;

-    /* See if any siblings hold this same lock */
-    for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
-      if( pX==p ) continue;
-      assert( (pX->exclMask & (p->exclMask|p->sharedMask))==0 );
-      allMask |= pX->sharedMask;
+      for(ii=ofst; ii<ofst+n; ii++){
+        if( aLock[ii]>((p->sharedMask & (1<<ii)) ? 1 : 0) ){
+          bUnlock = 0;
+        }
+      }
+
+      if( bUnlock ){
+        rc = unixShmSystemLock(pDbFd, F_UNLCK, ofst+UNIX_SHM_BASE, n);
+        if( rc==SQLITE_OK ){
+          memset(&aLock[ofst], 0, sizeof(int)*n);
+        }
+      }else if( ALWAYS(p->sharedMask & (1<<ofst)) ){
+        assert( n==1 && aLock[ofst]>1 );
+        aLock[ofst]--;
+      }
+
+      /* Undo the local locks */
+      if( rc==SQLITE_OK ){
+        p->exclMask &= ~mask;
+        p->sharedMask &= ~mask;
+      } 
    }
-
-    /* Unlock the system-level locks */
-    if( (mask & allMask)==0 ){
-      rc = unixShmSystemLock(pDbFd, F_UNLCK, ofst+UNIX_SHM_BASE, n);
-    }else{
-      rc = SQLITE_OK;
-    }
-
-    /* Undo the local locks */
-    if( rc==SQLITE_OK ){
-      p->exclMask &= ~mask;
-      p->sharedMask &= ~mask;
-    } 
  }else if( flags & SQLITE_SHM_SHARED ){
-    u16 allShared = 0;  /* Union of locks held by connections other than "p" */
-
-    /* Find out which shared locks are already held by sibling connections.
-    ** If any sibling already holds an exclusive lock, go ahead and return
-    ** SQLITE_BUSY.
-    */
-    for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
-      if( (pX->exclMask & mask)!=0 ){
+    assert( n==1 );
+    assert( (p->exclMask & (1<<ofst))==0 );
+    if( (p->sharedMask & mask)==0 ){
+      if( aLock[ofst]<0 ){
        rc = SQLITE_BUSY;
-        break;
-      }
-      allShared |= pX->sharedMask;
-    }
-
-    /* Get shared locks at the system level, if necessary */
-    if( rc==SQLITE_OK ){
-      if( (allShared & mask)==0 ){
+      }else if( aLock[ofst]==0 ){
        rc = unixShmSystemLock(pDbFd, F_RDLCK, ofst+UNIX_SHM_BASE, n);
-      }else{
-        rc = SQLITE_OK;
      }
-    }

-    /* Get the local shared locks */
-    if( rc==SQLITE_OK ){
-      p->sharedMask |= mask;
+      /* Get the local shared locks */
+      if( rc==SQLITE_OK ){
+        p->sharedMask |= mask;
+        aLock[ofst]++;
+      }
    }
  }else{
    /* Make sure no sibling connections hold locks that will block this
-    ** lock.  If any do, return SQLITE_BUSY right away.
-    */
-    for(pX=pShmNode->pFirst; pX; pX=pX->pNext){
-      if( (pX->exclMask & mask)!=0 || (pX->sharedMask & mask)!=0 ){
+    ** lock.  If any do, return SQLITE_BUSY right away.  */
+    int ii;
+    for(ii=ofst; ii<ofst+n; ii++){
+      assert( (p->sharedMask & mask)==0 );
+      if( ALWAYS((p->exclMask & (1<<ii))==0) && aLock[ii] ){
        rc = SQLITE_BUSY;
        break;
      }
    }
-  
-    /* Get the exclusive locks at the system level.  Then if successful
-    ** also mark the local connection as being locked.
-    */
+
+    /* Get the exclusive locks at the system level. Then if successful
+    ** also update the in-memory values. */
    if( rc==SQLITE_OK ){
      rc = unixShmSystemLock(pDbFd, F_WRLCK, ofst+UNIX_SHM_BASE, n);
      if( rc==SQLITE_OK ){
        assert( (p->sharedMask & mask)==0 );
        p->exclMask |= mask;
+        for(ii=ofst; ii<ofst+n; ii++){
+          aLock[ii] = -1;
+        }
      }
    }
  }
+  assert( assertLockingArrayOk(pShmNode) );
  sqlite3_mutex_leave(pShmNode->pShmMutex);
  OSTRACE(("SHM-LOCK shmid-%d, pid-%d got %03x,%03x\n",
           p->id, osGetpid(0), p->sharedMask, p->exclMask));
@@ -6300,7 +6353,26 @@ static int unixAccess(
 }

 /*
+** If the last component of the pathname in z[0]..z[j-1] is something
+** other than ".." then back it out and return true.  If the last
+** component is empty or if it is ".." then return false.
+*/
+static int unixBackupDir(const char *z, int *pJ){
+  int j = *pJ;
+  int i;
+  if( j<=0 ) return 0;
+  for(i=j-1; ALWAYS(i>0) && z[i-1]!='/'; i--){}
+  if( z[i]=='.' && i==j-2 && z[i+1]=='.' ) return 0;
+  *pJ = i-1;
+  return 1;
+}
+
+/*
+** Convert a relative pathname into a full pathname.  Also
+** simplify the pathname as follows:
 **
+**    Remove all instances of /./
+**    Remove all isntances of /X/../ for any X
 */
 static int mkFullPathname(
  const char *zPath,              /* Input path */
@@ -6309,6 +6381,7 @@ static int mkFullPathname(
 ){
  int nPath = sqlite3Strlen30(zPath);
  int iOff = 0;
+  int i, j;
  if( zPath[0]!='/' ){
    if( osGetcwd(zOut, nOut-2)==0 ){
      return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
@@ -6323,6 +6396,41 @@ static int mkFullPathname(
    return SQLITE_CANTOPEN_BKPT;
  }
  sqlite3_snprintf(nOut-iOff, &zOut[iOff], "%s", zPath);
+
+  /* Remove duplicate '/' characters.  Except, two // at the beginning
+  ** of a pathname is allowed since this is important on windows. */
+  for(i=j=1; zOut[i]; i++){
+    zOut[j++] = zOut[i];
+    while( zOut[i]=='/' && zOut[i+1]=='/' ) i++;
+  }
+  zOut[j] = 0;
+
+  assert( zOut[0]=='/' );
+  for(i=j=0; zOut[i]; i++){
+    if( zOut[i]=='/' ){
+      /* Skip over internal "/." directory components */
+      if( zOut[i+1]=='.' && zOut[i+2]=='/' ){
+        i += 1;
+        continue;
+      }
+
+      /* If this is a "/.." directory component then back out the
+      ** previous term of the directory if it is something other than "..".
+      */
+      if( zOut[i+1]=='.'
+       && zOut[i+2]=='.'
+       && zOut[i+3]=='/'
+       && unixBackupDir(zOut, &j)
+      ){
+        i += 2;
+        continue;
+      }
+    }
+    if( ALWAYS(j>=0) ) zOut[j] = zOut[i];
+    j++;
+  }
+  if( NEVER(j==0) ) zOut[j++] = '/';
+  zOut[j] = 0;
  return SQLITE_OK;
 }

@@ -6543,7 +6651,8 @@ static int unixSleep(sqlite3_vfs *NotUsed, int microseconds){
  UNUSED_PARAMETER(NotUsed);
  return microseconds;
 #elif defined(HAVE_USLEEP) && HAVE_USLEEP
-  usleep(microseconds);
+  if( microseconds>=1000000 ) sleep(microseconds/1000000);
+  if( microseconds%1000000 ) usleep(microseconds%1000000);
  UNUSED_PARAMETER(NotUsed);
  return microseconds;
 #else
@@ -7116,7 +7225,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
      
      if( nTries==1 ){
        conchModTime = buf.st_mtimespec;
-        usleep(500000); /* wait 0.5 sec and try the lock again*/
+        unixSleep(0,500000); /* wait 0.5 sec and try the lock again*/
        continue;  
      }

@@ -7142,7 +7251,7 @@ static int proxyConchLock(unixFile *pFile, uuid_t myHostID, int lockType){
          /* don't break the lock on short read or a version mismatch */
          return SQLITE_BUSY;
        }
-        usleep(10000000); /* wait 10 sec and try the lock again */
+        unixSleep(0,10000000); /* wait 10 sec and try the lock again */
        continue; 
      }
      
@@ -5126,7 +5126,11 @@ static int winOpen(
    dwCreationDisposition = OPEN_EXISTING;
  }

-  dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
+  if( 0==sqlite3_uri_boolean(zName, "exclusive", 0) ){
+    dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
+  }else{
+    dwShareMode = 0;
+  }

  if( isDelete ){
 #if SQLITE_OS_WINCE
@@ -2486,18 +2486,20 @@ static int pager_delsuper(Pager *pPager, const char *zSuper){
  i64 nSuperJournal;        /* Size of super-journal file */
  char *zJournal;           /* Pointer to one journal within MJ file */
  char *zSuperPtr;          /* Space to hold super-journal filename */
+  char *zFree = 0;          /* Free this buffer */
  int nSuperPtr;            /* Amount of space allocated to zSuperPtr[] */

  /* Allocate space for both the pJournal and pSuper file descriptors.
  ** If successful, open the super-journal file for reading.
  */
  pSuper = (sqlite3_file *)sqlite3MallocZero(pVfs->szOsFile * 2);
-  pJournal = (sqlite3_file *)(((u8 *)pSuper) + pVfs->szOsFile);
  if( !pSuper ){
    rc = SQLITE_NOMEM_BKPT;
+    pJournal = 0;
  }else{
    const int flags = (SQLITE_OPEN_READONLY|SQLITE_OPEN_SUPER_JOURNAL);
    rc = sqlite3OsOpen(pVfs, zSuper, pSuper, flags, 0);
+    pJournal = (sqlite3_file *)(((u8 *)pSuper) + pVfs->szOsFile);
  }
  if( rc!=SQLITE_OK ) goto delsuper_out;

@@ -2509,11 +2511,13 @@ static int pager_delsuper(Pager *pPager, const char *zSuper){
  rc = sqlite3OsFileSize(pSuper, &nSuperJournal);
  if( rc!=SQLITE_OK ) goto delsuper_out;
  nSuperPtr = pVfs->mxPathname+1;
-  zSuperJournal = sqlite3Malloc(nSuperJournal + nSuperPtr + 2);
-  if( !zSuperJournal ){
+  zFree = sqlite3Malloc(4 + nSuperJournal + nSuperPtr + 2);
+  if( !zFree ){
    rc = SQLITE_NOMEM_BKPT;
    goto delsuper_out;
  }
+  zFree[0] = zFree[1] = zFree[2] = zFree[3] = 0;
+  zSuperJournal = &zFree[4];
  zSuperPtr = &zSuperJournal[nSuperJournal+2];
  rc = sqlite3OsRead(pSuper, zSuperJournal, (int)nSuperJournal, 0);
  if( rc!=SQLITE_OK ) goto delsuper_out;
@@ -2561,7 +2565,7 @@ static int pager_delsuper(Pager *pPager, const char *zSuper){
  rc = sqlite3OsDelete(pVfs, zSuper, 0);

 delsuper_out:
-  sqlite3_free(zSuperJournal);
+  sqlite3_free(zFree);
  if( pSuper ){
    sqlite3OsClose(pSuper);
    assert( !isOpen(pJournal) );
@@ -2899,7 +2903,11 @@ end_playback:
  pPager->changeCountDone = pPager->tempFile;

  if( rc==SQLITE_OK ){
-    zSuper = pPager->pTmpSpace;
+    /* Leave 4 bytes of space before the super-journal filename in memory.
+    ** This is because it may end up being passed to sqlite3OsOpen(), in
+    ** which case it requires 4 0x00 bytes in memory immediately before
+    ** the filename. */
+    zSuper = &pPager->pTmpSpace[4];
    rc = readSuperJournal(pPager->jfd, zSuper, pPager->pVfs->mxPathname+1);
    testcase( rc!=SQLITE_OK );
  }
@@ -2916,6 +2924,8 @@ end_playback:
    /* If there was a super-journal and this routine will return success,
    ** see if it is possible to delete the super-journal.
    */
+    assert( zSuper==&pPager->pTmpSpace[4] );
+    memset(&zSuper[-4], 0, 4);
    rc = pager_delsuper(pPager, zSuper);
    testcase( rc!=SQLITE_OK );
  }
@@ -1,5 +1,6 @@
+%include {
 /*
-** 2001 September 15
+** 2001-09-15
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
@@ -9,11 +10,16 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** This file contains SQLite's grammar for SQL.  Process this file
-** using the lemon parser generator to generate C code that runs
-** the parser.  Lemon will also generate a header file containing
-** numeric codes for all of the tokens.
+** This file contains SQLite's SQL parser.
+**
+** The canonical source code to this file ("parse.y") is a Lemon grammar 
+** file that specifies the input grammar and actions to take while parsing.
+** That input file is processed by Lemon to generate a C-language 
+** implementation of a parser for the given grammer.  You might be reading
+** this comment as part of the translated C-code.  Edits should be made
+** to the original parse.y sources.
 */
+}

 // All token codes are small integers with #defines that begin with "TK_"
 %token_prefix TK_
@@ -366,7 +372,7 @@ ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
                                 {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
 ccons ::= UNIQUE onconf(R).      {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0,0,
                                   SQLITE_IDXTYPE_UNIQUE);}
-ccons ::= CHECK LP expr(X) RP.   {sqlite3AddCheckConstraint(pParse,X);}
+ccons ::= CHECK LP(A) expr(X) RP(B).  {sqlite3AddCheckConstraint(pParse,X,A.z,B.z);}
 ccons ::= REFERENCES nm(T) eidlist_opt(TA) refargs(R).
                                 {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
 ccons ::= defer_subclause(D).    {sqlite3DeferForeignKey(pParse,D);}
@@ -420,8 +426,8 @@ tcons ::= PRIMARY KEY LP sortlist(X) autoinc(I) RP onconf(R).
 tcons ::= UNIQUE LP sortlist(X) RP onconf(R).
                                 {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0,0,0,
                                       SQLITE_IDXTYPE_UNIQUE);}
-tcons ::= CHECK LP expr(E) RP onconf.
-                                 {sqlite3AddCheckConstraint(pParse,E);}
+tcons ::= CHECK LP(A) expr(E) RP(B) onconf.
+                                 {sqlite3AddCheckConstraint(pParse,E,A.z,B.z);}
 tcons ::= FOREIGN KEY LP eidlist(FA) RP
          REFERENCES nm(T) eidlist_opt(TA) refargs(R) defer_subclause_opt(D). {
    sqlite3CreateForeignKey(pParse, FA, &T, TA, R);
@@ -131,7 +131,9 @@ static int getTempStore(const char *z){
 static int invalidateTempStorage(Parse *pParse){
  sqlite3 *db = pParse->db;
  if( db->aDb[1].pBt!=0 ){
-    if( !db->autoCommit || sqlite3BtreeIsInReadTrans(db->aDb[1].pBt) ){
+    if( !db->autoCommit
+     || sqlite3BtreeTxnState(db->aDb[1].pBt)!=SQLITE_TXN_NONE
+    ){
      sqlite3ErrorMsg(pParse, "temporary storage cannot be changed "
        "from within a transaction");
      return SQLITE_ERROR;
@@ -1451,7 +1453,7 @@ void sqlite3Pragma(
        aiCols = 0;
        if( pParent ){
          x = sqlite3FkLocateIndex(pParse, pParent, pFK, &pIdx, &aiCols);
-          assert( x==0 );
+          assert( x==0 || db->mallocFailed );
        }
        addrOk = sqlite3VdbeMakeLabel(pParse);

@@ -1476,7 +1478,7 @@ void sqlite3Pragma(
          int jmp = sqlite3VdbeCurrentAddr(v)+2;
          sqlite3VdbeAddOp3(v, OP_SeekRowid, i, jmp, regRow); VdbeCoverage(v);
          sqlite3VdbeGoto(v, addrOk);
-          assert( pFK->nCol==1 );
+          assert( pFK->nCol==1 || db->mallocFailed );
        }

        /* Generate code to report an FK violation to the caller. */
@@ -240,7 +240,7 @@ int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg, u32 mFlags){
  ** on the b-tree database, open one now. If a transaction is opened, it 
  ** will be closed before this function returns.  */
  sqlite3BtreeEnter(pDb->pBt);
-  if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){
+  if( sqlite3BtreeTxnState(pDb->pBt)==SQLITE_TXN_NONE ){
    rc = sqlite3BtreeBeginTrans(pDb->pBt, 0, 0);
    if( rc!=SQLITE_OK ){
      sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));
@@ -483,7 +483,7 @@ static void schemaIsValid(Parse *pParse){
    /* If there is not already a read-only (or read-write) transaction opened
    ** on the b-tree database, open one now. If a transaction is opened, it 
    ** will be closed immediately after reading the meta-value. */
-    if( !sqlite3BtreeIsInReadTrans(pBt) ){
+    if( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_NONE ){
      rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
      if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
        sqlite3OomFault(db);
@@ -746,6 +746,7 @@ static int sqlite3LockAndPrepare(
  sqlite3BtreeLeaveAll(db);
  rc = sqlite3ApiExit(db, rc);
  assert( (rc&db->errMask)==rc );
+  db->busyHandler.nBusy = 0;
  sqlite3_mutex_leave(db->mutex);
  return rc;
 }
@@ -407,11 +407,11 @@ void sqlite3_str_vappendf(
      case etPOINTER:
        flag_long = sizeof(char*)==sizeof(i64) ? 2 :
                     sizeof(char*)==sizeof(long int) ? 1 : 0;
-        /* Fall through into the next case */
+        /* no break */ deliberate_fall_through
      case etORDINAL:
      case etRADIX:      
        cThousand = 0;
-        /* Fall through into the next case */
+        /* no break */ deliberate_fall_through
      case etDECIMAL:
        if( infop->flags & FLAG_SIGNED ){
          i64 v;
@@ -427,11 +427,10 @@ void sqlite3_str_vappendf(
            v = va_arg(ap,int);
          }
          if( v<0 ){
-            if( v==SMALLEST_INT64 ){
-              longvalue = ((u64)1)<<63;
-            }else{
-              longvalue = -v;
-            }
+            testcase( v==SMALLEST_INT64 );
+            testcase( v==(-1) );
+            longvalue = ~v;
+            longvalue++;
            prefix = '-';
          }else{
            longvalue = v;
@@ -1075,7 +1075,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
      assert( !ExprHasProperty(pExpr, EP_Reduced) );
      /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE",
      ** and "x IS NOT FALSE". */
-      if( pRight && pRight->op==TK_ID ){
+      if( pRight && (pRight->op==TK_ID || pRight->op==TK_TRUEFALSE) ){
        int rc = resolveExprStep(pWalker, pRight);
        if( rc==WRC_Abort ) return WRC_Abort;
        if( pRight->op==TK_TRUEFALSE ){
@@ -1084,7 +1084,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
          return WRC_Continue;
        }
      }
-      /* Fall thru */
+      /* no break */ deliberate_fall_through
    }
    case TK_BETWEEN:
    case TK_EQ:
@@ -1284,6 +1284,7 @@ static int resolveCompoundOrderBy(
      Expr *pE, *pDup;
      if( pItem->done ) continue;
      pE = sqlite3ExprSkipCollateAndLikely(pItem->pExpr);
+      if( NEVER(pE==0) ) continue;
      if( sqlite3ExprIsInteger(pE, &iCol) ){
        if( iCol<=0 || iCol>pEList->nExpr ){
          resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr);
@@ -1463,6 +1464,7 @@ static int resolveOrderGroupBy(
  for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
    Expr *pE = pItem->pExpr;
    Expr *pE2 = sqlite3ExprSkipCollateAndLikely(pE);
+    if( NEVER(pE2==0) ) continue;
    if( zType[0]!='G' ){
      iCol = resolveAsName(pParse, pSelect->pEList, pE2);
      if( iCol>0 ){
@@ -1972,6 +1972,7 @@ int sqlite3ColumnsFromExprList(
  char *zName;                /* Column name */
  int nName;                  /* Size of name in zName[] */
  Hash ht;                    /* Hash table of column names */
+  Table *pTab;

  sqlite3HashInit(&ht);
  if( pEList ){
@@ -1994,15 +1995,13 @@ int sqlite3ColumnsFromExprList(
      /* If the column contains an "AS <name>" phrase, use <name> as the name */
    }else{
      Expr *pColExpr = sqlite3ExprSkipCollateAndLikely(pEList->a[i].pExpr);
-      while( pColExpr->op==TK_DOT ){
+      while( ALWAYS(pColExpr!=0) && pColExpr->op==TK_DOT ){
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
-      if( pColExpr->op==TK_COLUMN ){
+      if( pColExpr->op==TK_COLUMN && (pTab = pColExpr->y.pTab)!=0 ){
        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
-        Table *pTab = pColExpr->y.pTab;
-        assert( pTab!=0 );
        if( iCol<0 ) iCol = pTab->iPKey;
        zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
      }else if( pColExpr->op==TK_ID ){
@@ -2340,6 +2339,7 @@ static void generateWithRecursiveQuery(
  int nCol = p->pEList->nExpr;  /* Number of columns in the recursive table */
  Vdbe *v = pParse->pVdbe;      /* The prepared statement under construction */
  Select *pSetup = p->pPrior;   /* The setup query */
+  Select *pFirstRec;            /* Left-most recursive term */
  int addrTop;                  /* Top of the loop */
  int addrCont, addrBreak;      /* CONTINUE and BREAK addresses */
  int iCurrent = 0;             /* The Current table */
@@ -2415,7 +2415,25 @@ static void generateWithRecursiveQuery(
  /* Detach the ORDER BY clause from the compound SELECT */
  p->pOrderBy = 0;

+  /* Figure out how many elements of the compound SELECT are part of the
+  ** recursive query.  Make sure no recursive elements use aggregate
+  ** functions.  Mark the recursive elements as UNION ALL even if they
+  ** are really UNION because the distinctness will be enforced by the
+  ** iDistinct table.  pFirstRec is left pointing to the left-most
+  ** recursive term of the CTE.
+  */
+  pFirstRec = p;
+  for(pFirstRec=p; ALWAYS(pFirstRec!=0); pFirstRec=pFirstRec->pPrior){
+    if( pFirstRec->selFlags & SF_Aggregate ){
+      sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
+      goto end_of_recursive_query;
+    }
+    pFirstRec->op = TK_ALL;
+    if( (pFirstRec->pPrior->selFlags & SF_Recursive)==0 ) break;
+  }
+
  /* Store the results of the setup-query in Queue. */
+  pSetup = pFirstRec->pPrior;
  pSetup->pNext = 0;
  ExplainQueryPlan((pParse, 1, "SETUP"));
  rc = sqlite3Select(pParse, pSetup, &destQueue);
@@ -2448,15 +2466,11 @@ static void generateWithRecursiveQuery(
  /* Execute the recursive SELECT taking the single row in Current as
  ** the value for the recursive-table. Store the results in the Queue.
  */
-  if( p->selFlags & SF_Aggregate ){
-    sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported");
-  }else{
-    p->pPrior = 0;
-    ExplainQueryPlan((pParse, 1, "RECURSIVE STEP"));
-    sqlite3Select(pParse, p, &destQueue);
-    assert( p->pPrior==0 );
-    p->pPrior = pSetup;
-  }
+  pFirstRec->pPrior = 0;
+  ExplainQueryPlan((pParse, 1, "RECURSIVE STEP"));
+  sqlite3Select(pParse, p, &destQueue);
+  assert( pFirstRec->pPrior==0 );
+  pFirstRec->pPrior = pSetup;

  /* Keep running the loop until the Queue is empty */
  sqlite3VdbeGoto(v, addrTop);
@@ -2525,6 +2539,16 @@ static int multiSelectValues(
  return rc;
 }

+/*
+** Return true if the SELECT statement which is known to be the recursive
+** part of a recursive CTE still has its anchor terms attached.  If the
+** anchor terms have already been removed, then return false.
+*/
+static int hasAnchor(Select *p){
+  while( p && (p->selFlags & SF_Recursive)!=0 ){ p = p->pPrior; }
+  return p!=0;
+}
+
 /*
 ** This routine is called to process a compound query form from
 ** two or more separate queries using UNION, UNION ALL, EXCEPT, or
@@ -2610,7 +2634,7 @@ static int multiSelect(
  assert( p->pEList->nExpr==pPrior->pEList->nExpr );

 #ifndef SQLITE_OMIT_CTE
-  if( p->selFlags & SF_Recursive ){
+  if( (p->selFlags & SF_Recursive)!=0 && hasAnchor(p) ){
    generateWithRecursiveQuery(pParse, p, &dest);
  }else
 #endif
@@ -2701,6 +2725,7 @@ static int multiSelect(
          findRightmost(p)->selFlags |= SF_UsesEphemeral;
          assert( p->pEList );
        }
+          
  
        /* Code the SELECT statements to our left
        */
@@ -3506,7 +3531,7 @@ static Expr *substExpr(
          ifNullRow.op = TK_IF_NULL_ROW;
          ifNullRow.pLeft = pCopy;
          ifNullRow.iTable = pSubst->iNewTable;
-          ifNullRow.flags = EP_Skip;
+          ifNullRow.flags = EP_IfNullRow;
          pCopy = &ifNullRow;
        }
        testcase( ExprHasProperty(pCopy, EP_Subquery) );
@@ -3515,8 +3540,7 @@ static Expr *substExpr(
          ExprSetProperty(pNew, EP_CanBeNull);
        }
        if( pNew && ExprHasProperty(pExpr,EP_FromJoin) ){
-          pNew->iRightJoinTable = pExpr->iRightJoinTable;
-          ExprSetProperty(pNew, EP_FromJoin);
+          sqlite3SetJoinExpr(pNew, pExpr->iRightJoinTable);
        }
        sqlite3ExprDelete(db, pExpr);
        pExpr = pNew;
@@ -4186,7 +4210,7 @@ static int flattenSubquery(
  sqlite3SelectDelete(db, pSub1);

 #if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x100 ){
+  if( sqlite3_unsupported_selecttrace & 0x100 ){
    SELECTTRACE(0x100,pParse,p,("After flattening:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
@@ -4795,8 +4819,10 @@ static int withExpand(
    ExprList *pEList;
    Select *pSel;
    Select *pLeft;                /* Left-most SELECT statement */
+    Select *pRecTerm;             /* Left-most recursive term */
    int bMayRecursive;            /* True if compound joined by UNION [ALL] */
    With *pSavedWith;             /* Initial value of pParse->pWith */
+    int iRecTab = -1;             /* Cursor for recursive table */

    /* If pCte->zCteErr is non-NULL at this point, then this is an illegal
    ** recursive reference to CTE pCte. Leave an error in pParse and return
@@ -4821,44 +4847,48 @@ static int withExpand(
    assert( pFrom->pSelect );

    /* Check if this is a recursive CTE. */
-    pSel = pFrom->pSelect;
+    pRecTerm = pSel = pFrom->pSelect;
    bMayRecursive = ( pSel->op==TK_ALL || pSel->op==TK_UNION );
-    if( bMayRecursive ){
+    while( bMayRecursive && pRecTerm->op==pSel->op ){
      int i;
-      SrcList *pSrc = pFrom->pSelect->pSrc;
+      SrcList *pSrc = pRecTerm->pSrc;
+      assert( pRecTerm->pPrior!=0 );
      for(i=0; i<pSrc->nSrc; i++){
        struct SrcList_item *pItem = &pSrc->a[i];
        if( pItem->zDatabase==0 
         && pItem->zName!=0 
         && 0==sqlite3StrICmp(pItem->zName, pCte->zName)
-          ){
+        ){
          pItem->pTab = pTab;
-          pItem->fg.isRecursive = 1;
          pTab->nTabRef++;
-          pSel->selFlags |= SF_Recursive;
+          pItem->fg.isRecursive = 1;
+          if( pRecTerm->selFlags & SF_Recursive ){
+            sqlite3ErrorMsg(pParse,
+               "multiple references to recursive table: %s", pCte->zName
+            );
+            return SQLITE_ERROR;
+          }
+          pRecTerm->selFlags |= SF_Recursive;
+          if( iRecTab<0 ) iRecTab = pParse->nTab++;
+          pItem->iCursor = iRecTab;
        }
      }
+      if( (pRecTerm->selFlags & SF_Recursive)==0 ) break;
+      pRecTerm = pRecTerm->pPrior;
    }

-    /* Only one recursive reference is permitted. */ 
-    if( pTab->nTabRef>2 ){
-      sqlite3ErrorMsg(
-          pParse, "multiple references to recursive table: %s", pCte->zName
-      );
-      return SQLITE_ERROR;
-    }
-    assert( pTab->nTabRef==1 || 
-            ((pSel->selFlags&SF_Recursive) && pTab->nTabRef==2 ));
-
    pCte->zCteErr = "circular reference: %s";
    pSavedWith = pParse->pWith;
    pParse->pWith = pWith;
-    if( bMayRecursive ){
-      Select *pPrior = pSel->pPrior;
-      assert( pPrior->pWith==0 );
-      pPrior->pWith = pSel->pWith;
-      sqlite3WalkSelect(pWalker, pPrior);
-      pPrior->pWith = 0;
+    if( pSel->selFlags & SF_Recursive ){
+      assert( pRecTerm!=0 );
+      assert( (pRecTerm->selFlags & SF_Recursive)==0 );
+      assert( pRecTerm->pNext!=0 );
+      assert( (pRecTerm->pNext->selFlags & SF_Recursive)!=0 );
+      assert( pRecTerm->pWith==0 );
+      pRecTerm->pWith = pSel->pWith;
+      sqlite3WalkSelect(pWalker, pRecTerm);
+      pRecTerm->pWith = 0;
    }else{
      sqlite3WalkSelect(pWalker, pSel);
    }
@@ -5585,7 +5615,9 @@ static void explainSimpleCount(
 static int havingToWhereExprCb(Walker *pWalker, Expr *pExpr){
  if( pExpr->op!=TK_AND ){
    Select *pS = pWalker->u.pSelect;
-    if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy) ){
+    if( sqlite3ExprIsConstantOrGroupBy(pWalker->pParse, pExpr, pS->pGroupBy) 
+     && ExprAlwaysFalse(pExpr)==0
+    ){
      sqlite3 *db = pWalker->pParse->db;
      Expr *pNew = sqlite3Expr(db, TK_INTEGER, "1");
      if( pNew ){
@@ -5624,7 +5656,7 @@ static void havingToWhere(Parse *pParse, Select *p){
  sWalker.u.pSelect = p;
  sqlite3WalkExpr(&sWalker, p->pHaving);
 #if SELECTTRACE_ENABLED
-  if( sWalker.eCode && (sqlite3SelectTrace & 0x100)!=0 ){
+  if( sWalker.eCode && (sqlite3_unsupported_selecttrace & 0x100)!=0 ){
    SELECTTRACE(0x100,pParse,p,("Move HAVING terms into WHERE:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
@@ -5746,7 +5778,7 @@ static int countOfViewOptimization(Parse *pParse, Select *p){
  p->selFlags &= ~SF_Aggregate;

 #if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x400 ){
+  if( sqlite3_unsupported_selecttrace & 0x400 ){
    SELECTTRACE(0x400,pParse,p,("After count-of-view optimization:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
@@ -5799,7 +5831,7 @@ int sqlite3Select(
  if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1;
 #if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p, ("begin processing:\n", pParse->addrExplain));
-  if( sqlite3SelectTrace & 0x100 ){
+  if( sqlite3_unsupported_selecttrace & 0x100 ){
    sqlite3TreeViewSelect(0, p, 0);
  }
 #endif
@@ -5808,13 +5840,11 @@ int sqlite3Select(
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo );
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue );
  assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue );
-  if( IgnorableOrderby(pDest) ){
-    assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || 
-           pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard ||
-           pDest->eDest==SRT_Queue  || pDest->eDest==SRT_DistFifo ||
-           pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo);
-    /* If ORDER BY makes no difference in the output then neither does
-    ** DISTINCT so it can be removed too. */
+  if( IgnorableDistinct(pDest) ){
+    assert(pDest->eDest==SRT_Exists     || pDest->eDest==SRT_Union || 
+           pDest->eDest==SRT_Except     || pDest->eDest==SRT_Discard ||
+           pDest->eDest==SRT_DistQueue  || pDest->eDest==SRT_DistFifo );
+    /* All of these destinations are also able to ignore the ORDER BY clause */
    sqlite3ExprListDelete(db, p->pOrderBy);
    p->pOrderBy = 0;
    p->selFlags &= ~SF_Distinct;
@@ -5826,7 +5856,7 @@ int sqlite3Select(
  }
  assert( p->pEList!=0 );
 #if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x104 ){
+  if( sqlite3_unsupported_selecttrace & 0x104 ){
    SELECTTRACE(0x104,pParse,p, ("after name resolution:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
@@ -5861,7 +5891,7 @@ int sqlite3Select(
    goto select_end;
  }
 #if SELECTTRACE_ENABLED
-  if( p->pWin && (sqlite3SelectTrace & 0x108)!=0 ){
+  if( p->pWin && (sqlite3_unsupported_selecttrace & 0x108)!=0 ){
    SELECTTRACE(0x104,pParse,p, ("after window rewrite:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
@@ -5968,7 +5998,7 @@ int sqlite3Select(
    rc = multiSelect(pParse, p, pDest);
 #if SELECTTRACE_ENABLED
    SELECTTRACE(0x1,pParse,p,("end compound-select processing\n"));
-    if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
+    if( (sqlite3_unsupported_selecttrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
      sqlite3TreeViewSelect(0, p, 0);
    }
 #endif
@@ -5987,7 +6017,7 @@ int sqlite3Select(
   && propagateConstants(pParse, p)
  ){
 #if SELECTTRACE_ENABLED
-    if( sqlite3SelectTrace & 0x100 ){
+    if( sqlite3_unsupported_selecttrace & 0x100 ){
      SELECTTRACE(0x100,pParse,p,("After constant propagation:\n"));
      sqlite3TreeViewSelect(0, p, 0);
    }
@@ -6075,7 +6105,7 @@ int sqlite3Select(
                           (pItem->fg.jointype & JT_OUTER)!=0)
    ){
 #if SELECTTRACE_ENABLED
-      if( sqlite3SelectTrace & 0x100 ){
+      if( sqlite3_unsupported_selecttrace & 0x100 ){
        SELECTTRACE(0x100,pParse,p,
            ("After WHERE-clause push-down into subquery %d:\n", pSub->selId));
        sqlite3TreeViewSelect(0, p, 0);
@@ -6175,7 +6205,7 @@ int sqlite3Select(
  sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0;

 #if SELECTTRACE_ENABLED
-  if( sqlite3SelectTrace & 0x400 ){
+  if( sqlite3_unsupported_selecttrace & 0x400 ){
    SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
@@ -6211,7 +6241,7 @@ int sqlite3Select(
    assert( sDistinct.isTnct );

 #if SELECTTRACE_ENABLED
-    if( sqlite3SelectTrace & 0x400 ){
+    if( sqlite3_unsupported_selecttrace & 0x400 ){
      SELECTTRACE(0x400,pParse,p,("Transform DISTINCT into GROUP BY:\n"));
      sqlite3TreeViewSelect(0, p, 0);
    }
@@ -6459,7 +6489,7 @@ int sqlite3Select(
    pAggInfo->mxReg = pParse->nMem;
    if( db->mallocFailed ) goto select_end;
 #if SELECTTRACE_ENABLED
-    if( sqlite3SelectTrace & 0x400 ){
+    if( sqlite3_unsupported_selecttrace & 0x400 ){
      int ii;
      SELECTTRACE(0x400,pParse,p,("After aggregate analysis %p:\n", pAggInfo));
      sqlite3TreeViewSelect(0, p, 0);
@@ -6878,7 +6908,7 @@ select_end:

 #if SELECTTRACE_ENABLED
  SELECTTRACE(0x1,pParse,p,("end processing\n"));
-  if( (sqlite3SelectTrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
+  if( (sqlite3_unsupported_selecttrace & 0x2000)!=0 && ExplainQueryPlanParent(pParse)==0 ){
    sqlite3TreeViewSelect(0, p, 0);
  }
 #endif
@@ -553,8 +553,6 @@ static void utf8_width_print(FILE *pOut, int w, const char *zUtf){
  int i;
  int n;
  int aw = w<0 ? -w : w;
-  char zBuf[1000];
-  if( aw>(int)sizeof(zBuf)/3 ) aw = (int)sizeof(zBuf)/3;
  for(i=n=0; zUtf[i]; i++){
    if( (zUtf[i]&0xc0)!=0x80 ){
      n++;
@@ -1028,6 +1026,7 @@ INCLUDE ../ext/misc/memtrace.c
 INCLUDE ../ext/misc/uint.c
 INCLUDE ../ext/misc/decimal.c
 INCLUDE ../ext/misc/ieee754.c
+INCLUDE ../ext/misc/series.c
 #ifdef SQLITE_HAVE_ZLIB
 INCLUDE ../ext/misc/zipfile.c
 INCLUDE ../ext/misc/sqlar.c
@@ -1185,6 +1184,8 @@ struct ShellState {
 #define SHFLG_CountChanges   0x00000020 /* .changes setting */
 #define SHFLG_Echo           0x00000040 /* .echo or --echo setting */
 #define SHFLG_HeaderSet      0x00000080 /* .header has been used */
+#define SHFLG_DumpDataOnly   0x00000100 /* .dump show data only */
+#define SHFLG_DumpNoSys      0x00000200 /* .dump omits system tables */

 /*
 ** Macros for testing and setting shellFlgs
@@ -2881,7 +2882,7 @@ static void explain_data_delete(ShellState *p){
 ** Disable and restore .wheretrace and .selecttrace settings.
 */
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
-extern int sqlite3SelectTrace;
+extern unsigned int sqlite3_unsupported_selecttrace;
 static int savedSelectTrace;
 #endif
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
@@ -2890,8 +2891,8 @@ static int savedWhereTrace;
 #endif
 static void disable_debug_trace_modes(void){
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
-  savedSelectTrace = sqlite3SelectTrace;
-  sqlite3SelectTrace = 0;
+  savedSelectTrace = sqlite3_unsupported_selecttrace;
+  sqlite3_unsupported_selecttrace = 0;
 #endif
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  savedWhereTrace = sqlite3WhereTrace;
@@ -2900,7 +2901,7 @@ static void disable_debug_trace_modes(void){
 }
 static void restore_debug_trace_modes(void){
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
-  sqlite3SelectTrace = savedSelectTrace;
+  sqlite3_unsupported_selecttrace = savedSelectTrace;
 #endif
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_WHERETRACE)
  sqlite3WhereTrace = savedWhereTrace;
@@ -3051,25 +3052,38 @@ static void exec_prepared_stmt_columnar(
  ShellState *p,                        /* Pointer to ShellState */
  sqlite3_stmt *pStmt                   /* Statment to run */
 ){
-  int nRow = 0;
+  sqlite3_int64 nRow = 0;
  int nColumn = 0;
  char **azData = 0;
-  char *zMsg = 0;
+  sqlite3_int64 nAlloc = 0;
  const char *z;
  int rc;
-  int i, j, nTotal, w, n;
+  sqlite3_int64 i, nData;
+  int j, nTotal, w, n;
  const char *colSep = 0;
  const char *rowSep = 0;

-  rc = sqlite3_get_table(p->db, sqlite3_sql(pStmt),
-                         &azData, &nRow, &nColumn, &zMsg);
-  if( rc ){
-    utf8_printf(p->out, "ERROR: %s\n", zMsg);
-    sqlite3_free(zMsg);
-    sqlite3_free_table(azData);
-    return;
+  rc = sqlite3_step(pStmt);
+  if( rc!=SQLITE_ROW ) return;
+  nColumn = sqlite3_column_count(pStmt);
+  nAlloc = nColumn*4;
+  azData = sqlite3_malloc64( nAlloc*sizeof(char*) );
+  if( azData==0 ) shell_out_of_memory();
+  for(i=0; i<nColumn; i++){
+    azData[i] = strdup(sqlite3_column_name(pStmt,i));
  }
-  if( nRow==0 || nColumn==0 ) goto columnar_end;
+  do{
+    if( (nRow+2)*nColumn >= nAlloc ){
+      nAlloc *= 2;
+      azData = sqlite3_realloc64(azData, nAlloc*sizeof(char*));
+      if( azData==0 ) shell_out_of_memory();
+    }
+    nRow++;
+    for(i=0; i<nColumn; i++){
+      z = (const char*)sqlite3_column_text(pStmt,i);
+      azData[nRow*nColumn + i] = z ? strdup(z) : 0;
+    }
+  }while( (rc = sqlite3_step(pStmt))==SQLITE_ROW );
  if( nColumn>p->nWidth ){
    p->colWidth = realloc(p->colWidth, nColumn*2*sizeof(int));
    if( p->colWidth==0 ) shell_out_of_memory();
@@ -3179,7 +3193,9 @@ columnar_end:
  if( seenInterrupt ){
    utf8_printf(p->out, "Interrupt\n");
  }
-  sqlite3_free_table(azData);
+  nData = (nRow+1)*nColumn;
+  for(i=0; i<nData; i++) free(azData[i]);
+  sqlite3_free(azData);
 }

 /*
@@ -3690,19 +3706,25 @@ static int dump_callback(void *pArg, int nArg, char **azArg, char **azNotUsed){
  const char *zType;
  const char *zSql;
  ShellState *p = (ShellState *)pArg;
+  int dataOnly;
+  int noSys;

  UNUSED_PARAMETER(azNotUsed);
  if( nArg!=3 || azArg==0 ) return 0;
  zTable = azArg[0];
  zType = azArg[1];
  zSql = azArg[2];
+  dataOnly = (p->shellFlgs & SHFLG_DumpDataOnly)!=0;
+  noSys    = (p->shellFlgs & SHFLG_DumpNoSys)!=0;

-  if( strcmp(zTable, "sqlite_sequence")==0 ){
-    raw_printf(p->out, "DELETE FROM sqlite_sequence;\n");
-  }else if( sqlite3_strglob("sqlite_stat?", zTable)==0 ){
-    raw_printf(p->out, "ANALYZE sqlite_schema;\n");
+  if( strcmp(zTable, "sqlite_sequence")==0 && !noSys ){
+    if( !dataOnly ) raw_printf(p->out, "DELETE FROM sqlite_sequence;\n");
+  }else if( sqlite3_strglob("sqlite_stat?", zTable)==0 && !noSys ){
+    if( !dataOnly ) raw_printf(p->out, "ANALYZE sqlite_schema;\n");
  }else if( strncmp(zTable, "sqlite_", 7)==0 ){
    return 0;
+  }else if( dataOnly ){
+    /* no-op */
  }else if( strncmp(zSql, "CREATE VIRTUAL TABLE", 20)==0 ){
    char *zIns;
    if( !p->writableSchema ){
@@ -3875,8 +3897,10 @@ static const char *(azHelp[]) = {
  ".dbinfo ?DB?             Show status information about the database",
  ".dump ?TABLE?            Render database content as SQL",
  "   Options:",
-  "     --preserve-rowids      Include ROWID values in the output",
+  "     --data-only            Output only INSERT statements",
  "     --newlines             Allow unescaped newline characters in output",
+  "     --nosys                Omit system tables (ex: \"sqlite_stat1\")",
+  "     --preserve-rowids      Include ROWID values in the output",
  "   TABLE is a LIKE pattern for the tables to dump",
  "   Additional LIKE patterns can be given in subsequent arguments",
  ".echo on|off             Turn command echo on or off",
@@ -4001,8 +4025,9 @@ static const char *(azHelp[]) = {
  ".save FILE               Write in-memory database into FILE",
  ".scanstats on|off        Turn sqlite3_stmt_scanstatus() metrics on or off",
  ".schema ?PATTERN?        Show the CREATE statements matching PATTERN",
-  "     Options:",
-  "         --indent            Try to pretty-print the schema",
+  "   Options:",
+  "      --indent             Try to pretty-print the schema",
+  "      --nosys              Omit objects whose names start with \"sqlite_\"",
  ".selftest ?OPTIONS?      Run tests defined in the SELFTEST table",
  "    Options:",
  "       --init               Create a new SELFTEST table",
@@ -4411,6 +4436,20 @@ static void shellIdQuote(
  }
 }

+/*
+** Scalar function "usleep(X)" invokes sqlite3_sleep(X) and returns X.
+*/
+static void shellUSleepFunc(
+  sqlite3_context *context, 
+  int argcUnused, 
+  sqlite3_value **argv
+){
+  int sleep = sqlite3_value_int(argv[0]);
+  (void)argcUnused;
+  sqlite3_sleep(sleep/1000);
+  sqlite3_result_int(context, sleep);
+}
+
 /*
 ** Scalar function "shell_escape_crnl" used by the .recover command.
 ** The argument passed to this function is the output of built-in
@@ -4575,6 +4614,7 @@ static void open_db(ShellState *p, int openFlags){
    sqlite3_uint_init(p->db, 0, 0);
    sqlite3_decimal_init(p->db, 0, 0);
    sqlite3_ieee_init(p->db, 0, 0);
+    sqlite3_series_init(p->db, 0, 0);
 #if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_ENABLE_DBPAGE_VTAB)
    sqlite3_dbdata_init(p->db, 0, 0);
 #endif
@@ -4594,6 +4634,8 @@ static void open_db(ShellState *p, int openFlags){
                            shellInt32, 0, 0);
    sqlite3_create_function(p->db, "shell_idquote", 1, SQLITE_UTF8, 0,
                            shellIdQuote, 0, 0);
+    sqlite3_create_function(p->db, "usleep",1,SQLITE_UTF8,0,
+                            shellUSleepFunc, 0, 0);
 #ifndef SQLITE_NOHAVE_SYSTEM
    sqlite3_create_function(p->db, "edit", 1, SQLITE_UTF8, 0,
                            editFunc, 0, 0);
@@ -7568,21 +7610,41 @@ static int do_meta_command(char *zLine, ShellState *p){
  }else

  if( c=='d' && n>1 && strncmp(azArg[0], "databases", n)==0 ){
-    ShellState data;
-    char *zErrMsg = 0;
+    char **azName = 0;
+    int nName = 0;
+    sqlite3_stmt *pStmt;
+    int i;
    open_db(p, 0);
-    memcpy(&data, p, sizeof(data));
-    data.showHeader = 0;
-    data.cMode = data.mode = MODE_List;
-    sqlite3_snprintf(sizeof(data.colSeparator),data.colSeparator,": ");
-    data.cnt = 0;
-    sqlite3_exec(p->db, "SELECT name, file FROM pragma_database_list",
-                 callback, &data, &zErrMsg);
-    if( zErrMsg ){
-      utf8_printf(stderr,"Error: %s\n", zErrMsg);
-      sqlite3_free(zErrMsg);
+    rc = sqlite3_prepare_v2(p->db, "PRAGMA database_list", -1, &pStmt, 0);
+    if( rc ){
+      utf8_printf(stderr, "Error: %s\n", sqlite3_errmsg(p->db));
      rc = 1;
+    }else{
+      while( sqlite3_step(pStmt)==SQLITE_ROW ){
+        const char *zSchema = (const char *)sqlite3_column_text(pStmt,1);
+        const char *zFile = (const char*)sqlite3_column_text(pStmt,2);
+        azName = sqlite3_realloc(azName, (nName+1)*2*sizeof(char*));
+        if( azName==0 ){ shell_out_of_memory();  /* Does not return */ }
+        azName[nName*2] = strdup(zSchema);
+        azName[nName*2+1] = strdup(zFile);
+        nName++;
+      }
    }
+    sqlite3_finalize(pStmt);
+    for(i=0; i<nName; i++){
+      int eTxn = sqlite3_txn_state(p->db, azName[i*2]);
+      int bRdonly = sqlite3_db_readonly(p->db, azName[i*2]);
+      const char *z = azName[i*2+1];
+      utf8_printf(p->out, "%s: %s %s%s\n",
+         azName[i*2],
+         z && z[0] ? z : "\"\"",
+         bRdonly ? "r/o" : "r/w",
+         eTxn==SQLITE_TXN_NONE ? "" :
+            eTxn==SQLITE_TXN_READ ? " read-txn" : " write-txn");
+      free(azName[i*2]);
+      free(azName[i*2+1]);
+    }
+    sqlite3_free(azName);
  }else

  if( c=='d' && n>=3 && strncmp(azArg[0], "dbconfig", n)==0 ){
@@ -7641,7 +7703,9 @@ static int do_meta_command(char *zLine, ShellState *p){
    int i;
    int savedShowHeader = p->showHeader;
    int savedShellFlags = p->shellFlgs;
-    ShellClearFlag(p, SHFLG_PreserveRowid|SHFLG_Newlines|SHFLG_Echo);
+    ShellClearFlag(p, 
+       SHFLG_PreserveRowid|SHFLG_Newlines|SHFLG_Echo
+       |SHFLG_DumpDataOnly|SHFLG_DumpNoSys);
    for(i=1; i<nArg; i++){
      if( azArg[i][0]=='-' ){
        const char *z = azArg[i]+1;
@@ -7660,6 +7724,12 @@ static int do_meta_command(char *zLine, ShellState *p){
        if( strcmp(z,"newlines")==0 ){
          ShellSetFlag(p, SHFLG_Newlines);
        }else
+        if( strcmp(z,"data-only")==0 ){
+          ShellSetFlag(p, SHFLG_DumpDataOnly);
+        }else
+        if( strcmp(z,"nosys")==0 ){
+          ShellSetFlag(p, SHFLG_DumpNoSys);
+        }else
        {
          raw_printf(stderr, "Unknown option \"%s\" on \".dump\"\n", azArg[i]);
          rc = 1;
@@ -7676,11 +7746,13 @@ static int do_meta_command(char *zLine, ShellState *p){

    open_db(p, 0);

-    /* When playing back a "dump", the content might appear in an order
-    ** which causes immediate foreign key constraints to be violated.
-    ** So disable foreign-key constraint enforcement to prevent problems. */
-    raw_printf(p->out, "PRAGMA foreign_keys=OFF;\n");
-    raw_printf(p->out, "BEGIN TRANSACTION;\n");
+    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
+      /* When playing back a "dump", the content might appear in an order
+      ** which causes immediate foreign key constraints to be violated.
+      ** So disable foreign-key constraint enforcement to prevent problems. */
+      raw_printf(p->out, "PRAGMA foreign_keys=OFF;\n");
+      raw_printf(p->out, "BEGIN TRANSACTION;\n");
+    }
    p->writableSchema = 0;
    p->showHeader = 0;
    /* Set writable_schema=ON since doing so forces SQLite to initialize
@@ -7698,14 +7770,16 @@ static int do_meta_command(char *zLine, ShellState *p){
    );
    run_schema_dump_query(p,zSql);
    sqlite3_free(zSql);
-    zSql = sqlite3_mprintf(
-      "SELECT sql FROM sqlite_schema "
-      "WHERE (%s) AND sql NOT NULL"
-      "  AND type IN ('index','trigger','view')",
-      zLike
-    );
-    run_table_dump_query(p, zSql);
-    sqlite3_free(zSql);
+    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
+      zSql = sqlite3_mprintf(
+        "SELECT sql FROM sqlite_schema "
+        "WHERE (%s) AND sql NOT NULL"
+        "  AND type IN ('index','trigger','view')",
+        zLike
+      );
+      run_table_dump_query(p, zSql);
+      sqlite3_free(zSql);
+    }
    sqlite3_free(zLike);
    if( p->writableSchema ){
      raw_printf(p->out, "PRAGMA writable_schema=OFF;\n");
@@ -7713,7 +7787,9 @@ static int do_meta_command(char *zLine, ShellState *p){
    }
    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
    sqlite3_exec(p->db, "RELEASE dump;", 0, 0, 0);
-    raw_printf(p->out, p->nErr?"ROLLBACK; -- due to errors\n":"COMMIT;\n");
+    if( (p->shellFlgs & SHFLG_DumpDataOnly)==0 ){
+      raw_printf(p->out, p->nErr?"ROLLBACK; -- due to errors\n":"COMMIT;\n");
+    }
    p->showHeader = savedShowHeader;
    p->shellFlgs = savedShellFlags;
  }else
@@ -8152,7 +8228,7 @@ static int do_meta_command(char *zLine, ShellState *p){
    while( (nSkip--)>0 ){
      while( xRead(&sCtx) && sCtx.cTerm==sCtx.cColSep ){}
    }
-    zSql = sqlite3_mprintf("SELECT * FROM %s", zTable);
+    zSql = sqlite3_mprintf("SELECT * FROM \"%w\"", zTable);
    if( zSql==0 ){
      import_cleanup(&sCtx);
      shell_out_of_memory();
@@ -8161,7 +8237,7 @@ static int do_meta_command(char *zLine, ShellState *p){
    rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
    import_append_char(&sCtx, 0);    /* To ensure sCtx.z is allocated */
    if( rc && sqlite3_strglob("no such table: *", sqlite3_errmsg(p->db))==0 ){
-      char *zCreate = sqlite3_mprintf("CREATE TABLE %s", zTable);
+      char *zCreate = sqlite3_mprintf("CREATE TABLE \"%w\"", zTable);
      char cSep = '(';
      while( xRead(&sCtx) ){
        zCreate = sqlite3_mprintf("%z%c\n  \"%w\" TEXT", zCreate, cSep, sCtx.z);
@@ -8182,7 +8258,7 @@ static int do_meta_command(char *zLine, ShellState *p){
      rc = sqlite3_exec(p->db, zCreate, 0, 0, 0);
      sqlite3_free(zCreate);
      if( rc ){
-        utf8_printf(stderr, "CREATE TABLE %s(...) failed: %s\n", zTable,
+        utf8_printf(stderr, "CREATE TABLE \"%s\"(...) failed: %s\n", zTable,
                sqlite3_errmsg(p->db));
        import_cleanup(&sCtx);
        rc = 1;
@@ -8947,9 +9023,16 @@ static int do_meta_command(char *zLine, ShellState *p){
      rc = 1;
      goto meta_command_exit;
    }
-    if( notNormalFile(azArg[1])
-     || (p->in = fopen(azArg[1], "rb"))==0
-    ){
+    if( azArg[1][0]=='|' ){
+      p->in = popen(azArg[1]+1, "r");
+      if( p->in==0 ){
+        utf8_printf(stderr, "Error: cannot open \"%s\"\n", azArg[1]);
+        rc = 1;
+      }else{
+        rc = process_input(p);
+        pclose(p->in);
+      }
+    }else if( notNormalFile(azArg[1]) || (p->in = fopen(azArg[1], "rb"))==0 ){
      utf8_printf(stderr,"Error: cannot open \"%s\"\n", azArg[1]);
      rc = 1;
    }else{
@@ -9031,6 +9114,7 @@ static int do_meta_command(char *zLine, ShellState *p){
    const char *zName = 0;
    int iSchema = 0;
    int bDebug = 0;
+    int bNoSystemTabs = 0;
    int ii;

    open_db(p, 0);
@@ -9043,10 +9127,16 @@ static int do_meta_command(char *zLine, ShellState *p){
        data.cMode = data.mode = MODE_Pretty;
      }else if( optionMatch(azArg[ii],"debug") ){
        bDebug = 1;
+      }else if( optionMatch(azArg[ii],"nosys") ){
+        bNoSystemTabs = 1;
+      }else if( azArg[ii][0]=='-' ){
+        utf8_printf(stderr, "Unknown option: \"%s\"\n", azArg[ii]);
+        rc = 1;
+        goto meta_command_exit;
      }else if( zName==0 ){
        zName = azArg[ii];
      }else{
-        raw_printf(stderr, "Usage: .schema ?--indent? ?LIKE-PATTERN?\n");
+        raw_printf(stderr, "Usage: .schema ?--indent? ?--nosys? ?LIKE-PATTERN?\n");
        rc = 1;
        goto meta_command_exit;
      }
@@ -9132,7 +9222,10 @@ static int do_meta_command(char *zLine, ShellState *p){
        appendText(&sSelect, " AND ", 0);
        sqlite3_free(zQarg);
      }
-      appendText(&sSelect, "type!='meta' AND sql IS NOT NULL"
+      if( bNoSystemTabs ){
+        appendText(&sSelect, "name NOT LIKE 'sqlite_%%' AND ", 0);
+      }
+      appendText(&sSelect, "sql IS NOT NULL"
                           " ORDER BY snum, rowid", 0);
      if( bDebug ){
        utf8_printf(p->out, "SQL: %s;\n", sSelect.z);
@@ -9155,7 +9248,7 @@ static int do_meta_command(char *zLine, ShellState *p){

 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
  if( c=='s' && n==11 && strncmp(azArg[0], "selecttrace", n)==0 ){
-    sqlite3SelectTrace = nArg>=2 ? (int)integerValue(azArg[1]) : 0xffff;
+    sqlite3_unsupported_selecttrace = nArg>=2 ? (int)integerValue(azArg[1]) : 0xffff;
  }else
 #endif

@@ -9829,6 +9922,7 @@ static int do_meta_command(char *zLine, ShellState *p){
      { "prng_restore",       SQLITE_TESTCTRL_PRNG_RESTORE,  ""               },
      { "prng_save",          SQLITE_TESTCTRL_PRNG_SAVE,     ""               },
      { "prng_seed",          SQLITE_TESTCTRL_PRNG_SEED,     "SEED ?db?"      },
+      { "seek_count",         SQLITE_TESTCTRL_SEEK_COUNT,    ""               },
    };
    int testctrl = -1;
    int iCtrl = -1;
@@ -9891,7 +9985,6 @@ static int do_meta_command(char *zLine, ShellState *p){
        /* sqlite3_test_control(int) */
        case SQLITE_TESTCTRL_PRNG_SAVE:
        case SQLITE_TESTCTRL_PRNG_RESTORE:
-        case SQLITE_TESTCTRL_PRNG_RESET:
        case SQLITE_TESTCTRL_BYTEORDER:
          if( nArg==2 ){
            rc2 = sqlite3_test_control(testctrl);
@@ -9965,6 +10058,14 @@ static int do_meta_command(char *zLine, ShellState *p){
          }
          break;

+        case SQLITE_TESTCTRL_SEEK_COUNT: {
+          u64 x = 0;
+          rc2 = sqlite3_test_control(testctrl, p->db, &x);
+          utf8_printf(p->out, "%llu\n", x);
+          isOk = 3;
+          break;
+        }
+
 #ifdef YYCOVERAGE
        case SQLITE_TESTCTRL_PARSER_COVERAGE:
          if( nArg==2 ){
@@ -10543,8 +10644,11 @@ static void process_sqliterc(
    if( stdin_is_interactive ){
      utf8_printf(stderr,"-- Loading resources from %s\n",sqliterc);
    }
-    process_input(p);
+    if( process_input(p) && bail_on_error ) exit(1);
    fclose(p->in);
+  }else if( sqliterc_override!=0 ){
+    utf8_printf(stderr,"cannot open: \"%s\"\n", sqliterc);
+    if( bail_on_error ) exit(1);
  }
  p->in = inSaved;
  p->lineno = savedLineno;
@@ -10603,6 +10707,7 @@ static const char zOptions[] =
 #endif
  "   -stats               print memory stats before each finalize\n"
  "   -table               set output mode to 'table'\n"
+  "   -tabs                set output mode to 'tabs'\n"
  "   -version             show SQLite version\n"
  "   -vfs NAME            use NAME as the default VFS\n"
 #ifdef SQLITE_ENABLE_VFSTRACE
@@ -10860,11 +10965,14 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
      (void)cmdline_option_value(argc, argv, ++i);
 #endif
    }else if( strcmp(z,"-pagecache")==0 ){
-      int n, sz;
-      sz = (int)integerValue(cmdline_option_value(argc,argv,++i));
+      sqlite3_int64 n, sz;
+      sz = integerValue(cmdline_option_value(argc,argv,++i));
      if( sz>70000 ) sz = 70000;
      if( sz<0 ) sz = 0;
-      n = (int)integerValue(cmdline_option_value(argc,argv,++i));
+      n = integerValue(cmdline_option_value(argc,argv,++i));
+      if( sz>0 && n>0 && 0xffffffffffffLL/sz<n ){
+        n = 0xffffffffffffLL/sz;
+      }
      sqlite3_config(SQLITE_CONFIG_PAGECACHE,
                    (n>0 && sz>0) ? malloc(n*sz) : 0, sz, n);
      data.shellFlgs |= SHFLG_Pagecache;
@@ -10926,6 +11034,8 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
 #endif
    }else if( strcmp(z, "-memtrace")==0 ){
      sqlite3MemTraceActivate(stderr);
+    }else if( strcmp(z,"-bail")==0 ){
+      bail_on_error = 1;
    }
  }
  verify_uninitialized();
@@ -11000,6 +11110,8 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
      data.mode = MODE_List;
    }else if( strcmp(z,"-quote")==0 ){
      data.mode = MODE_Quote;
+      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator, SEP_Comma);
+      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator, SEP_Row);
    }else if( strcmp(z,"-line")==0 ){
      data.mode = MODE_Line;
    }else if( strcmp(z,"-column")==0 ){
@@ -11033,10 +11145,12 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
      data.openFlags |= SQLITE_OPEN_NOFOLLOW;
    }else if( strcmp(z,"-ascii")==0 ){
      data.mode = MODE_Ascii;
-      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator,
-                       SEP_Unit);
-      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator,
-                       SEP_Record);
+      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator, SEP_Unit);
+      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator, SEP_Record);
+    }else if( strcmp(z,"-tabs")==0 ){
+      data.mode = MODE_List;
+      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator, SEP_Tab);
+      sqlite3_snprintf(sizeof(data.rowSeparator), data.rowSeparator, SEP_Row);
    }else if( strcmp(z,"-separator")==0 ){
      sqlite3_snprintf(sizeof(data.colSeparator), data.colSeparator,
                       "%s",cmdline_option_value(argc,argv,++i));
@@ -11068,7 +11182,7 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
      */
      ShellSetFlag(&data, SHFLG_Backslash);
    }else if( strcmp(z,"-bail")==0 ){
-      bail_on_error = 1;
+      /* No-op.  The bail_on_error flag should already be set. */
    }else if( strcmp(z,"-version")==0 ){
      printf("%s %s\n", sqlite3_libversion(), sqlite3_sourceid());
      return 0;
@@ -11156,20 +11270,25 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
    for(i=0; i<nCmd; i++){
      if( azCmd[i][0]=='.' ){
        rc = do_meta_command(azCmd[i], &data);
-        if( rc ) return rc==2 ? 0 : rc;
+        if( rc ){
+          free(azCmd);
+          return rc==2 ? 0 : rc;
+        }
      }else{
        open_db(&data, 0);
        rc = shell_exec(&data, azCmd[i], &zErrMsg);
-        if( zErrMsg!=0 ){
-          utf8_printf(stderr,"Error: %s\n", zErrMsg);
+        if( zErrMsg || rc ){
+          if( zErrMsg!=0 ){
+            utf8_printf(stderr,"Error: %s\n", zErrMsg);
+          }else{
+            utf8_printf(stderr,"Error: unable to process SQL: %s\n", azCmd[i]);
+          }
+          sqlite3_free(zErrMsg);
+          free(azCmd);
          return rc!=0 ? rc : 1;
-        }else if( rc!=0 ){
-          utf8_printf(stderr,"Error: unable to process SQL: %s\n", azCmd[i]);
-          return rc;
        }
      }
    }
-    free(azCmd);
  }else{
    /* Run commands received from standard input
    */
@@ -11215,6 +11334,7 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
      rc = process_input(&data);
    }
  }
+  free(azCmd);
  set_table_name(&data, 0);
  if( data.db ){
    session_close_all(&data);
@@ -504,6 +504,7 @@ int sqlite3_exec(
 #define SQLITE_IOERR_COMMIT_ATOMIC     (SQLITE_IOERR | (30<<8))
 #define SQLITE_IOERR_ROLLBACK_ATOMIC   (SQLITE_IOERR | (31<<8))
 #define SQLITE_IOERR_DATA              (SQLITE_IOERR | (32<<8))
+#define SQLITE_IOERR_CORRUPTFS         (SQLITE_IOERR | (33<<8))
 #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
 #define SQLITE_LOCKED_VTAB             (SQLITE_LOCKED |  (2<<8))
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
@@ -3696,7 +3697,7 @@ sqlite3_file *sqlite3_database_file_object(const char*);
 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
 ** than a NULL pointer or a pointer previously acquired from
 ** sqlite3_create_filename(), then bad things such as heap
-** corruption or segfaults may occur. The value Y should be 
+** corruption or segfaults may occur. The value Y should not be 
 ** used again after sqlite3_free_filename(Y) has been called.  This means
 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
 ** then the corresponding [sqlite3_module.xClose() method should also be
@@ -6186,6 +6187,57 @@ const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
 */
 int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);

+/*
+** CAPI3REF: Determine the transaction state of a database
+** METHOD: sqlite3
+**
+** ^The sqlite3_txn_state(D,S) interface returns the current
+** [transaction state] of schema S in database connection D.  ^If S is NULL,
+** then the highest transaction state of any schema on database connection D
+** is returned.  Transaction states are (in order of lowest to highest):
+** <ol>
+** <li value="0"> SQLITE_TXN_NONE
+** <li value="1"> SQLITE_TXN_READ
+** <li value="2"> SQLITE_TXN_WRITE
+** </ol>
+** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
+** a valid schema, then -1 is returned.
+*/
+int sqlite3_txn_state(sqlite3*,const char *zSchema);
+
+/*
+** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
+** KEYWORDS: {transaction state}
+**
+** These constants define the current transaction state of a database file.
+** ^The [sqlite3_txn_state(D,S)] interface returns one of these
+** constants in order to describe the transaction state of schema S
+** in [database connection] D.
+**
+** <dl>
+** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
+** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
+** pending.</dd>
+**
+** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
+** <dd>The SQLITE_TXN_READ state means that the database is currently
+** in a read transaction.  Content has been read from the database file
+** but nothing in the database file has changed.  The transaction state
+** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
+** no other conflicting concurrent write transactions.  The transaction
+** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
+** [COMMIT].</dd>
+**
+** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
+** <dd>The SQLITE_TXN_WRITE state means that the database is currently
+** in a write transaction.  Content has been written to the database file
+** but has not yet committed.  The transaction state will change to
+** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
+*/
+#define SQLITE_TXN_NONE  0
+#define SQLITE_TXN_READ  1
+#define SQLITE_TXN_WRITE 2
+
 /*
 ** CAPI3REF: Find the next prepared statement
 ** METHOD: sqlite3
@@ -7712,7 +7764,8 @@ int sqlite3_test_control(int op, ...);
 #define SQLITE_TESTCTRL_RESULT_INTREAL          27
 #define SQLITE_TESTCTRL_PRNG_SEED               28
 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS     29
-#define SQLITE_TESTCTRL_LAST                    29  /* Largest TESTCTRL */
+#define SQLITE_TESTCTRL_SEEK_COUNT              30
+#define SQLITE_TESTCTRL_LAST                    30  /* Largest TESTCTRL */

 /*
 ** CAPI3REF: SQL Keyword Checking
@@ -9192,10 +9245,11 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
 **
 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
-** method of a [virtual table], then it returns true if and only if the
+** method of a [virtual table], then it might return true if the
 ** column is being fetched as part of an UPDATE operation during which the
-** column value will not change.  Applications might use this to substitute
-** a return value that is less expensive to compute and that the corresponding
+** column value will not change.  The virtual table implementation can use
+** this hint as permission to substitute a return value that is less
+** expensive to compute and that the corresponding
 ** [xUpdate] method understands as a "no-change" value.
 **
 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
@@ -9204,6 +9258,12 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
 ** In that case, [sqlite3_value_nochange(X)] will return true for the
 ** same column in the [xUpdate] method.
+**
+** The sqlite3_vtab_nochange() routine is an optimization.  Virtual table
+** implementations should continue to give a correct answer even if the
+** sqlite3_vtab_nochange() interface were to always return false.  In the
+** current implementation, the sqlite3_vtab_nochange() interface does always
+** returns false for the enhanced [UPDATE FROM] statement.
 */
 int sqlite3_vtab_nochange(sqlite3_context*);

@@ -9345,6 +9405,7 @@ void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);

 /*
 ** CAPI3REF: Flush caches to disk mid-transaction
+** METHOD: sqlite3
 **
 ** ^If a write-transaction is open on [database connection] D when the
 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
@@ -9377,6 +9438,7 @@ int sqlite3_db_cacheflush(sqlite3*);

 /*
 ** CAPI3REF: The pre-update hook.
+** METHOD: sqlite3
 **
 ** ^These interfaces are only available if SQLite is compiled using the
 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
@@ -9417,7 +9479,7 @@ int sqlite3_db_cacheflush(sqlite3*);
 ** seventh parameter is the final rowid value of the row being inserted
 ** or updated. The value of the seventh parameter passed to the callback
 ** function is not defined for operations on WITHOUT ROWID tables, or for
-** INSERT operations on rowid tables.
+** DELETE operations on rowid tables.
 **
 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
@@ -9479,6 +9541,7 @@ int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);

 /*
 ** CAPI3REF: Low-level system error code
+** METHOD: sqlite3
 **
 ** ^Attempt to return the underlying operating system error code or error
 ** number that caused the most recent I/O error or failure to open a file.
@@ -335,6 +335,8 @@ struct sqlite3_api_routines {
                           int,const char**);
  void (*free_filename)(char*);
  sqlite3_file *(*database_file_object)(const char*);
+  /* Version 3.34.0 and later */
+  int (*txn_state)(sqlite3*,const char*);
 };

 /*
@@ -639,6 +641,8 @@ typedef int (*sqlite3_loadext_entry)(
 #define sqlite3_create_filename        sqlite3_api->create_filename
 #define sqlite3_free_filename          sqlite3_api->free_filename
 #define sqlite3_database_file_object   sqlite3_api->database_file_object
+/* Version 3.34.0 and later */
+#define sqlite3_txn_state              sqlite3_api->txn_state
 #endif /* !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION) */

 #if !defined(SQLITE_CORE) && !defined(SQLITE_OMIT_LOAD_EXTENSION)
@@ -128,6 +128,15 @@
 # define _BSD_SOURCE
 #endif

+/*
+** Macro to disable warnings about missing "break" at the end of a "case".
+*/
+#if GCC_VERSION>=7000000
+# define deliberate_fall_through __attribute__((fallthrough));
+#else
+# define deliberate_fall_through
+#endif
+
 /*
 ** For MinGW, check to see if we can include the header file containing its
 ** version information, among other things.  Normally, this internal MinGW
@@ -983,7 +992,7 @@ typedef INT16_TYPE LogEst;
 #if defined(SQLITE_ENABLE_SELECTTRACE)
 # define SELECTTRACE_ENABLED 1
 # define SELECTTRACE(K,P,S,X)  \
-  if(sqlite3SelectTrace&(K))   \
+  if(sqlite3_unsupported_selecttrace&(K))   \
    sqlite3DebugPrintf("%u/%d/%p: ",(S)->selId,(P)->addrExplain,(S)),\
    sqlite3DebugPrintf X
 #else
@@ -1046,7 +1055,7 @@ struct BusyHandler {
 ** pointer will work here as long as it is distinct from SQLITE_STATIC
 ** and SQLITE_TRANSIENT.
 */
-#define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3MallocSize)
+#define SQLITE_DYNAMIC   ((sqlite3_destructor_type)sqlite3OomFault)

 /*
 ** When SQLITE_OMIT_WSD is defined, it means that the target platform does
@@ -1497,7 +1506,10 @@ struct sqlite3 {
  int nVDestroy;                /* Number of active OP_VDestroy operations */
  int nExtension;               /* Number of loaded extensions */
  void **aExtension;            /* Array of shared library handles */
-  int (*xTrace)(u32,void*,void*,void*);     /* Trace function */
+  union {
+    void (*xLegacy)(void*,const char*);     /* Legacy trace function */
+    int (*xV2)(u32,void*,void*,void*);      /* V2 Trace function */
+  } trace;
  void *pTraceArg;                          /* Argument to the trace function */
 #ifndef SQLITE_OMIT_DEPRECATED
  void (*xProfile)(void*,const char*,u64);  /* Profiling function */
@@ -2175,6 +2187,7 @@ struct Table {
 #define TF_OOOHidden       0x0400    /* Out-of-Order hidden columns */
 #define TF_HasNotNull      0x0800    /* Contains NOT NULL constraints */
 #define TF_Shadow          0x1000    /* True for a shadow table */
+#define TF_HasStat4        0x2000    /* STAT4 info available for this table */

 /*
 ** Test to see whether or not a table is a virtual table.  This is
@@ -2540,11 +2553,6 @@ struct AggInfo {
  AggInfo *pNext;         /* Next in list of them all */
 };

-/*
-** Value for AggInfo.iAggMagic when the structure is valid
-*/
-#define AggInfoMagic  0x2059e99e
-
 /*
 ** The datatype ynVar is a signed integer, either 16-bit or 32-bit.
 ** Usually it is 16-bits.  But if SQLITE_MAX_VARIABLE_NUMBER is greater
@@ -2708,7 +2716,7 @@ struct Expr {
 #define EP_TokenOnly  0x004000 /* Expr struct EXPR_TOKENONLYSIZE bytes only */
 #define EP_Win        0x008000 /* Contains window functions */
 #define EP_MemToken   0x010000 /* Need to sqlite3DbFree() Expr.zToken */
-                  /*  0x020000 // available for reuse */
+#define EP_IfNullRow  0x020000 /* The TK_IF_NULL_ROW opcode */
 #define EP_Unlikely   0x040000 /* unlikely() or likelihood() function */
 #define EP_ConstFunc  0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
 #define EP_CanBeNull  0x100000 /* Can be null despite NOT NULL constraint */
@@ -2946,9 +2954,9 @@ struct SrcList {
 #define WHERE_DISTINCTBY       0x0080 /* pOrderby is really a DISTINCT clause */
 #define WHERE_WANT_DISTINCT    0x0100 /* All output needs to be distinct */
 #define WHERE_SORTBYGROUP      0x0200 /* Support sqlite3WhereIsSorted() */
-#define WHERE_SEEK_TABLE       0x0400 /* Do not defer seeks on main table */
+                        /*     0x0400    not currently used */
 #define WHERE_ORDERBY_LIMIT    0x0800 /* ORDERBY+LIMIT on the inner loop */
-#define WHERE_SEEK_UNIQ_TABLE  0x1000 /* Do not defer seeks if unique */
+                        /*     0x1000    not currently used */
                        /*     0x2000    not currently used */
 #define WHERE_USE_LIMIT        0x4000 /* Use the LIMIT in cost estimates */
                        /*     0x8000    not currently used */
@@ -3145,9 +3153,6 @@ struct Select {
 **                     statements within triggers whose only purpose is
 **                     the side-effects of functions.
 **
-** All of the above are free to ignore their ORDER BY clause. Those that
-** follow must honor the ORDER BY clause.
-**
 **     SRT_Output      Generate a row of output (using the OP_ResultRow
 **                     opcode) for each row in the result set.
 **
@@ -3204,13 +3209,18 @@ struct Select {
 #define SRT_Except       2  /* Remove result from a UNION index */
 #define SRT_Exists       3  /* Store 1 if the result is not empty */
 #define SRT_Discard      4  /* Do not save the results anywhere */
-#define SRT_Fifo         5  /* Store result as data with an automatic rowid */
-#define SRT_DistFifo     6  /* Like SRT_Fifo, but unique results only */
+#define SRT_DistFifo     5  /* Like SRT_Fifo, but unique results only */
+#define SRT_DistQueue    6  /* Like SRT_Queue, but unique results only */
+
+/* The DISTINCT clause is ignored for all of the above.  Not that
+** IgnorableDistinct() implies IgnorableOrderby() */
+#define IgnorableDistinct(X) ((X->eDest)<=SRT_DistQueue)
+
 #define SRT_Queue        7  /* Store result in an queue */
-#define SRT_DistQueue    8  /* Like SRT_Queue, but unique results only */
+#define SRT_Fifo         8  /* Store result as data with an automatic rowid */

 /* The ORDER BY clause is ignored for all of the above */
-#define IgnorableOrderby(X) ((X->eDest)<=SRT_DistQueue)
+#define IgnorableOrderby(X) ((X->eDest)<=SRT_Fifo)

 #define SRT_Output       9  /* Output each row of result */
 #define SRT_Mem         10  /* Store result in a memory cell */
@@ -3383,9 +3393,7 @@ struct Parse {
  ynVar nVar;               /* Number of '?' variables seen in the SQL so far */
  u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */
  u8 explain;               /* True if the EXPLAIN flag is found on the query */
-#if !(defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_OMIT_ALTERTABLE))
  u8 eParseMode;            /* PARSE_MODE_XXX constant */
-#endif
 #ifndef SQLITE_OMIT_VIRTUALTABLE
  int nVtabLock;            /* Number of virtual tables to lock */
 #endif
@@ -4179,7 +4187,7 @@ void sqlite3StartTable(Parse*,Token*,Token*,int,int,int,int);
 void sqlite3AddColumn(Parse*,Token*,Token*);
 void sqlite3AddNotNull(Parse*, int);
 void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
-void sqlite3AddCheckConstraint(Parse*, Expr*);
+void sqlite3AddCheckConstraint(Parse*, Expr*, const char*, const char*);
 void sqlite3AddDefaultValue(Parse*,Expr*,const char*,const char*);
 void sqlite3AddCollateType(Parse*, Token*);
 void sqlite3AddGenerated(Parse*,Expr*,Token*);
@@ -4586,7 +4594,7 @@ extern const unsigned char sqlite3UpperToLower[];
 extern const unsigned char sqlite3CtypeMap[];
 extern SQLITE_WSD struct Sqlite3Config sqlite3Config;
 extern FuncDefHash sqlite3BuiltinFunctions;
-extern u32 sqlite3SelectTrace;
+extern u32 sqlite3_unsupported_selecttrace;
 #ifndef SQLITE_OMIT_WSD
 extern int sqlite3PendingByte;
 #endif
@@ -60,11 +60,7 @@
 ** The maximum depth of an expression tree. This is limited to 
 ** some extent by SQLITE_MAX_SQL_LENGTH. But sometime you might 
 ** want to place more severe limits on the complexity of an 
-** expression.
-**
-** A value of 0 used to mean that the limit was not enforced.
-** But that is no longer true.  The limit is now strictly enforced
-** at all times.
+** expression. A value of 0 means that there is no limit.
 */
 #ifndef SQLITE_MAX_EXPR_DEPTH
 # define SQLITE_MAX_EXPR_DEPTH 1000
@@ -352,7 +352,7 @@ int sqlite3_db_status(
    */
    case SQLITE_DBSTATUS_CACHE_SPILL:
      op = SQLITE_DBSTATUS_CACHE_WRITE+1;
-      /* Fall through into the next case */
+      /* no break */ deliberate_fall_through
    case SQLITE_DBSTATUS_CACHE_HIT:
    case SQLITE_DBSTATUS_CACHE_MISS:
    case SQLITE_DBSTATUS_CACHE_WRITE:{
@@ -3940,7 +3940,7 @@ static int SQLITE_TCLAPI test_bind_blob(
    char zBuf[200];
    sqlite3_snprintf(sizeof(zBuf), zBuf,
                     "cannot use %d blob bytes, have %d", bytes, len);
-    Tcl_AppendResult(interp, zBuf, -1);
+    Tcl_AppendResult(interp, zBuf, (char*)0);
    return TCL_ERROR;
  }

@@ -3953,6 +3953,195 @@ static int SQLITE_TCLAPI test_bind_blob(
  return TCL_OK;
 }

+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** sqlite3_carray_bind [options...] STMT NAME VALUE ...
+**
+** Options:
+**    -transient
+**    -static
+**    -int32
+**    -int64
+**    -double
+**    -text
+**
+** Each call clears static data.  Called with no options does nothing
+** but clear static data.
+*/
+static int SQLITE_TCLAPI test_carray_bind(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3_stmt *pStmt;
+  int eType = 0;   /* CARRAY_INT32 */
+  int nData = 0;
+  void *aData = 0;
+  int isTransient = 0;
+  int isStatic = 0;
+  int idx;
+  int i, j;
+  int rc;
+  void (*xDel)(void*) = sqlite3_free;
+  static void *aStaticData = 0;
+  static int nStaticData = 0;
+  static int eStaticType = 0;
+  extern int sqlite3_carray_bind(
+    sqlite3_stmt *pStmt,
+    int i,
+    void *aData,
+    int nData,
+    int mFlags,
+    void (*xDestroy)(void*)
+  );
+  
+  if( aStaticData ){
+    /* Always clear preexisting static data on every call */
+    if( eStaticType==3 ){
+      for(i=0; i<nStaticData; i++){
+        sqlite3_free(((char**)aStaticData)[i]);
+      }
+    }
+    sqlite3_free(aStaticData);
+    aStaticData = 0;
+    nStaticData = 0;
+    eStaticType = 0;
+  }
+  if( objc==1 ) return TCL_OK;
+
+  for(i=1; i<objc && Tcl_GetString(objv[i])[0]=='-'; i++){
+    const char *z = Tcl_GetString(objv[i]);
+    if( strcmp(z, "-transient")==0 ){
+      isTransient = 1;
+      xDel = SQLITE_TRANSIENT;
+    }else
+    if( strcmp(z, "-static")==0 ){
+      isStatic = 1;
+      xDel = SQLITE_STATIC;
+    }else
+    if( strcmp(z, "-int32")==0 ){
+      eType = 0;  /* CARRAY_INT32 */
+    }else
+    if( strcmp(z, "-int64")==0 ){
+      eType = 1;  /* CARRAY_INT64 */
+    }else
+    if( strcmp(z, "-double")==0 ){
+      eType = 2;  /* CARRAY_DOUBLE */
+    }else
+    if( strcmp(z, "-text")==0 ){
+      eType = 3;  /* CARRAY_TEXT */
+    }else
+    if( strcmp(z, "--")==0 ){
+      break;
+    }else
+    {
+      Tcl_AppendResult(interp, "unknown option: ", z, (char*)0);
+      return TCL_ERROR;
+    }
+  }
+  if( eType==3 && !isStatic && !isTransient ){
+    Tcl_AppendResult(interp, "text data must be either -static or -transient",
+                     (char*)0);
+    return TCL_ERROR;
+  }
+  if( isStatic && isTransient ){
+    Tcl_AppendResult(interp, "cannot be both -static and -transient",
+                     (char*)0);
+    return TCL_ERROR;
+  }
+  if( objc-i < 2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "[OPTIONS] STMT IDX VALUE ...");
+    return TCL_ERROR;
+  }
+  if( getStmtPointer(interp, Tcl_GetString(objv[i]), &pStmt) ) return TCL_ERROR;
+  i++;
+  if( Tcl_GetIntFromObj(interp, objv[i], &idx) ) return TCL_ERROR;
+  i++;
+  nData = objc - i;
+  switch( eType + 4*(nData<=0) ){
+    case 0: { /* INT32 */
+      int *a = sqlite3_malloc( sizeof(int)*nData );
+      if( a==0 ){ rc = SQLITE_NOMEM; goto carray_bind_done; }
+      for(j=0; j<nData; j++){
+        int v;
+        if( Tcl_GetIntFromObj(interp, objv[i+j], &v) ){
+          sqlite3_free(a);
+          return TCL_ERROR;
+        }
+        a[j] = v;
+      }
+      aData = a;
+      break;
+    }
+    case 1: { /* INT64 */
+      sqlite3_int64 *a = sqlite3_malloc( sizeof(sqlite3_int64)*nData );
+      if( a==0 ){ rc = SQLITE_NOMEM; goto carray_bind_done; }
+      for(j=0; j<nData; j++){
+        Tcl_WideInt v;
+        if( Tcl_GetWideIntFromObj(interp, objv[i+j], &v) ){
+          sqlite3_free(a);
+          return TCL_ERROR;
+        }
+        a[j] = v;
+      }
+      aData = a;
+      break;
+    }
+    case 2: { /* DOUBLE */
+      double *a = sqlite3_malloc( sizeof(double)*nData );
+      if( a==0 ){ rc = SQLITE_NOMEM; goto carray_bind_done; }
+      for(j=0; j<nData; j++){
+        double v;
+        if( Tcl_GetDoubleFromObj(interp, objv[i+j], &v) ){
+          sqlite3_free(a);
+          return TCL_ERROR;
+        }
+        a[j] = v;
+      }
+      aData = a;
+      break;
+    }
+    case 3: { /* TEXT */
+      char **a = sqlite3_malloc( sizeof(char*)*nData );
+      if( a==0 ){ rc = SQLITE_NOMEM; goto carray_bind_done; }
+      for(j=0; j<nData; j++){
+        const char *v = Tcl_GetString(objv[i+j]);
+        a[j] = sqlite3_mprintf("%s", v);
+      }
+      aData = a;
+      break;
+    }
+    case 4: { /* nData==0 */
+      aData = "";
+      xDel = SQLITE_STATIC;
+      isTransient = 0;
+      isStatic = 0;
+      break;
+    }
+  }
+  if( isStatic ){
+    aStaticData = aData;
+    nStaticData = nData;
+    eStaticType = eType;
+  }
+  rc = sqlite3_carray_bind(pStmt, idx, aData, nData, eType, xDel);
+  if( isTransient ){
+    if( eType==3 ){
+      for(i=0; i<nData; i++) sqlite3_free(((char**)aData)[i]);
+    }
+    sqlite3_free(aData);
+  }
+carray_bind_done:
+  if( rc ){
+    Tcl_AppendResult(interp, sqlite3_errstr(rc), (char*)0);
+    return TCL_ERROR;
+  }
+  return TCL_OK;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
 /*
 ** Usage:   sqlite3_bind_parameter_count  STMT
 **
@@ -6239,6 +6428,36 @@ static int SQLITE_TCLAPI file_control_vfsname(
  return TCL_OK;  
 }

+/*
+** tclcmd:   file_control_reservebytes DB N
+*/
+static int SQLITE_TCLAPI file_control_reservebytes(
+  ClientData clientData, /* Pointer to sqlite3_enable_XXX function */
+  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
+  int objc,              /* Number of arguments */
+  Tcl_Obj *CONST objv[]  /* Command arguments */
+){
+  sqlite3 *db;
+  const char *zDbName = "main";
+  int n = 0;
+  int rc;
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB N");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db)
+   || Tcl_GetIntFromObj(interp, objv[2], &n) 
+  ){
+    return TCL_ERROR;
+  }
+
+  rc = sqlite3_file_control(db, zDbName, SQLITE_FCNTL_RESERVE_BYTES, (void*)&n);
+  Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+  return TCL_OK;  
+}
+
+
 /*
 ** tclcmd:   file_control_tempfilename DB ?AUXDB?
 **
@@ -7749,6 +7968,33 @@ static int SQLITE_TCLAPI test_sqlite3_db_config(
  Tcl_SetObjResult(interp, Tcl_NewIntObj(v));
  return TCL_OK;
 }
+/*
+** tclcmd:   sqlite3_txn_state DB ?SCHEMA?
+**
+** Invoke sqlite3_txn_state(DB,SCHEMA) and return the
+** numeric value that results.  Use NULL for SCHEMA if the 3 argument
+** is omitted.
+*/
+static int SQLITE_TCLAPI test_sqlite3_txn_state(
+  void *clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  const char *zSchema;
+  int iTxn;
+
+  if( objc!=2 && objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB ?SCHEMA?");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  zSchema = objc==3 ? Tcl_GetString(objv[2]) : 0;
+  iTxn = sqlite3_txn_state(db, zSchema);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(iTxn));
+  return TCL_OK;
+}

 /*
 ** Change the name of the main database schema from "main" to "icecube".
@@ -7802,6 +8048,83 @@ static int SQLITE_TCLAPI test_mmap_warm(
  }
 }

+/*
+** Usage:  test_write_db DB OFFSET DATA
+**
+** Obtain the sqlite3_file* object for the database file for the "main" db
+** of handle DB. Then invoke its xWrite method to write data DATA to offset
+** OFFSET.
+*/
+static int SQLITE_TCLAPI test_write_db(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db = 0;
+  Tcl_WideInt iOff = 0;
+  const unsigned char *aData = 0;
+  int nData = 0;
+  sqlite3_file *pFile = 0;
+  int rc;
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB OFFSET DATA");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  if( Tcl_GetWideIntFromObj(interp, objv[2], &iOff) ) return TCL_ERROR;
+  aData = Tcl_GetByteArrayFromObj(objv[3], &nData);
+
+  sqlite3_file_control(db, "main", SQLITE_FCNTL_FILE_POINTER, (void*)&pFile);
+  rc = pFile->pMethods->xWrite(pFile, aData, nData, iOff);
+
+  Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_register_cksumvfs
+**
+*/
+static int SQLITE_TCLAPI test_register_cksumvfs(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }else{
+    extern int sqlite3_register_cksumvfs(const char*);
+    int rc = sqlite3_register_cksumvfs(0);
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
+  }
+  return TCL_OK;
+}
+
+/*
+** Usage:  sqlite3_unregister_cksumvfs
+**
+*/
+static int SQLITE_TCLAPI test_unregister_cksumvfs(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  if( objc!=1 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "");
+    return TCL_ERROR;
+  }else{
+    extern int sqlite3_unregister_cksumvfs(void);
+    int rc = sqlite3_unregister_cksumvfs();
+    Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_VOLATILE);
+  }
+  return TCL_OK;
+}
+
 /*
 ** Usage:  decode_hexdb TEXT
 **
@@ -7950,6 +8273,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
     void *clientData;
  } aObjCmd[] = {
     { "sqlite3_db_config",             test_sqlite3_db_config, 0 },
+     { "sqlite3_txn_state",             test_sqlite3_txn_state, 0 },
     { "bad_behavior",                  test_bad_behavior,  (void*)&iZero },
     { "register_dbstat_vtab",          test_register_dbstat_vtab  },
     { "sqlite3_connection_pointer",    get_sqlite_pointer, 0 },
@@ -7966,6 +8290,9 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
     { "sqlite3_bind_text",             test_bind_text     ,0 },
     { "sqlite3_bind_text16",           test_bind_text16   ,0 },
     { "sqlite3_bind_blob",             test_bind_blob     ,0 },
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+     { "sqlite3_carray_bind",           test_carray_bind   ,0 },
+#endif
     { "sqlite3_bind_parameter_count",  test_bind_parameter_count, 0},
     { "sqlite3_bind_parameter_name",   test_bind_parameter_name,  0},
     { "sqlite3_bind_parameter_index",  test_bind_parameter_index, 0},
@@ -8097,6 +8424,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
     { "file_control_persist_wal",    file_control_persist_wal,     0   },
     { "file_control_powersafe_overwrite",file_control_powersafe_overwrite,0},
     { "file_control_vfsname",        file_control_vfsname,         0   },
+     { "file_control_reservebytes",   file_control_reservebytes,    0   },
     { "file_control_tempfilename",   file_control_tempfilename,    0   },
     { "sqlite3_vfs_list",           vfs_list,     0   },
     { "sqlite3_create_function_v2", test_create_function_v2, 0 },
@@ -8166,6 +8494,9 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
     { "sqlite3_mmap_warm",       test_mmap_warm,          0 },
     { "sqlite3_config_sorterref", test_config_sorterref,   0 },
     { "decode_hexdb",             test_decode_hexdb,       0 },
+     { "test_write_db",            test_write_db,           0 },
+     { "sqlite3_register_cksumvfs", test_register_cksumvfs,  0 },
+     { "sqlite3_unregister_cksumvfs", test_unregister_cksumvfs,  0 },
  };
  static int bitmask_size = sizeof(Bitmask)*8;
  static int longdouble_size = sizeof(LONGDOUBLE_TYPE);
@@ -8191,7 +8522,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
 #endif
 #endif
 #if defined(SQLITE_ENABLE_SELECTTRACE)
-  extern u32 sqlite3SelectTrace;
+  extern u32 sqlite3_unsupported_selecttrace;
 #endif

  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
@@ -8279,8 +8610,8 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
  Tcl_LinkVar(interp, "sqlite_fullsync_count",
      (char*)&sqlite3_fullsync_count, TCL_LINK_INT);
 #if defined(SQLITE_ENABLE_SELECTTRACE)
-  Tcl_LinkVar(interp, "sqlite3SelectTrace",
-      (char*)&sqlite3SelectTrace, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite3_unsupported_selecttrace",
+      (char*)&sqlite3_unsupported_selecttrace, TCL_LINK_INT);
 #endif
 #if defined(SQLITE_ENABLE_FTS3) && defined(SQLITE_TEST)
  Tcl_LinkVar(interp, "sqlite_fts3_enable_parentheses",
@@ -550,13 +550,16 @@ static int cfDeviceCharacteristics(sqlite3_file *pFile){
 ** Pass-throughs for WAL support.
 */
 static int cfShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
-  return sqlite3OsShmLock(((CrashFile*)pFile)->pRealFile, ofst, n, flags);
+  sqlite3_file *pReal = ((CrashFile*)pFile)->pRealFile;
+  return pReal->pMethods->xShmLock(pReal, ofst, n, flags);
 }
 static void cfShmBarrier(sqlite3_file *pFile){
-  sqlite3OsShmBarrier(((CrashFile*)pFile)->pRealFile);
+  sqlite3_file *pReal = ((CrashFile*)pFile)->pRealFile;
+  pReal->pMethods->xShmBarrier(pReal);
 }
 static int cfShmUnmap(sqlite3_file *pFile, int delFlag){
-  return sqlite3OsShmUnmap(((CrashFile*)pFile)->pRealFile, delFlag);
+  sqlite3_file *pReal = ((CrashFile*)pFile)->pRealFile;
+  return pReal->pMethods->xShmUnmap(pReal, delFlag);
 }
 static int cfShmMap(
  sqlite3_file *pFile,            /* Handle open on database file */
@@ -565,7 +568,8 @@ static int cfShmMap(
  int w,                          /* True to extend file if necessary */
  void volatile **pp              /* OUT: Mapped memory */
 ){
-  return sqlite3OsShmMap(((CrashFile*)pFile)->pRealFile, iRegion, sz, w, pp);
+  sqlite3_file *pReal = ((CrashFile*)pFile)->pRealFile;
+  return pReal->pMethods->xShmMap(pReal, iRegion, sz, w, pp);
 }

 static const sqlite3_io_methods CrashFileVtab = {
@@ -191,7 +191,7 @@ static int devsymDeviceCharacteristics(sqlite3_file *pFile){
 */
 static int devsymShmLock(sqlite3_file *pFile, int ofst, int n, int flags){
  devsym_file *p = (devsym_file *)pFile;
-  return sqlite3OsShmLock(p->pReal, ofst, n, flags);
+  return p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags);
 }
 static int devsymShmMap(
  sqlite3_file *pFile, 
@@ -201,15 +201,15 @@ static int devsymShmMap(
  void volatile **pp
 ){
  devsym_file *p = (devsym_file *)pFile;
-  return sqlite3OsShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
+  return p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
 }
 static void devsymShmBarrier(sqlite3_file *pFile){
  devsym_file *p = (devsym_file *)pFile;
-  sqlite3OsShmBarrier(p->pReal);
+  p->pReal->pMethods->xShmBarrier(p->pReal);
 }
 static int devsymShmUnmap(sqlite3_file *pFile, int delFlag){
  devsym_file *p = (devsym_file *)pFile;
-  return sqlite3OsShmUnmap(p->pReal, delFlag);
+  return p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
 }


@@ -168,7 +168,7 @@ static int SQLITE_TCLAPI hexio_write(
  if( Tcl_GetIntFromObj(interp, objv[2], &offset) ) return TCL_ERROR;
  zFile = Tcl_GetString(objv[1]);
  zIn = (const unsigned char *)Tcl_GetStringFromObj(objv[3], &nIn);
-  aOut = sqlite3_malloc( nIn/2 );
+  aOut = sqlite3_malloc( 1 + nIn/2 );
  if( aOut==0 ){
    return TCL_ERROR;
  }
@@ -213,7 +213,7 @@ static int SQLITE_TCLAPI hexio_get_int(
    return TCL_ERROR;
  }
  zIn = (const unsigned char *)Tcl_GetStringFromObj(objv[1], &nIn);
-  aOut = sqlite3_malloc( nIn/2 );
+  aOut = sqlite3_malloc( 1 + nIn/2 );
  if( aOut==0 ){
    return TCL_ERROR;
  }
@@ -309,7 +309,7 @@ static int SQLITE_TCLAPI utf8_to_utf8(
    return TCL_ERROR;
  }
  zOrig = (unsigned char *)Tcl_GetStringFromObj(objv[1], &n);
-  z = sqlite3_malloc( n+3 );
+  z = sqlite3_malloc( n+4 );
  n = sqlite3TestHexToBin(zOrig, n, z);
  z[n] = 0;
  nOut = sqlite3Utf8To8(z);
@@ -895,7 +895,8 @@ static int tvfsShmMap(
  Testvfs *p = (Testvfs *)(pFd->pVfs->pAppData);

  if( p->isFullshm ){
-    return sqlite3OsShmMap(pFd->pReal, iPage, pgsz, isWrite, pp);
+    sqlite3_file *pReal = pFd->pReal;
+    return pReal->pMethods->xShmMap(pReal, iPage, pgsz, isWrite, pp);
  }

  if( 0==pFd->pShm ){
@@ -945,7 +946,8 @@ static int tvfsShmLock(
  char zLock[80];

  if( p->isFullshm ){
-    return sqlite3OsShmLock(pFd->pReal, ofst, n, flags);
+    sqlite3_file *pReal = pFd->pReal;
+    return pReal->pMethods->xShmLock(pReal, ofst, n, flags);
  }

  if( p->pScript && p->mask&TESTVFS_SHMLOCK_MASK ){
@@ -1009,7 +1011,8 @@ static void tvfsShmBarrier(sqlite3_file *pFile){
  }

  if( p->isFullshm ){
-    sqlite3OsShmBarrier(pFd->pReal);
+    sqlite3_file *pReal = pFd->pReal;
+    pReal->pMethods->xShmBarrier(pReal);
    return;
  }
 }
@@ -1025,7 +1028,8 @@ static int tvfsShmUnmap(
  TestvfsFd **ppFd;

  if( p->isFullshm ){
-    return sqlite3OsShmUnmap(pFd->pReal, deleteFlag);
+    sqlite3_file *pReal = pFd->pReal;
+    return pReal->pMethods->xShmUnmap(pReal, deleteFlag);
  }

  if( !pBuffer ) return SQLITE_OK;
@@ -422,6 +422,7 @@ 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: {
      testcase( z[0]=='0' );  testcase( z[0]=='1' );  testcase( z[0]=='2' );
@@ -526,6 +527,7 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
 #endif
      /* 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;
@@ -157,22 +157,11 @@ void sqlite3BeginTrigger(
  pTab = sqlite3SrcListLookup(pParse, pTableName);
  if( !pTab ){
    /* The table does not exist. */
-    if( db->init.iDb==1 ){
-      /* Ticket #3810.
-      ** Normally, whenever a table is dropped, all associated triggers are
-      ** dropped too.  But if a TEMP trigger is created on a non-TEMP table
-      ** and the table is dropped by a different database connection, the
-      ** trigger is not visible to the database connection that does the
-      ** drop so the trigger cannot be dropped.  This results in an
-      ** "orphaned trigger" - a trigger whose associated table is missing.
-      */
-      db->init.orphanTrigger = 1;
-    }
-    goto trigger_cleanup;
+    goto trigger_orphan_error;
  }
  if( IsVirtual(pTab) ){
    sqlite3ErrorMsg(pParse, "cannot create triggers on virtual tables");
-    goto trigger_cleanup;
+    goto trigger_orphan_error;
  }

  /* Check that the trigger name is not reserved and that no trigger of the
@@ -210,12 +199,12 @@ void sqlite3BeginTrigger(
  if( pTab->pSelect && tr_tm!=TK_INSTEAD ){
    sqlite3ErrorMsg(pParse, "cannot create %s trigger on view: %S", 
        (tr_tm == TK_BEFORE)?"BEFORE":"AFTER", pTableName, 0);
-    goto trigger_cleanup;
+    goto trigger_orphan_error;
  }
  if( !pTab->pSelect && tr_tm==TK_INSTEAD ){
    sqlite3ErrorMsg(pParse, "cannot create INSTEAD OF"
        " trigger on table: %S", pTableName, 0);
-    goto trigger_cleanup;
+    goto trigger_orphan_error;
  }

 #ifndef SQLITE_OMIT_AUTHORIZATION
@@ -275,6 +264,23 @@ trigger_cleanup:
  }else{
    assert( pParse->pNewTrigger==pTrigger );
  }
+  return;
+
+trigger_orphan_error:
+  if( db->init.iDb==1 ){
+    /* Ticket #3810.
+    ** Normally, whenever a table is dropped, all associated triggers are
+    ** dropped too.  But if a TEMP trigger is created on a non-TEMP table
+    ** and the table is dropped by a different database connection, the
+    ** trigger is not visible to the database connection that does the
+    ** drop so the trigger cannot be dropped.  This results in an
+    ** "orphaned trigger" - a trigger whose associated table is missing.
+    **
+    ** 2020-11-05 see also https://sqlite.org/forum/forumpost/157dc791df
+    */
+    db->init.orphanTrigger = 1;
+  }
+  goto trigger_cleanup;
 }

 /*
@@ -234,7 +234,7 @@ static void updateFromSelect(
 #endif
      pList = sqlite3ExprListAppend(pParse, pList, pNew);
    }
-    eDest = SRT_Upfrom;
+    eDest = IsVirtual(pTab) ? SRT_Table : SRT_Upfrom;
  }else if( pTab->pSelect ){
    for(i=0; i<pTab->nCol; i++){
      pList = sqlite3ExprListAppend(pParse, pList, exprRowColumn(pParse, i));
@@ -651,6 +651,8 @@ void sqlite3Update(

  if( nChangeFrom==0 && HasRowid(pTab) ){
    sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid);
+    iEph = pParse->nTab++;
+    addrOpen = sqlite3VdbeAddOp3(v, OP_OpenEphemeral, iEph, 0, regRowSet);
  }else{
    assert( pPk!=0 || HasRowid(pTab) );
    nPk = pPk ? pPk->nKeyCol : 0;
@@ -705,7 +707,7 @@ void sqlite3Update(
      ** be deleted as a result of REPLACE conflict handling. Any of these
      ** things might disturb a cursor being used to scan through the table
      ** or index, causing a single-pass approach to malfunction.  */
-      flags = WHERE_ONEPASS_DESIRED|WHERE_SEEK_UNIQ_TABLE;
+      flags = WHERE_ONEPASS_DESIRED;
      if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){
        flags |= WHERE_ONEPASS_MULTIROW;
      }
@@ -742,9 +744,10 @@ void sqlite3Update(
      ** leave it in register regOldRowid.  */
      sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid);
      if( eOnePass==ONEPASS_OFF ){
-        /* We need to use regRowSet, so reallocate aRegIdx[nAllIdx] */
        aRegIdx[nAllIdx] = ++pParse->nMem;
-        sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid);
+        sqlite3VdbeAddOp3(v, OP_Insert, iEph, regRowSet, regOldRowid);
+      }else{
+        if( ALWAYS(addrOpen) ) sqlite3VdbeChangeToNoop(v, addrOpen);
      }
    }else{
      /* Read the PK of the current row into an array of registers. In
@@ -832,8 +835,9 @@ void sqlite3Update(
        VdbeCoverage(v);
      }
    }else{
-      labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet,labelBreak,
-                               regOldRowid);
+      sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v);
+      labelContinue = sqlite3VdbeMakeLabel(pParse);
+      addrTop = sqlite3VdbeAddOp2(v, OP_Rowid, iEph, regOldRowid);
      VdbeCoverage(v);
      sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid);
      VdbeCoverage(v);
@@ -1083,11 +1087,9 @@ void sqlite3Update(
  }else if( eOnePass==ONEPASS_MULTI ){
    sqlite3VdbeResolveLabel(v, labelContinue);
    sqlite3WhereEnd(pWInfo);
-  }else if( pPk || nChangeFrom ){
+  }else{
    sqlite3VdbeResolveLabel(v, labelContinue);
    sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v);
-  }else{
-    sqlite3VdbeGoto(v, labelContinue);
  }
  sqlite3VdbeResolveLabel(v, labelBreak);

@@ -1187,12 +1189,26 @@ static void updateVirtualTable(
  regArg = pParse->nMem + 1;
  pParse->nMem += nArg;
  if( pSrc->nSrc>1 ){
+    Index *pPk = 0;
    Expr *pRow;
    ExprList *pList;
-    if( pRowid ){
-      pRow = sqlite3ExprDup(db, pRowid, 0);
+    if( HasRowid(pTab) ){
+      if( pRowid ){
+        pRow = sqlite3ExprDup(db, pRowid, 0);
+      }else{
+        pRow = sqlite3PExpr(pParse, TK_ROW, 0, 0);
+      }
    }else{
-      pRow = sqlite3PExpr(pParse, TK_ROW, 0, 0);
+      i16 iPk;      /* PRIMARY KEY column */
+      pPk = sqlite3PrimaryKeyIndex(pTab);
+      assert( pPk!=0 );
+      assert( pPk->nKeyCol==1 );
+      iPk = pPk->aiColumn[0];
+      if( aXRef[iPk]>=0 ){
+        pRow = sqlite3ExprDup(db, pChanges->a[aXRef[iPk]].pExpr, 0);
+      }else{
+        pRow = exprRowColumn(pParse, iPk);
+      }
    }
    pList = sqlite3ExprListAppend(pParse, 0, pRow);

@@ -1206,7 +1222,7 @@ static void updateVirtualTable(
      }
    }

-    updateFromSelect(pParse, ephemTab, 0, pList, pSrc, pWhere, 0, 0);
+    updateFromSelect(pParse, ephemTab, pPk, pList, pSrc, pWhere, 0, 0);
    sqlite3ExprListDelete(db, pList);
    eOnePass = ONEPASS_OFF;
  }else{
@@ -681,6 +681,7 @@ int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){
    incr = 1;
  }else{
    incr = 2;
+    length &= ~1;
    assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
    for(i=3-enc; i<length && zNum[i]==0; i+=2){}
    nonNum = i<length;
@@ -339,8 +339,8 @@ SQLITE_NOINLINE int sqlite3RunVacuum(
       BTREE_APPLICATION_ID,     0,  /* Preserve the application id */
    };

-    assert( 1==sqlite3BtreeIsInTrans(pTemp) );
-    assert( pOut!=0 || 1==sqlite3BtreeIsInTrans(pMain) );
+    assert( SQLITE_TXN_WRITE==sqlite3BtreeTxnState(pTemp) );
+    assert( pOut!=0 || SQLITE_TXN_WRITE==sqlite3BtreeTxnState(pMain) );

    /* Copy Btree meta values */
    for(i=0; i<ArraySize(aCopy); i+=2){
@@ -1033,6 +1033,7 @@ case OP_HaltIfNull: {      /* in3 */
 #endif
  if( (pIn3->flags & MEM_Null)==0 ) break;
  /* Fall through into OP_Halt */
+  /* no break */ deliberate_fall_through
 }

 /* Opcode:  Halt P1 P2 * P4 P5
@@ -1203,6 +1204,7 @@ case OP_String8: {         /* same as TK_STRING, out2 */
  pOp->opcode = OP_String;
  assert( rc==SQLITE_OK );
  /* Fall through to the next case, OP_String */
+  /* no break */ deliberate_fall_through
 }
  
 /* Opcode: String P1 P2 P3 P4 P5
@@ -1514,7 +1516,7 @@ case OP_ResultRow: {
  if( db->mallocFailed ) goto no_mem;

  if( db->mTrace & SQLITE_TRACE_ROW ){
-    db->xTrace(SQLITE_TRACE_ROW, db->pTraceArg, p, 0);
+    db->trace.xV2(SQLITE_TRACE_ROW, db->pTraceArg, p, 0);
  }


@@ -3485,7 +3487,8 @@ case OP_AutoCommit: {
 ** active.
 ** If P2 is non-zero, then a write-transaction is started, or if a 
 ** read-transaction is already active, it is upgraded to a write-transaction.
-** If P2 is zero, then a read-transaction is started.
+** If P2 is zero, then a read-transaction is started.  If P2 is 2 or more
+** then an exclusive transaction is started.
 **
 ** P1 is the index of the database file on which the transaction is
 ** started.  Index 0 is the main database file and index 1 is the
@@ -3519,6 +3522,7 @@ case OP_Transaction: {

  assert( p->bIsReader );
  assert( p->readOnly==0 || pOp->p2==0 );
+  assert( pOp->p2>=0 && pOp->p2<=2 );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( DbMaskTest(p->btreeMask, pOp->p1) );
  if( pOp->p2 && (db->flags & SQLITE_QueryOnly)!=0 ){
@@ -3544,7 +3548,7 @@ case OP_Transaction: {
     && pOp->p2
     && (db->autoCommit==0 || db->nVdbeRead>1) 
    ){
-      assert( sqlite3BtreeIsInTrans(pBt) );
+      assert( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE );
      if( p->iStatement==0 ){
        assert( db->nStatement>=0 && db->nSavepoint>=0 );
        db->nStatement++; 
@@ -3897,7 +3901,7 @@ case OP_OpenDup: {
 }


-/* Opcode: OpenEphemeral P1 P2 * P4 P5
+/* Opcode: OpenEphemeral P1 P2 P3 P4 P5
 ** Synopsis: nColumn=P2
 **
 ** Open a new cursor P1 to a transient table.
@@ -3917,6 +3921,10 @@ case OP_OpenDup: {
 ** in btree.h.  These flags control aspects of the operation of
 ** the btree.  The BTREE_OMIT_JOURNAL and BTREE_SINGLE flags are
 ** added automatically.
+**
+** If P3 is positive, then reg[P3] is modified slightly so that it
+** can be used as zero-length data for OP_Insert.  This is an optimization
+** that avoids an extra OP_Blob opcode to initialize that register.
 */
 /* Opcode: OpenAutoindex P1 P2 * P4 *
 ** Synopsis: nColumn=P2
@@ -3939,6 +3947,15 @@ case OP_OpenEphemeral: {
      SQLITE_OPEN_TRANSIENT_DB;
  assert( pOp->p1>=0 );
  assert( pOp->p2>=0 );
+  if( pOp->p3>0 ){
+    /* Make register reg[P3] into a value that can be used as the data
+    ** form sqlite3BtreeInsert() where the length of the data is zero. */
+    assert( pOp->p2==0 ); /* Only used when number of columns is zero */
+    assert( pOp->opcode==OP_OpenEphemeral );
+    assert( aMem[pOp->p3].flags & MEM_Null );
+    aMem[pOp->p3].n = 0;
+    aMem[pOp->p3].z = "";
+  }
  pCx = p->apCsr[pOp->p1];
  if( pCx && pCx->pBtx ){
    /* If the ephermeral table is already open, erase all existing content
@@ -4381,22 +4398,172 @@ seek_not_found:
  break;
 }

-/* Opcode: SeekHit P1 P2 * * *
-** Synopsis: seekHit=P2
+
+/* Opcode: SeekScan  P1 P2 * * *
+** Synopsis: Scan-ahead up to P1 rows
 **
-** Set the seekHit flag on cursor P1 to the value in P2.
-** The seekHit flag is used by the IfNoHope opcode.
+** This opcode is a prefix opcode to OP_SeekGE.  In other words, this
+** opcode must be immediately followed by OP_SeekGE. This constraint is
+** checked by assert() statements.
 **
-** P1 must be a valid b-tree cursor.  P2 must be a boolean value,
-** either 0 or 1.
+** This opcode uses the P1 through P4 operands of the subsequent
+** OP_SeekGE.  In the text that follows, the operands of the subsequent
+** OP_SeekGE opcode are denoted as SeekOP.P1 through SeekOP.P4.   Only
+** the P1 and P2 operands of this opcode are also used, and  are called
+** This.P1 and This.P2.
+**
+** This opcode helps to optimize IN operators on a multi-column index
+** where the IN operator is on the later terms of the index by avoiding
+** unnecessary seeks on the btree, substituting steps to the next row
+** of the b-tree instead.  A correct answer is obtained if this opcode
+** is omitted or is a no-op.
+**
+** The SeekGE.P3 and SeekGE.P4 operands identify an unpacked key which
+** is the desired entry that we want the cursor SeekGE.P1 to be pointing
+** to.  Call this SeekGE.P4/P5 row the "target".
+**
+** If the SeekGE.P1 cursor is not currently pointing to a valid row,
+** then this opcode is a no-op and control passes through into the OP_SeekGE.
+**
+** If the SeekGE.P1 cursor is pointing to a valid row, then that row
+** might be the target row, or it might be near and slightly before the
+** target row.  This opcode attempts to position the cursor on the target
+** row by, perhaps by invoking sqlite3BtreeStep() on the cursor
+** between 0 and This.P1 times.
+**
+** There are three possible outcomes from this opcode:<ol>
+**
+** <li> If after This.P1 steps, the cursor is still point to a place that
+**      is earlier in the btree than the target row,
+**      then fall through into the subsquence OP_SeekGE opcode.
+**
+** <li> If the cursor is successfully moved to the target row by 0 or more
+**      sqlite3BtreeNext() calls, then jump to This.P2, which will land just
+**      past the OP_IdxGT opcode that follows the OP_SeekGE.
+**
+** <li> If the cursor ends up past the target row (indicating the the target
+**      row does not exist in the btree) then jump to SeekOP.P2. 
+** </ol>
+*/
+case OP_SeekScan: {
+  VdbeCursor *pC;
+  int res;
+  int nStep;
+  UnpackedRecord r;
+
+  assert( pOp[1].opcode==OP_SeekGE );
+
+  /* pOp->p2 points to the first instruction past the OP_IdxGT that
+  ** follows the OP_SeekGE.  */
+  assert( pOp->p2>=(int)(pOp-aOp)+2 );
+  assert( aOp[pOp->p2-1].opcode==OP_IdxGT );
+  assert( pOp[1].p1==aOp[pOp->p2-1].p1 );
+  assert( pOp[1].p2==aOp[pOp->p2-1].p2 );
+  assert( pOp[1].p3==aOp[pOp->p2-1].p3 );
+
+  assert( pOp->p1>0 );
+  pC = p->apCsr[pOp[1].p1];
+  assert( pC!=0 );
+  assert( pC->eCurType==CURTYPE_BTREE );
+  assert( !pC->isTable );
+  if( !sqlite3BtreeCursorIsValidNN(pC->uc.pCursor) ){
+#ifdef SQLITE_DEBUG
+     if( db->flags&SQLITE_VdbeTrace ){
+       printf("... cursor not valid - fall through\n");
+     }        
+#endif
+    break;
+  }
+  nStep = pOp->p1;
+  assert( nStep>=1 );
+  r.pKeyInfo = pC->pKeyInfo;
+  r.nField = (u16)pOp[1].p4.i;
+  r.default_rc = 0;
+  r.aMem = &aMem[pOp[1].p3];
+#ifdef SQLITE_DEBUG
+  {
+    int i;
+    for(i=0; i<r.nField; i++){
+      assert( memIsValid(&r.aMem[i]) );
+      REGISTER_TRACE(pOp[1].p3+i, &aMem[pOp[1].p3+i]);
+    }
+  }
+#endif
+  res = 0;  /* Not needed.  Only used to silence a warning. */
+  while(1){
+    rc = sqlite3VdbeIdxKeyCompare(db, pC, &r, &res);
+    if( rc ) goto abort_due_to_error;
+    if( res>0 ){
+      seekscan_search_fail:
+#ifdef SQLITE_DEBUG
+      if( db->flags&SQLITE_VdbeTrace ){
+        printf("... %d steps and then skip\n", pOp->p1 - nStep);
+      }        
+#endif
+      VdbeBranchTaken(1,3);
+      pOp++;
+      goto jump_to_p2;
+    }
+    if( res==0 ){
+#ifdef SQLITE_DEBUG
+      if( db->flags&SQLITE_VdbeTrace ){
+        printf("... %d steps and then success\n", pOp->p1 - nStep);
+      }        
+#endif
+      VdbeBranchTaken(2,3);
+      goto jump_to_p2;
+      break;
+    }
+    if( nStep<=0 ){
+#ifdef SQLITE_DEBUG
+      if( db->flags&SQLITE_VdbeTrace ){
+        printf("... fall through after %d steps\n", pOp->p1);
+      }        
+#endif
+      VdbeBranchTaken(0,3);
+      break;
+    }
+    nStep--;
+    rc = sqlite3BtreeNext(pC->uc.pCursor, 0);
+    if( rc ){
+      if( rc==SQLITE_DONE ){
+        rc = SQLITE_OK;
+        goto seekscan_search_fail;
+      }else{
+        goto abort_due_to_error;
+      }
+    }
+  }
+  
+  break;
+}
+
+
+/* Opcode: SeekHit P1 P2 P3 * *
+** Synopsis: set P2<=seekHit<=P3
+**
+** Increase or decrease the seekHit value for cursor P1, if necessary,
+** so that it is no less than P2 and no greater than P3.
+**
+** The seekHit integer represents the maximum of terms in an index for which
+** there is known to be at least one match.  If the seekHit value is smaller
+** than the total number of equality terms in an index lookup, then the
+** OP_IfNoHope opcode might run to see if the IN loop can be abandoned
+** early, thus saving work.  This is part of the IN-early-out optimization.
+**
+** P1 must be a valid b-tree cursor.
 */
 case OP_SeekHit: {
  VdbeCursor *pC;
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
-  assert( pOp->p2==0 || pOp->p2==1 );
-  pC->seekHit = pOp->p2 & 1;
+  assert( pOp->p3>=pOp->p2 );
+  if( pC->seekHit<pOp->p2 ){
+    pC->seekHit = pOp->p2;
+  }else if( pC->seekHit>pOp->p3 ){
+    pC->seekHit = pOp->p3;
+  }
  break;
 }

@@ -4454,16 +4621,20 @@ case OP_IfNotOpen: {        /* jump */
 ** Synopsis: key=r[P3@P4]
 **
 ** Register P3 is the first of P4 registers that form an unpacked
-** record.
+** record.  Cursor P1 is an index btree.  P2 is a jump destination.
+** In other words, the operands to this opcode are the same as the
+** operands to OP_NotFound and OP_IdxGT.
 **
-** Cursor P1 is on an index btree.  If the seekHit flag is set on P1, then
-** this opcode is a no-op.  But if the seekHit flag of P1 is clear, then
-** check to see if there is any entry in P1 that matches the
-** prefix identified by P3 and P4.  If no entry matches the prefix,
-** jump to P2.  Otherwise fall through.
+** This opcode is an optimization attempt only.  If this opcode always
+** falls through, the correct answer is still obtained, but extra works
+** is performed.
 **
-** This opcode behaves like OP_NotFound if the seekHit
-** flag is clear and it behaves like OP_Noop if the seekHit flag is set.
+** A value of N in the seekHit flag of cursor P1 means that there exists
+** a key P3:N that will match some record in the index.  We want to know
+** if it is possible for a record P3:P4 to match some record in the
+** index.  If it is not possible, we can skips some work.  So if seekHit
+** is less than P4, attempt to find out if a match is possible by running
+** OP_NotFound.
 **
 ** This opcode is used in IN clause processing for a multi-column key.
 ** If an IN clause is attached to an element of the key other than the
@@ -4505,8 +4676,9 @@ case OP_IfNoHope: {     /* jump, in3 */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
-  if( pC->seekHit ) break;
+  if( pC->seekHit>=pOp->p4.i ) break;
  /* Fall through into OP_NotFound */
+  /* no break */ deliberate_fall_through
 }
 case OP_NoConflict:     /* jump, in3 */
 case OP_NotFound:       /* jump, in3 */
@@ -4586,6 +4758,7 @@ case OP_Found: {        /* jump, in3 */
  }else{
    VdbeBranchTaken(takeJump||alreadyExists==0,2);
    if( takeJump || !alreadyExists ) goto jump_to_p2;
+    if( pOp->opcode==OP_IfNoHope ) pC->seekHit = pOp->p4.i;
  }
  break;
 }
@@ -4661,6 +4834,7 @@ case OP_SeekRowid: {        /* jump, in3 */
    goto notExistsWithKey;
  }
  /* Fall through into OP_NotExists */
+  /* no break */ deliberate_fall_through
 case OP_NotExists:          /* jump, in3 */
  pIn3 = &aMem[pOp->p3];
  assert( (pIn3->flags & MEM_Int)!=0 || pOp->opcode==OP_SeekRowid );
@@ -4941,7 +5115,7 @@ case OP_Insert: {

  if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
  if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = x.nKey;
-  assert( pData->flags & (MEM_Blob|MEM_Str) );
+  assert( (pData->flags & (MEM_Blob|MEM_Str))!=0 || pData->n==0 );
  x.pData = pData->z;
  x.nData = pData->n;
  seekResult = ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0);
@@ -5432,6 +5606,7 @@ case OP_Sort: {        /* jump */
 #endif
  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
  /* Fall through into OP_Rewind */
+  /* no break */ deliberate_fall_through
 }
 /* Opcode: Rewind P1 P2 * * *
 **
@@ -5816,7 +5991,7 @@ case OP_FinishSeek: {
  break;
 }

-/* Opcode: IdxGE P1 P2 P3 P4 P5
+/* Opcode: IdxGE P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
 ** The P4 register values beginning with P3 form an unpacked index 
@@ -5827,7 +6002,7 @@ case OP_FinishSeek: {
 ** If the P1 index entry is greater than or equal to the key value
 ** then jump to P2.  Otherwise fall through to the next instruction.
 */
-/* Opcode: IdxGT P1 P2 P3 P4 P5
+/* Opcode: IdxGT P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
 ** The P4 register values beginning with P3 form an unpacked index 
@@ -5838,7 +6013,7 @@ case OP_FinishSeek: {
 ** If the P1 index entry is greater than the key value
 ** then jump to P2.  Otherwise fall through to the next instruction.
 */
-/* Opcode: IdxLT P1 P2 P3 P4 P5
+/* Opcode: IdxLT P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
 ** The P4 register values beginning with P3 form an unpacked index 
@@ -5849,7 +6024,7 @@ case OP_FinishSeek: {
 ** If the P1 index entry is less than the key value then jump to P2.
 ** Otherwise fall through to the next instruction.
 */
-/* Opcode: IdxLE P1 P2 P3 P4 P5
+/* Opcode: IdxLE P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
 ** The P4 register values beginning with P3 form an unpacked index 
@@ -5875,7 +6050,6 @@ case OP_IdxGE:  {       /* jump */
  assert( pC->eCurType==CURTYPE_BTREE );
  assert( pC->uc.pCursor!=0);
  assert( pC->deferredMoveto==0 );
-  assert( pOp->p5==0 || pOp->p5==1 );
  assert( pOp->p4type==P4_INT32 );
  r.pKeyInfo = pC->pKeyInfo;
  r.nField = (u16)pOp->p4.i;
@@ -5896,8 +6070,31 @@ case OP_IdxGE:  {       /* jump */
    }
  }
 #endif
-  res = 0;  /* Not needed.  Only used to silence a warning. */
-  rc = sqlite3VdbeIdxKeyCompare(db, pC, &r, &res);
+
+  /* Inlined version of sqlite3VdbeIdxKeyCompare() */
+  {
+    i64 nCellKey = 0;
+    BtCursor *pCur;
+    Mem m;
+
+    assert( pC->eCurType==CURTYPE_BTREE );
+    pCur = pC->uc.pCursor;
+    assert( sqlite3BtreeCursorIsValid(pCur) );
+    nCellKey = sqlite3BtreePayloadSize(pCur);
+    /* nCellKey will always be between 0 and 0xffffffff because of the way
+    ** that btreeParseCellPtr() and sqlite3GetVarint32() are implemented */
+    if( nCellKey<=0 || nCellKey>0x7fffffff ){
+      rc = SQLITE_CORRUPT_BKPT;
+      goto abort_due_to_error;
+    }
+    sqlite3VdbeMemInit(&m, db, 0);
+    rc = sqlite3VdbeMemFromBtreeZeroOffset(pCur, (u32)nCellKey, &m);
+    if( rc ) goto abort_due_to_error;
+    res = sqlite3VdbeRecordCompareWithSkip(m.n, m.z, &r, 0);
+    sqlite3VdbeMemRelease(&m);
+  }
+  /* End of inlined sqlite3VdbeIdxKeyCompare() */
+
  assert( (OP_IdxLE&1)==(OP_IdxLT&1) && (OP_IdxGE&1)==(OP_IdxGT&1) );
  if( (pOp->opcode&1)==(OP_IdxLT&1) ){
    assert( pOp->opcode==OP_IdxLE || pOp->opcode==OP_IdxLT );
@@ -5907,7 +6104,7 @@ case OP_IdxGE:  {       /* jump */
    res++;
  }
  VdbeBranchTaken(res>0,2);
-  if( rc ) goto abort_due_to_error;
+  assert( rc==SQLITE_OK );
  if( res>0 ) goto jump_to_p2;
  break;
 }
@@ -6785,6 +6982,7 @@ case OP_AggStep: {

  pOp->opcode = OP_AggStep1;
  /* Fall through into OP_AggStep */
+  /* no break */ deliberate_fall_through
 }
 case OP_AggStep1: {
  int i;
@@ -7032,7 +7230,7 @@ case OP_JournalMode: {    /* out2 */
      /* Open a transaction on the database file. Regardless of the journal
      ** mode, this transaction always uses a rollback journal.
      */
-      assert( sqlite3BtreeIsInTrans(pBt)==0 );
+      assert( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE );
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeSetVersion(pBt, (eNew==PAGER_JOURNALMODE_WAL ? 2 : 1));
      }
@@ -7774,18 +7972,17 @@ case OP_Init: {          /* jump */
  ){
 #ifndef SQLITE_OMIT_DEPRECATED
    if( db->mTrace & SQLITE_TRACE_LEGACY ){
-      void (*x)(void*,const char*) = (void(*)(void*,const char*))db->xTrace;
      char *z = sqlite3VdbeExpandSql(p, zTrace);
-      x(db->pTraceArg, z);
+      db->trace.xLegacy(db->pTraceArg, z);
      sqlite3_free(z);
    }else
 #endif
    if( db->nVdbeExec>1 ){
      char *z = sqlite3MPrintf(db, "-- %s", zTrace);
-      (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, z);
+      (void)db->trace.xV2(SQLITE_TRACE_STMT, db->pTraceArg, p, z);
      sqlite3DbFree(db, z);
    }else{
-      (void)db->xTrace(SQLITE_TRACE_STMT, db->pTraceArg, p, zTrace);
+      (void)db->trace.xV2(SQLITE_TRACE_STMT, db->pTraceArg, p, zTrace);
    }
  }
 #ifdef SQLITE_USE_FCNTL_TRACE
@@ -7973,7 +8170,11 @@ default: {          /* This is really OP_Noop, OP_Explain */
  ** an error of some kind.
  */
 abort_due_to_error:
-  if( db->mallocFailed ) rc = SQLITE_NOMEM_BKPT;
+  if( db->mallocFailed ){
+    rc = SQLITE_NOMEM_BKPT;
+  }else if( rc==SQLITE_IOERR_CORRUPTFS ){
+    rc = SQLITE_CORRUPT_BKPT;
+  }
  assert( rc );
  if( p->zErrMsg==0 && rc!=SQLITE_IOERR_NOMEM ){
    sqlite3VdbeError(p, "%s", sqlite3ErrStr(rc));
@@ -86,7 +86,7 @@ struct VdbeCursor {
  Bool isEphemeral:1;     /* True for an ephemeral table */
  Bool useRandomRowid:1;  /* Generate new record numbers semi-randomly */
  Bool isOrdered:1;       /* True if the table is not BTREE_UNORDERED */
-  Bool seekHit:1;         /* See the OP_SeekHit and OP_IfNoHope opcodes */
+  u16 seekHit;            /* See the OP_SeekHit and OP_IfNoHope opcodes */
  Btree *pBtx;            /* Separate file holding temporary table */
  i64 seqCount;           /* Sequence counter */
  u32 *aAltMap;           /* Mapping from table to index column numbers */
@@ -73,7 +73,7 @@ static SQLITE_NOINLINE void invokeProfileCallback(sqlite3 *db, Vdbe *p){
  }
 #endif
  if( db->mTrace & SQLITE_TRACE_PROFILE ){
-    db->xTrace(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
+    db->trace.xV2(SQLITE_TRACE_PROFILE, db->pTraceArg, p, (void*)&iElapse);
  }
  p->startTime = 0;
 }
@@ -475,6 +475,7 @@ void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
  int j;
  sqlite3VdbeAddOp4(p, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
  for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
+  sqlite3MayAbort(p->pParse);
 }

 /*
@@ -703,7 +704,7 @@ int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
    if( opcode==OP_Destroy || opcode==OP_VUpdate || opcode==OP_VRename 
     || opcode==OP_VDestroy
     || opcode==OP_VCreate
-     || (opcode==OP_ParseSchema && pOp->p4.z==0)
+     || opcode==OP_ParseSchema
     || ((opcode==OP_Halt || opcode==OP_HaltIfNull) 
      && ((pOp->p1)!=SQLITE_OK && pOp->p2==OE_Abort))
    ){
@@ -808,7 +809,7 @@ static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
      switch( pOp->opcode ){
        case OP_Transaction: {
          if( pOp->p2!=0 ) p->readOnly = 0;
-          /* fall thru */
+          /* no break */ deliberate_fall_through
        }
        case OP_AutoCommit:
        case OP_Savepoint: {
@@ -855,6 +856,7 @@ static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
          n = pOp[-1].p1;
          if( n>nMaxArgs ) nMaxArgs = n;
          /* Fall through into the default case */
+          /* no break */ deliberate_fall_through
        }
 #endif
        default: {
@@ -1520,7 +1522,7 @@ char *sqlite3VdbeDisplayComment(
              sqlite3_str_appendf(&x, "%d", v1);
            }else if( pCtx->argc>1 ){
              sqlite3_str_appendf(&x, "%d..%d", v1, v1+pCtx->argc-1);
-            }else{
+            }else if( x.accError==0 ){
              assert( x.nChar>2 );
              x.nChar -= 2;
              ii++;
@@ -2662,7 +2664,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
  */ 
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){ 
    Btree *pBt = db->aDb[i].pBt;
-    if( sqlite3BtreeIsInTrans(pBt) ){
+    if( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE ){
      /* Whether or not a database might need a super-journal depends upon
      ** its journal mode (among other things).  This matrix determines which
      ** journal modes use a super-journal and which do not */
@@ -2797,7 +2799,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
    */
    for(i=0; i<db->nDb; i++){
      Btree *pBt = db->aDb[i].pBt;
-      if( sqlite3BtreeIsInTrans(pBt) ){
+      if( sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE ){
        char const *zFile = sqlite3BtreeGetJournalname(pBt);
        if( zFile==0 ){
          continue;  /* Ignore TEMP and :memory: databases */
@@ -4293,9 +4295,12 @@ SQLITE_NOINLINE int sqlite3BlobCompare(const Mem *pB1, const Mem *pB2){
 static int sqlite3IntFloatCompare(i64 i, double r){
  if( sizeof(LONGDOUBLE_TYPE)>8 ){
    LONGDOUBLE_TYPE x = (LONGDOUBLE_TYPE)i;
+    testcase( x<r );
+    testcase( x>r );
+    testcase( x==r );
    if( x<r ) return -1;
-    if( x>r ) return +1;
-    return 0;
+    if( x>r ) return +1;  /*NO_TEST*/ /* work around bugs in gcov */
+    return 0;             /*NO_TEST*/ /* work around bugs in gcov */
  }else{
    i64 y;
    double s;
@@ -970,13 +970,16 @@ int sqlite3VdbeSorterInit(
  if( pSorter==0 ){
    rc = SQLITE_NOMEM_BKPT;
  }else{
+    Btree *pBt = db->aDb[0].pBt;
    pSorter->pKeyInfo = pKeyInfo = (KeyInfo*)((u8*)pSorter + sz);
    memcpy(pKeyInfo, pCsr->pKeyInfo, szKeyInfo);
    pKeyInfo->db = 0;
    if( nField && nWorker==0 ){
      pKeyInfo->nKeyField = nField;
    }
-    pSorter->pgsz = pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
+    sqlite3BtreeEnter(pBt);
+    pSorter->pgsz = pgsz = sqlite3BtreeGetPageSize(pBt);
+    sqlite3BtreeLeave(pBt);
    pSorter->nTask = nWorker + 1;
    pSorter->iPrev = (u8)(nWorker - 1);
    pSorter->bUseThreads = (pSorter->nTask>1);
--- a/Show More
+++ b/Show More
@@ -1 +1 @@
 .33.0
 .34.1