TCL tests now all pass.

FossilOrigin-Name: f864baccd3fe0ee939ac1ec20069792f649cddc0

Makefile.in

@@ -26,7 +26,8 @@ BCC = @BUILD_CC@ @BUILD_CFLAGS@
 # will run on the target platform.  (BCC and TCC are usually the
 # same unless your are cross-compiling.)
 #
-TCC = @CC@ @CPPFLAGS@ @CFLAGS@ -I. -I${TOP}/src -I${TOP}/ext/rtree
+TCC = @CC@ @CPPFLAGS@ @CFLAGS@ -I. -I${TOP}/src -I${TOP}/ext/rtree -I${TOP}/ext/icu
+TCC += -I${TOP}/ext/fts3 -I${TOP}/ext/async -I${TOP}/ext/session
 
 # Define this for the autoconf-based build, so that the code knows it can
 # include the generated config.h
@@ -76,6 +77,7 @@ TEMP_STORE = -DSQLITE_TEMP_STORE=@TEMP_STORE@
 # The same set of OMIT and ENABLE flags should be passed to the 
 # LEMON parser generator and the mkkeywordhash tool as well.
 OPT_FEATURE_FLAGS = @OPT_FEATURE_FLAGS@
+OPT_FEATURE_FLAGS += -DSQLITE_ENABLE_SESSION -DSQLITE_ENABLE_PREUPDATE_HOOK
 
 TCC += $(OPT_FEATURE_FLAGS)
 
@@ -176,7 +178,8 @@ LIBOBJS0 = alter.lo analyze.lo attach.lo auth.lo \
          mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
          notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
          pager.lo parse.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
-         random.lo resolve.lo rowset.lo rtree.lo select.lo status.lo \
+         random.lo resolve.lo rowset.lo rtree.lo \
+         sqlite3session.lo select.lo status.lo \
          table.lo tokenize.lo trigger.lo \
          update.lo util.lo vacuum.lo \
          vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
@@ -328,6 +331,10 @@ SRC += \
 SRC += \
   $(TOP)/ext/rtree/rtree.h \
   $(TOP)/ext/rtree/rtree.c
+SRC += \
+  $(TOP)/ext/session/sqlite3session.c \
+  $(TOP)/ext/session/sqlite3session.h
+
 
 
 # Generated source code files
@@ -384,7 +391,8 @@ TESTSRC = \
   $(TOP)/src/test_vfs.c \
   $(TOP)/src/test_wsd.c       \
   $(TOP)/ext/fts3/fts3_term.c \
-  $(TOP)/ext/fts3/fts3_test.c 
+  $(TOP)/ext/fts3/fts3_test.c  \
+  $(TOP)/ext/session/test_session.c
 
 # Statically linked extensions
 #
@@ -443,7 +451,8 @@ TESTSRC2 = \
   $(TOP)/ext/fts3/fts3_term.c \
   $(TOP)/ext/fts3/fts3_tokenizer.c \
   $(TOP)/ext/fts3/fts3_write.c \
-  $(TOP)/ext/async/sqlite3async.c
+  $(TOP)/ext/async/sqlite3async.c \
+  $(TOP)/ext/session/sqlite3session.c 
 
 # Header files used by all library source files.
 #
@@ -541,6 +550,7 @@ mptester$(EXE):	sqlite3.c $(TOP)/mptest/mptest.c
 sqlite3.c:	.target_source $(TOP)/tool/mksqlite3c.tcl
 	$(TCLSH_CMD) $(TOP)/tool/mksqlite3c.tcl
 	cp tsrc/shell.c tsrc/sqlite3ext.h .
+	cp $(TOP)/ext/session/sqlite3session.h .
 
 tclsqlite3.c:	sqlite3.c
 	echo '#ifndef USE_SYSTEM_SQLITE' >tclsqlite3.c
@@ -889,6 +899,9 @@ fts3_write.lo:	$(TOP)/ext/fts3/fts3_write.c $(HDR) $(EXTHDR)
 rtree.lo:	$(TOP)/ext/rtree/rtree.c $(HDR) $(EXTHDR)
 	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/rtree/rtree.c
 
+sqlite3session.lo:	$(TOP)/ext/session/sqlite3session.c $(HDR) $(EXTHDR)
+	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)/ext/session/sqlite3session.c
+
 
 # Rules to build the 'testfixture' application.
 #

Makefile.msc

@@ -268,6 +268,8 @@ TCC = $(TCC) -I$(TOP)\ext\fts3
 RCC = $(RCC) -I$(TOP)\ext\fts3
 TCC = $(TCC) -I$(TOP)\ext\rtree
 RCC = $(RCC) -I$(TOP)\ext\rtree
+TCC = $(TCC) -I$(TOP)\ext\session
+RCC = $(RCC) -I$(TOP)\ext\session
 !ENDIF
 
 # The mksqlite3c.tcl script accepts some options on the command
@@ -434,6 +436,8 @@ RCC = $(RCC) -DSQLITE_TEMP_STORE=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_FTS3=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_RTREE=1
 OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_COLUMN_METADATA=1
+OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_SESSION=1
+OPT_FEATURE_FLAGS = $(OPT_FEATURE_FLAGS) -DSQLITE_ENABLE_PREUPDATE_HOOK=1
 # END standard options
 
 # BEGIN required Windows option
@@ -563,7 +567,8 @@ LIBOBJS0 = vdbe.lo parse.lo alter.lo analyze.lo attach.lo auth.lo \
          mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
          notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
          pager.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
-         random.lo resolve.lo rowset.lo rtree.lo select.lo status.lo \
+         random.lo resolve.lo rowset.lo rtree.lo \
+         sqlite3session.lo select.lo status.lo \
          table.lo tokenize.lo trigger.lo \
          update.lo util.lo vacuum.lo \
          vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
@@ -726,6 +731,9 @@ SRC = $(SRC) \
 SRC = $(SRC) \
   $(TOP)\ext\rtree\rtree.h \
   $(TOP)\ext\rtree\rtree.c
+SRC = $(SRC) \
+  $(TOP)\ext\session\sqlite3session.h \
+  $(TOP)\ext\session\sqlite3session.c
 
 
 # Generated source code files
@@ -781,7 +789,8 @@ TESTSRC = \
   $(TOP)\src\test_vfs.c \
   $(TOP)\src\test_wsd.c \
   $(TOP)\ext\fts3\fts3_term.c \
-  $(TOP)\ext\fts3\fts3_test.c
+  $(TOP)\ext\fts3\fts3_test.c \
+  $(TOP)\ext\session\test_session.c
 
 # Statically linked extensions
 #
@@ -799,6 +808,7 @@ TESTEXT = \
 
 
 # Source code to the library files needed by the test fixture
+# (non-amalgamation)
 #
 TESTSRC2 = \
   $(TOP)\src\attach.c \
@@ -844,7 +854,14 @@ TESTSRC2 = \
   $(TOP)\ext\fts3\fts3_unicode.c \
   $(TOP)\ext\fts3\fts3_unicode2.c \
   $(TOP)\ext\fts3\fts3_write.c \
-  $(TOP)\ext\async\sqlite3async.c
+  $(TOP)\ext\async\sqlite3async.c \
+  $(TOP)\ext\session\sqlite3session.c
+
+# Source code to the library files needed by the test fixture
+# (amalgamation)
+#
+TESTSRC3 =
+
 
 # Header files used by all library source files.
 #
@@ -890,6 +907,8 @@ EXTHDR = $(EXTHDR) \
   $(TOP)\ext\icu\sqliteicu.h
 EXTHDR = $(EXTHDR) \
   $(TOP)\ext\rtree\sqlite3rtree.h
+EXTHDR = $(EXTHDR) \
+  $(TOP)\ext\session\sqlite3session.h
 
 # This is the default Makefile target.  The objects listed here
 # are what get build when you type just "make" with no arguments.
@@ -930,6 +949,7 @@ sqlite3.c:	.target_source $(TOP)\tool\mksqlite3c.tcl
 	$(TCLSH_CMD) $(TOP)\tool\mksqlite3c.tcl $(MKSQLITE3C_ARGS)
 	copy tsrc\shell.c .
 	copy tsrc\sqlite3ext.h .
+	copy $(TOP)\ext\session\sqlite3session.h .
 
 sqlite3-all.c:	sqlite3.c $(TOP)\tool\split-sqlite3c.tcl
 	$(TCLSH_CMD) $(TOP)\tool\split-sqlite3c.tcl
@@ -1294,6 +1314,9 @@ fts3_write.lo:	$(TOP)\ext\fts3\fts3_write.c $(HDR) $(EXTHDR)
 rtree.lo:	$(TOP)\ext\rtree\rtree.c $(HDR) $(EXTHDR)
 	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)\ext\rtree\rtree.c
 
+sqlite3session.lo:	$(TOP)\ext\session\sqlite3sesion.c $(HDR) $(EXTHDR)
+	$(LTCOMPILE) -DSQLITE_CORE -c $(TOP)\ext\session\sqlite3session.c
+
 
 # Rules to build the 'testfixture' application.
 #
@@ -1306,7 +1329,7 @@ TESTFIXTURE_FLAGS = -DTCLSH=1 -DSQLITE_TEST=1 -DSQLITE_CRASH_TEST=1
 TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERVER=1 -DSQLITE_PRIVATE="" -DSQLITE_CORE
 
 TESTFIXTURE_SRC0 = $(TESTEXT) $(TESTSRC2) libsqlite3.lib
-TESTFIXTURE_SRC1 = $(TESTEXT) $(SQLITE3C)
+TESTFIXTURE_SRC1 = $(TESTEXT) $(TESTSRC3) $(SQLITE3C)
 !IF $(USE_AMALGAMATION)==0
 TESTFIXTURE_SRC = $(TESTSRC) $(TOP)\src\tclsqlite.c $(TESTFIXTURE_SRC0)
 !ELSE

ext/rtree/rtreeB.test

@@ -41,7 +41,7 @@ ifcapable rtree_int_only {
       INSERT INTO t1 VALUES(9223372036854775807, 150, 150, 400, 400);
       SELECT rtreenode(2, data) FROM t1_node;
     }
-  } {{{1073741824 0.000000 0.000000 100.000000 100.000000} {2147483646 0.000000 0.000000 200.000000 200.000000} {4294967296 0.000000 0.000000 300.000000 300.000000} {8589934592 20.000000 20.000000 150.000000 150.000000} {9223372036854775807 150.000000 150.000000 400.000000 400.000000}}}
+  } {{{1073741824 0 0 100 100} {2147483646 0 0 200 200} {4294967296 0 0 300 300} {8589934592 20 20 150 150} {9223372036854775807 150 150 400 400}}}
 }
 
 finish_test

ext/rtree/sqlite3rtree.h

@@ -21,6 +21,16 @@ extern "C" {
 #endif
 
 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
+typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
+
+/* The double-precision datatype used by RTree depends on the
+** SQLITE_RTREE_INT_ONLY compile-time option.
+*/
+#ifdef SQLITE_RTREE_INT_ONLY
+  typedef sqlite3_int64 sqlite3_rtree_dbl;
+#else
+  typedef double sqlite3_rtree_dbl;
+#endif
 
 /*
 ** Register a geometry callback named zGeom that can be used as part of an
@@ -31,11 +41,7 @@ typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
 int sqlite3_rtree_geometry_callback(
   sqlite3 *db,
   const char *zGeom,
-#ifdef SQLITE_RTREE_INT_ONLY
-  int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes),
-#else
-  int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes),
-#endif
+  int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
   void *pContext
 );
 
@@ -47,11 +53,58 @@ int sqlite3_rtree_geometry_callback(
 struct sqlite3_rtree_geometry {
   void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
   int nParam;                     /* Size of array aParam[] */
-  double *aParam;                 /* Parameters passed to SQL geom function */
+  sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
   void *pUser;                    /* Callback implementation user data */
   void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
 };
 
+/*
+** Register a 2nd-generation geometry callback named zScore that can be 
+** used as part of an R-Tree geometry query as follows:
+**
+**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
+*/
+int sqlite3_rtree_query_callback(
+  sqlite3 *db,
+  const char *zQueryFunc,
+  int (*xQueryFunc)(sqlite3_rtree_query_info*),
+  void *pContext,
+  void (*xDestructor)(void*)
+);
+
+
+/*
+** A pointer to a structure of the following type is passed as the 
+** argument to scored geometry callback registered using
+** sqlite3_rtree_query_callback().
+**
+** Note that the first 5 fields of this structure are identical to
+** sqlite3_rtree_geometry.  This structure is a subclass of
+** sqlite3_rtree_geometry.
+*/
+struct sqlite3_rtree_query_info {
+  void *pContext;                   /* pContext from when function registered */
+  int nParam;                       /* Number of function parameters */
+  sqlite3_rtree_dbl *aParam;        /* value of function parameters */
+  void *pUser;                      /* callback can use this, if desired */
+  void (*xDelUser)(void*);          /* function to free pUser */
+  sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
+  int nCoord;                       /* Number of coordinates */
+  int iLevel;                       /* Level of current node or entry */
+  sqlite3_int64 iRowid;             /* Rowid for current entry */
+  sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
+  int eParentWithin;                /* Visibility of parent node */
+  int eWithin;                      /* OUT: Visiblity */
+  sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
+};
+
+/*
+** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
+*/
+#define NOT_WITHIN       0   /* Object completely outside of query region */
+#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
+#define FULLY_WITHIN     2   /* Object fully contained within query region */
+
 
 #ifdef __cplusplus
 }  /* end of the 'extern "C"' block */

ext/session/session1.test

@@ -0,0 +1,509 @@
+# 2011 March 07
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session1
+
+proc do_changeset_test {tn session res} {
+  set r [list]
+  foreach x $res {lappend r $x}
+  uplevel do_test $tn [list [subst -nocommands {
+    set x [list]
+    sqlite3session_foreach c [$session changeset] { lappend x [set c] }
+    set x
+  }]] [list $r]
+}
+
+proc do_changeset_invert_test {tn session res} {
+  set r [list]
+  foreach x $res {lappend r $x}
+  uplevel do_test $tn [list [subst -nocommands {
+    set x [list]
+    set changeset [sqlite3changeset_invert [$session changeset]]
+    sqlite3session_foreach c [set changeset] { lappend x [set c] }
+    set x
+  }]] [list $r]
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(x PRIMARY KEY, y);
+  INSERT INTO t1 VALUES('abc', 'def');
+}
+
+#-------------------------------------------------------------------------
+# Test creating, attaching tables to and deleting session objects.
+#
+do_test 1.1 { sqlite3session S db main } {S}
+do_test 1.2 { S delete } {}
+do_test 1.3 { sqlite3session S db main } {S}
+do_test 1.4 { S attach t1 } {}
+do_test 1.5 { S delete } {}
+do_test 1.6 { sqlite3session S db main } {S}
+do_test 1.7 { S attach t1 ; S attach t2 ; S attach t3 } {}
+do_test 1.8 { S attach t1 ; S attach t2 ; S attach t3 } {}
+do_test 1.9 { S delete } {}
+do_test 1.10 {
+  sqlite3session S db main
+  S attach t1
+  execsql { INSERT INTO t1 VALUES('ghi', 'jkl') }
+} {}
+do_test 1.11 { S delete } {}
+do_test 1.12 {
+  sqlite3session S db main
+  S attach t1
+  execsql { INSERT INTO t1 VALUES('mno', 'pqr') }
+  execsql { UPDATE t1 SET x = 111 WHERE rowid = 1 }
+  execsql { DELETE FROM t1 WHERE rowid = 2 }
+} {}
+do_test 1.13 {
+  S changeset
+  S delete
+} {}
+
+#-------------------------------------------------------------------------
+# Simple changeset tests. Also test the sqlite3changeset_invert() 
+# function.
+#
+do_test 2.1.1 {
+  execsql { DELETE FROM t1 }
+  sqlite3session S db main
+  S attach t1
+  execsql { INSERT INTO t1 VALUES(1, 'Sukhothai') }
+  execsql { INSERT INTO t1 VALUES(2, 'Ayutthaya') }
+  execsql { INSERT INTO t1 VALUES(3, 'Thonburi') }
+} {}
+do_changeset_test 2.1.2 S {
+  {INSERT t1 0 X. {} {i 1 t Sukhothai}}
+  {INSERT t1 0 X. {} {i 2 t Ayutthaya}}
+  {INSERT t1 0 X. {} {i 3 t Thonburi}}
+}
+do_changeset_invert_test 2.1.3 S {
+  {DELETE t1 0 X. {i 1 t Sukhothai} {}}
+  {DELETE t1 0 X. {i 2 t Ayutthaya} {}}
+  {DELETE t1 0 X. {i 3 t Thonburi} {}}
+}
+do_test 2.1.4 { S delete } {}
+
+do_test 2.2.1 {
+  sqlite3session S db main
+  S attach t1
+  execsql { DELETE FROM t1 WHERE 1 }
+} {}
+do_changeset_test 2.2.2 S {
+  {DELETE t1 0 X. {i 1 t Sukhothai} {}}
+  {DELETE t1 0 X. {i 2 t Ayutthaya} {}}
+  {DELETE t1 0 X. {i 3 t Thonburi} {}}
+}
+do_changeset_invert_test 2.2.3 S {
+  {INSERT t1 0 X. {} {i 1 t Sukhothai}}
+  {INSERT t1 0 X. {} {i 2 t Ayutthaya}}
+  {INSERT t1 0 X. {} {i 3 t Thonburi}}
+}
+do_test 2.2.4 { S delete } {}
+
+do_test 2.3.1 {
+  execsql { DELETE FROM t1 }
+  sqlite3session S db main
+  execsql { INSERT INTO t1 VALUES(1, 'Sukhothai') }
+  execsql { INSERT INTO t1 VALUES(2, 'Ayutthaya') }
+  execsql { INSERT INTO t1 VALUES(3, 'Thonburi') }
+  S attach t1
+  execsql { 
+    UPDATE t1 SET x = 10 WHERE x = 1;
+    UPDATE t1 SET y = 'Surin' WHERE x = 2;
+    UPDATE t1 SET x = 20, y = 'Thapae' WHERE x = 3;
+  }
+} {}
+
+do_changeset_test 2.3.2 S {
+  {INSERT t1 0 X. {} {i 10 t Sukhothai}} 
+  {DELETE t1 0 X. {i 1 t Sukhothai} {}} 
+  {UPDATE t1 0 X. {i 2 t Ayutthaya} {{} {} t Surin}} 
+  {DELETE t1 0 X. {i 3 t Thonburi} {}} 
+  {INSERT t1 0 X. {} {i 20 t Thapae}} 
+}
+
+do_changeset_invert_test 2.3.3 S {
+  {DELETE t1 0 X. {i 10 t Sukhothai} {}} 
+  {INSERT t1 0 X. {} {i 1 t Sukhothai}} 
+  {UPDATE t1 0 X. {i 2 t Surin} {{} {} t Ayutthaya}} 
+  {INSERT t1 0 X. {} {i 3 t Thonburi}} 
+  {DELETE t1 0 X. {i 20 t Thapae} {}}
+}
+do_test 2.3.4 { S delete } {}
+
+do_test 2.4.1 {
+  sqlite3session S db main
+  S attach t1
+  execsql { INSERT INTO t1 VALUES(100, 'Bangkok') }
+  execsql { DELETE FROM t1 WHERE x = 100 }
+} {}
+do_changeset_test 2.4.2 S {}
+do_changeset_invert_test 2.4.3 S {}
+do_test 2.4.4 { S delete } {}
+
+#-------------------------------------------------------------------------
+# Test the application of simple changesets. These tests also test that
+# the conflict callback is invoked correctly. For these tests, the 
+# conflict callback always returns OMIT.
+#
+db close
+forcedelete test.db test.db2
+sqlite3 db test.db
+sqlite3 db2 test.db2
+
+proc xConflict {args} { 
+  lappend ::xConflict $args
+  return "" 
+}
+
+proc bgerror {args} { set ::background_error $args }
+
+proc do_conflict_test {tn args} {
+  set O(-tables)    [list]
+  set O(-sql)       [list]
+  set O(-conflicts) [list]
+
+  array set V $args
+  foreach key [array names V] {
+    if {![info exists O($key)]} {error "no such option: $key"}
+  }
+  array set O $args
+
+  sqlite3session S db main
+  foreach t $O(-tables) { S attach $t }
+  execsql $O(-sql)
+  set ::xConflict [list]
+  sqlite3changeset_apply db2 [S changeset] xConflict
+
+  set conflicts [list]
+  foreach c $O(-conflicts) {
+    lappend conflicts $c
+  }
+
+  after 1 {set go 1}
+  vwait go
+
+  uplevel do_test $tn [list { set ::xConflict }] [list $conflicts]
+  S delete
+}
+
+proc do_db2_test {testname sql {result {}}} {
+  uplevel do_test $testname [list "execsql {$sql} db2"] [list [list {*}$result]]
+}
+
+# Test INSERT changesets.
+#
+do_test 3.1.0 {
+  execsql { CREATE TABLE t1(a PRIMARY KEY, b NOT NULL) } db2
+  execsql { 
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    INSERT INTO t1 VALUES(1, 'one');
+    INSERT INTO t1 VALUES(2, 'two');
+  } db 
+} {}
+do_db2_test 3.1.1 "INSERT INTO t1 VALUES(6, 'VI')"
+do_conflict_test 3.1.2 -tables t1 -sql {
+  INSERT INTO t1 VALUES(3, 'three');
+  INSERT INTO t1 VALUES(4, 'four');
+  INSERT INTO t1 VALUES(5, 'five');
+  INSERT INTO t1 VALUES(6, 'six');
+  INSERT INTO t1 VALUES(7, 'seven');
+  INSERT INTO t1 VALUES(8, NULL);
+} -conflicts {
+  {INSERT t1 CONSTRAINT {i 8 n {}}}
+  {INSERT t1 CONFLICT {i 6 t six} {i 6 t VI}}
+}
+
+do_db2_test 3.1.3 "SELECT * FROM t1" {
+  6 VI 3 three 4 four 5 five 7 seven
+}
+do_execsql_test 3.1.4 "SELECT * FROM t1" {
+  1 one 2 two 3 three 4 four 5 five 6 six 7 seven 8 {}
+}
+
+# Test DELETE changesets.
+#
+do_execsql_test 3.2.1 {
+  PRAGMA foreign_keys = on;
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  CREATE TABLE t3(c, d REFERENCES t2);
+  INSERT INTO t2 VALUES(1, 'one');
+  INSERT INTO t2 VALUES(2, 'two');
+  INSERT INTO t2 VALUES(3, 'three');
+  INSERT INTO t2 VALUES(4, 'four');
+}
+do_db2_test 3.2.2 {
+  PRAGMA foreign_keys = on;
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  CREATE TABLE t3(c, d REFERENCES t2);
+  INSERT INTO t2 VALUES(1, 'one');
+  INSERT INTO t2 VALUES(2, 'two');
+  INSERT INTO t2 VALUES(4, 'five');
+  INSERT INTO t3 VALUES('i', 1);
+}
+do_conflict_test 3.2.3 -tables t2 -sql {
+  DELETE FROM t2 WHERE a = 1;
+  DELETE FROM t2 WHERE a = 2;
+  DELETE FROM t2 WHERE a = 3;
+  DELETE FROM t2 WHERE a = 4;
+} -conflicts {
+  {DELETE t2 NOTFOUND {i 3 t three}}
+  {DELETE t2 DATA {i 4 t four} {i 4 t five}}
+  {FOREIGN_KEY 1}
+}
+do_execsql_test 3.2.4 "SELECT * FROM t2" {}
+do_db2_test     3.2.5 "SELECT * FROM t2" {4 five}
+
+# Test UPDATE changesets.
+#
+do_execsql_test 3.3.1 {
+  CREATE TABLE t4(a, b, c, PRIMARY KEY(b, c));
+  INSERT INTO t4 VALUES(1, 2, 3);
+  INSERT INTO t4 VALUES(4, 5, 6);
+  INSERT INTO t4 VALUES(7, 8, 9);
+  INSERT INTO t4 VALUES(10, 11, 12);
+}
+do_db2_test 3.3.2 {
+  CREATE TABLE t4(a NOT NULL, b, c, PRIMARY KEY(b, c));
+  INSERT INTO t4 VALUES(0, 2, 3);
+  INSERT INTO t4 VALUES(4, 5, 7);
+  INSERT INTO t4 VALUES(7, 8, 9);
+  INSERT INTO t4 VALUES(10, 11, 12);
+}
+do_conflict_test 3.3.3 -tables t4 -sql {
+  UPDATE t4 SET a = -1 WHERE b = 2;
+  UPDATE t4 SET a = -1 WHERE b = 5;
+  UPDATE t4 SET a = NULL WHERE c = 9;
+  UPDATE t4 SET a = 'x' WHERE b = 11;
+} -conflicts {
+  {UPDATE t4 CONSTRAINT {i 7 i 8 i 9} {n {} {} {} {} {}}}
+  {UPDATE t4 DATA {i 1 i 2 i 3} {i -1 {} {} {} {}} {i 0 i 2 i 3}}
+  {UPDATE t4 NOTFOUND {i 4 i 5 i 6} {i -1 {} {} {} {}}}
+}
+do_db2_test     3.3.4 { SELECT * FROM t4 } {0 2 3 4 5 7 7 8 9 x 11 12}
+do_execsql_test 3.3.5 { SELECT * FROM t4 } {-1 2 3 -1 5 6 {} 8 9 x 11 12}
+
+#-------------------------------------------------------------------------
+# This next block of tests verifies that values returned by the conflict
+# handler are intepreted correctly.
+#
+
+proc test_reset {} {
+  db close
+  db2 close
+  forcedelete test.db test.db2
+  sqlite3 db test.db
+  sqlite3 db2 test.db2
+}
+
+proc xConflict {args} {
+  lappend ::xConflict $args
+  return $::conflict_return
+}
+
+foreach {tn conflict_return after} {
+  1 OMIT      {1 2 value1   4 5 7       10 x x}
+  2 REPLACE   {1 2 value1   4 5 value2  10 8 9}
+} {
+  test_reset
+
+  do_test 4.$tn.1 {
+    foreach db {db db2} {
+      execsql { 
+        CREATE TABLE t1(a, b, c, PRIMARY KEY(a));
+        INSERT INTO t1 VALUES(1, 2, 3);
+        INSERT INTO t1 VALUES(4, 5, 6);
+        INSERT INTO t1 VALUES(7, 8, 9);
+      } $db
+    }
+    execsql { 
+      REPLACE INTO t1 VALUES(4, 5, 7);
+      REPLACE INTO t1 VALUES(10, 'x', 'x');
+    } db2
+  } {}
+
+  do_conflict_test 4.$tn.2 -tables t1 -sql {
+    UPDATE t1 SET c = 'value1' WHERE a = 1;       -- no conflict
+    UPDATE t1 SET c = 'value2' WHERE a = 4;       -- DATA conflict
+    UPDATE t1 SET a = 10 WHERE a = 7;             -- CONFLICT conflict
+  } -conflicts {
+    {INSERT t1 CONFLICT {i 10 i 8 i 9} {i 10 t x t x}}
+    {UPDATE t1 DATA {i 4 {} {} i 6} {{} {} {} {} t value2} {i 4 i 5 i 7}}
+  }
+
+  do_db2_test 4.$tn.3 "SELECT * FROM t1 ORDER BY a" $after
+}
+
+foreach {tn conflict_return} {
+  1 OMIT
+  2 REPLACE
+} {
+  test_reset
+
+  do_test 5.$tn.1 {
+    # Create an identical schema in both databases.
+    set schema {
+      CREATE TABLE "'foolish name'"(x, y, z, PRIMARY KEY(x, y));
+    }
+    execsql $schema db
+    execsql $schema db2
+
+    # Add some rows to [db2]. These rows will cause conflicts later
+    # on when the changeset from [db] is applied to it.
+    execsql { 
+      INSERT INTO "'foolish name'" VALUES('one', 'one', 'ii');
+      INSERT INTO "'foolish name'" VALUES('one', 'two', 'i');
+      INSERT INTO "'foolish name'" VALUES('two', 'two', 'ii');
+    } db2
+
+  } {}
+
+  do_conflict_test 5.$tn.2 -tables {{'foolish name'}} -sql {
+    INSERT INTO "'foolish name'" VALUES('one', 'two', 2);
+  } -conflicts {
+    {INSERT {'foolish name'} CONFLICT {t one t two i 2} {t one t two t i}}
+  }
+
+  set res(REPLACE) {one one ii one two 2 two two ii}
+  set res(OMIT)    {one one ii one two i two two ii}
+  do_db2_test 5.$tn.3 {
+    SELECT * FROM "'foolish name'" ORDER BY x, y
+  } $res($conflict_return)
+
+
+  do_test 5.$tn.1 {
+    set schema {
+      CREATE TABLE d1("z""z" PRIMARY KEY, y);
+      INSERT INTO d1 VALUES(1, 'one');
+      INSERT INTO d1 VALUES(2, 'two');
+    }
+    execsql $schema db
+    execsql $schema db2
+
+    execsql { 
+      UPDATE d1 SET y = 'TWO' WHERE "z""z" = 2;
+    } db2
+
+  } {}
+
+  do_conflict_test 5.$tn.2 -tables d1 -sql {
+    DELETE FROM d1 WHERE "z""z" = 2;
+  } -conflicts {
+    {DELETE d1 DATA {i 2 t two} {i 2 t TWO}}
+  }
+
+  set res(REPLACE) {1 one}
+  set res(OMIT)    {1 one 2 TWO}
+  do_db2_test 5.$tn.3 "SELECT * FROM d1" $res($conflict_return)
+}
+
+#-------------------------------------------------------------------------
+# Test that two tables can be monitored by a single session object.
+#
+test_reset
+set schema {
+  CREATE TABLE t1(a COLLATE nocase PRIMARY KEY, b);
+  CREATE TABLE t2(a, b PRIMARY KEY);
+}
+do_test 6.0 {
+  execsql $schema db
+  execsql $schema db2
+  execsql {
+    INSERT INTO t1 VALUES('a', 'b');
+    INSERT INTO t2 VALUES('a', 'b');
+  } db2
+} {}
+
+set conflict_return ""
+do_conflict_test 6.1 -tables {t1 t2} -sql {
+  INSERT INTO t1 VALUES('1', '2');
+  INSERT INTO t1 VALUES('A', 'B');
+  INSERT INTO t2 VALUES('A', 'B');
+} -conflicts {
+  {INSERT t1 CONFLICT {t A t B} {t a t b}}
+}
+
+do_db2_test 6.2 "SELECT * FROM t1" {a b 1 2}
+do_db2_test 6.3 "SELECT * FROM t2" {a b A B}
+
+#-------------------------------------------------------------------------
+# Test that session objects are not confused by changes to table in
+# other databases.
+#
+catch { db2 close }
+drop_all_tables
+forcedelete test.db2
+do_iterator_test 7.1 * {
+  ATTACH 'test.db2' AS aux;
+  CREATE TABLE main.t1(x PRIMARY KEY, y);
+  CREATE TABLE aux.t1(x PRIMARY KEY, y);
+
+  INSERT INTO main.t1 VALUES('one', 1);
+  INSERT INTO main.t1 VALUES('two', 2);
+  INSERT INTO aux.t1 VALUES('three', 3);
+  INSERT INTO aux.t1 VALUES('four', 4);
+} {
+  {INSERT t1 0 X. {} {t two i 2}} 
+  {INSERT t1 0 X. {} {t one i 1}}
+}
+
+#-------------------------------------------------------------------------
+# Test the sqlite3session_isempty() function.
+#
+do_test 8.1 {
+  execsql {
+    CREATE TABLE t5(x PRIMARY KEY, y);
+    CREATE TABLE t6(x PRIMARY KEY, y);
+    INSERT INTO t5 VALUES('a', 'b');
+    INSERT INTO t6 VALUES('a', 'b');
+  }
+  sqlite3session S db main
+  S attach *
+
+  S isempty
+} {1}
+do_test 8.2 {
+  execsql { DELETE FROM t5 }
+  S isempty
+} {0}
+do_test 8.3 {
+  S delete
+  sqlite3session S db main
+  S attach t5
+  execsql { DELETE FROM t5 }
+  S isempty
+} {1}
+do_test 8.4 { S delete } {}
+
+#-------------------------------------------------------------------------
+#
+do_execsql_test 9.1 {
+  CREATE TABLE t7(a, b, c, d, e PRIMARY KEY, f, g);
+  INSERT INTO t7 VALUES(1, 1, 1, 1, 1, 1, 1);
+}
+do_test 9.2 { 
+  sqlite3session S db main 
+  S attach *
+  execsql { UPDATE t7 SET b=2, d=2 }
+} {}
+do_changeset_test 9.2 S {{UPDATE t7 0 ....X.. {{} {} i 1 {} {} i 1 i 1 {} {} {} {}} {{} {} i 2 {} {} i 2 {} {} {} {} {} {}}}}
+S delete
+catch { db2 close }
+finish_test

ext/session/session2.test

@@ -0,0 +1,581 @@
+# 2011 Mar 16
+#
+# 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.
+#
+#***********************************************************************
+#
+# The focus of this file is testing the session module.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session2
+
+proc test_reset {} {
+  catch { db close }
+  catch { db2 close }
+  forcedelete test.db test.db2
+  sqlite3 db test.db
+  sqlite3 db2 test.db2
+}
+
+##########################################################################
+# End of proc definitions. Start of tests.
+##########################################################################
+
+test_reset
+do_execsql_test 1.0 { 
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES('i', 'one');
+}
+do_iterator_test 1.1 t1 {
+  DELETE FROM t1 WHERE a = 'i';
+  INSERT INTO t1 VALUES('ii', 'two');
+} {
+  {DELETE t1 0 X. {t i t one} {}} 
+  {INSERT t1 0 X. {} {t ii t two}}
+}
+
+do_iterator_test 1.2 t1 {
+  INSERT INTO t1 VALUES(1.5, 99.9)
+} {
+  {INSERT t1 0 X. {} {f 1.5 f 99.9}}
+}
+
+do_iterator_test 1.3 t1 {
+  UPDATE t1 SET b = 100.1 WHERE a = 1.5;
+  UPDATE t1 SET b = 99.9 WHERE a = 1.5;
+} { }
+
+do_iterator_test 1.4 t1 {
+  UPDATE t1 SET b = 100.1 WHERE a = 1.5;
+} {
+  {UPDATE t1 0 X. {f 1.5 f 99.9} {{} {} f 100.1}}
+}
+
+
+# Execute each of the following blocks of SQL on database [db1]. Collect
+# changes using a session object. Apply the resulting changeset to
+# database [db2]. Then check that the contents of the two databases are
+# identical.
+#
+
+set set_of_tests {
+  1 { INSERT INTO %T1% VALUES(1, 2) } 
+
+  2 {
+    INSERT INTO %T2% VALUES(1, NULL);
+    INSERT INTO %T2% VALUES(2, NULL);
+    INSERT INTO %T2% VALUES(3, NULL);
+    DELETE FROM %T2% WHERE a = 2;
+    INSERT INTO %T2% VALUES(4, NULL);
+    UPDATE %T2% SET b=0 WHERE b=1;
+  } 
+
+  3 { INSERT INTO %T3% SELECT *, NULL FROM %T2% }
+
+  4 {
+    INSERT INTO %T3% SELECT a||a, b||b, NULL FROM %T3%;
+    DELETE FROM %T3% WHERE rowid%2;
+  }
+
+  5 { UPDATE %T3% SET c = a||b }
+
+  6 { UPDATE %T1% SET a = 32 }
+
+  7 { 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%; 
+    DELETE FROM %T1% WHERE (rowid%3)==0;
+  }
+
+  8 {
+    BEGIN;
+      INSERT INTO %T1% SELECT randomblob(32), randomblob(32) FROM %T1%;
+    ROLLBACK;
+  }
+  9 {
+    BEGIN;
+      UPDATE %T1% SET b = 'xxx';
+    ROLLBACK;
+  }
+  10 {
+    BEGIN;
+      DELETE FROM %T1% WHERE 1;
+    ROLLBACK;
+  }
+  11 {
+    INSERT INTO %T1% VALUES(randomblob(21000), randomblob(0));
+    INSERT INTO %T1% VALUES(1.5, 1.5);
+    INSERT INTO %T1% VALUES(4.56, -99.999999999999999999999);
+  }
+  12 {
+    INSERT INTO %T2% VALUES(NULL, NULL);
+  }
+
+  13 {
+    DELETE FROM %T1% WHERE 1;
+
+    -- Insert many rows with real primary keys. Enough to force the session
+    -- objects hash table to resize. 
+    INSERT INTO %T1% VALUES(0.1, 0.1);
+    INSERT INTO %T1% SELECT a+0.1, b+0.1 FROM %T1%;
+    INSERT INTO %T1% SELECT a+0.2, b+0.2 FROM %T1%;
+    INSERT INTO %T1% SELECT a+0.4, b+0.4 FROM %T1%;
+    INSERT INTO %T1% SELECT a+0.8, b+0.8 FROM %T1%;
+    INSERT INTO %T1% SELECT a+1.6, b+1.6 FROM %T1%;
+    INSERT INTO %T1% SELECT a+3.2, b+3.2 FROM %T1%;
+    INSERT INTO %T1% SELECT a+6.4, b+6.4 FROM %T1%;
+    INSERT INTO %T1% SELECT a+12.8, b+12.8 FROM %T1%;
+    INSERT INTO %T1% SELECT a+25.6, b+25.6 FROM %T1%;
+    INSERT INTO %T1% SELECT a+51.2, b+51.2 FROM %T1%;
+    INSERT INTO %T1% SELECT a+102.4, b+102.4 FROM %T1%;
+    INSERT INTO %T1% SELECT a+204.8, b+204.8 FROM %T1%;
+  }
+
+  14 {
+    DELETE FROM %T1% WHERE 1;
+  }
+
+  15 {
+    INSERT INTO %T1% VALUES(1, 1);
+    INSERT INTO %T1% SELECT a+2, b+2 FROM %T1%;
+    INSERT INTO %T1% SELECT a+4, b+4 FROM %T1%;
+    INSERT INTO %T1% SELECT a+8, b+8 FROM %T1%;
+    INSERT INTO %T1% SELECT a+256, b+256 FROM %T1%;
+  }
+
+  16 {
+    INSERT INTO %T4% VALUES('abc', 'def');
+    INSERT INTO %T4% VALUES('def', 'abc');
+  }
+  17 { UPDATE %T4% SET b = 1 }
+  18 { DELETE FROM %T4% WHERE 1 }
+}
+
+test_reset
+do_common_sql {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
+  CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
+  CREATE TABLE t4(a, b, PRIMARY KEY(b, a));
+}
+
+foreach {tn sql} [string map {%T1% t1 %T2% t2 %T3% t3 %T4% t4} $set_of_tests] {
+  do_then_apply_sql $sql
+  do_test 2.$tn { compare_db db db2 } {}
+}
+
+# The following block of tests is similar to the last, except that the
+# session object is recording changes made to an attached database. The
+# main database contains a table of the same name as the table being
+# modified within the attached db.
+#
+test_reset
+forcedelete test.db3
+sqlite3 db3 test.db3
+do_test 3.0 {
+  execsql {
+    ATTACH 'test.db3' AS 'aux';
+    CREATE TABLE t1(a, b PRIMARY KEY);
+    CREATE TABLE t2(x, y, z);
+    CREATE TABLE t3(a);
+
+    CREATE TABLE aux.t1(a PRIMARY KEY, b);
+    CREATE TABLE aux.t2(a, b INTEGER PRIMARY KEY);
+    CREATE TABLE aux.t3(a, b, c, PRIMARY KEY(a, b));
+    CREATE TABLE aux.t4(a, b, PRIMARY KEY(b, a));
+  }
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
+    CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
+    CREATE TABLE t4(a, b, PRIMARY KEY(b, a));
+  } db2
+} {}
+
+proc xTrace {args} { puts $args }
+
+foreach {tn sql} [
+  string map {%T1% aux.t1 %T2% aux.t2 %T3% aux.t3 %T4% aux.t4} $set_of_tests
+] {
+  do_then_apply_sql $sql aux
+  do_test 3.$tn { compare_db db2 db3 } {}
+}
+catch {db3 close}
+
+
+#-------------------------------------------------------------------------
+# The following tests verify that NULL values in primary key columns are
+# handled correctly by the session module.
+#
+test_reset
+do_execsql_test 4.0 {
+  CREATE TABLE t1(a PRIMARY KEY);
+  CREATE TABLE t2(a, b, c, PRIMARY KEY(c, b));
+  CREATE TABLE t3(a, b INTEGER PRIMARY KEY);
+}
+
+foreach {tn sql changeset} {
+  1 {
+    INSERT INTO t1 VALUES(123);
+    INSERT INTO t1 VALUES(NULL);
+    INSERT INTO t1 VALUES(456);
+  } {
+    {INSERT t1 0 X {} {i 456}} 
+    {INSERT t1 0 X {} {i 123}}
+  }
+
+  2 {
+    UPDATE t1 SET a = NULL;
+  } {
+    {DELETE t1 0 X {i 456} {}}
+    {DELETE t1 0 X {i 123} {}}
+  }
+
+  3 { DELETE FROM t1 } { }
+
+  4 { 
+    INSERT INTO t3 VALUES(NULL, NULL)
+  } {
+    {INSERT t3 0 .X {} {n {} i 1}} 
+  }
+
+  5 { INSERT INTO t2 VALUES(1, 2, NULL) }    { }
+  6 { INSERT INTO t2 VALUES(1, NULL, 3) }    { }
+  7 { INSERT INTO t2 VALUES(1, NULL, NULL) } { }
+  8 { INSERT INTO t2 VALUES(1, 2, 3) }    { {INSERT t2 0 .XX {} {i 1 i 2 i 3}} }
+  9 { DELETE FROM t2 WHERE 1 }            { {DELETE t2 0 .XX {i 1 i 2 i 3} {}} }
+
+} {
+  do_iterator_test 4.$tn {t1 t2 t3} $sql $changeset
+}
+
+
+#-------------------------------------------------------------------------
+# Test that if NULL is passed to sqlite3session_attach(), all database
+# tables are attached to the session object.
+#
+test_reset
+do_execsql_test 5.0 {
+  CREATE TABLE t1(a PRIMARY KEY);
+  CREATE TABLE t2(x, y PRIMARY KEY);
+}
+
+foreach {tn sql changeset} {
+  1 { INSERT INTO t1 VALUES(35) }     { {INSERT t1 0 X {} {i 35}} }
+  2 { INSERT INTO t2 VALUES(36, 37) } { {INSERT t2 0 .X {} {i 36 i 37}} }
+  3 { 
+    DELETE FROM t1 WHERE 1;
+    UPDATE t2 SET x = 34;
+  } { 
+    {UPDATE t2 0 .X {i 36 i 37} {i 34 {} {}}}
+    {DELETE t1 0 X {i 35} {}}
+  }
+} {
+  do_iterator_test 5.$tn * $sql $changeset
+}
+
+#-------------------------------------------------------------------------
+# The next block of tests verify that the "indirect" flag is set 
+# correctly within changesets. The indirect flag is set for a change
+# if either of the following are true:
+#
+#   * The sqlite3session_indirect() API has been used to set the session
+#     indirect flag to true, or
+#   * The change was made by a trigger.
+#
+# If the same row is updated more than once during a session, then the 
+# change is considered indirect only if all changes meet the criteria 
+# above.
+#
+test_reset
+db function indirect [list S indirect]
+
+do_execsql_test 6.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c);
+
+  CREATE TABLE t2(x PRIMARY KEY, y);
+  CREATE TRIGGER AFTER INSERT ON t2 WHEN new.x%2 BEGIN
+    INSERT INTO t2 VALUES(new.x+1, NULL);
+  END;
+}
+
+do_iterator_test 6.1.1 * {
+  INSERT INTO t1 VALUES(1, 'one', 'i');
+  SELECT indirect(1);
+  INSERT INTO t1 VALUES(2, 'two', 'ii');
+  SELECT indirect(0);
+  INSERT INTO t1 VALUES(3, 'three', 'iii');
+} {
+  {INSERT t1 0 X.. {} {i 1 t one t i}}
+  {INSERT t1 1 X.. {} {i 2 t two t ii}}
+  {INSERT t1 0 X.. {} {i 3 t three t iii}}
+}
+
+do_iterator_test 6.1.2 * {
+  SELECT indirect(1);
+  UPDATE t1 SET c = 'I' WHERE a = 1;
+  SELECT indirect(0);
+} {
+  {UPDATE t1 1 X.. {i 1 {} {} t i} {{} {} {} {} t I}}
+}
+do_iterator_test 6.1.3 * {
+  SELECT indirect(1);
+  UPDATE t1 SET c = '.' WHERE a = 1;
+  SELECT indirect(0);
+  UPDATE t1 SET c = 'o' WHERE a = 1;
+} {
+  {UPDATE t1 0 X.. {i 1 {} {} t I} {{} {} {} {} t o}}
+}
+do_iterator_test 6.1.4 * {
+  SELECT indirect(0);
+  UPDATE t1 SET c = 'x' WHERE a = 1;
+  SELECT indirect(1);
+  UPDATE t1 SET c = 'i' WHERE a = 1;
+} {
+  {UPDATE t1 0 X.. {i 1 {} {} t o} {{} {} {} {} t i}}
+}
+do_iterator_test 6.1.4 * {
+  SELECT indirect(1);
+  UPDATE t1 SET c = 'y' WHERE a = 1;
+  SELECT indirect(1);
+  UPDATE t1 SET c = 'I' WHERE a = 1;
+} {
+  {UPDATE t1 1 X.. {i 1 {} {} t i} {{} {} {} {} t I}}
+}
+
+do_iterator_test 6.1.5 * {
+  INSERT INTO t2 VALUES(1, 'x');
+} {
+  {INSERT t2 0 X. {} {i 1 t x}}
+  {INSERT t2 1 X. {} {i 2 n {}}}
+}
+
+do_iterator_test 6.1.6 * {
+  SELECT indirect(1);
+  INSERT INTO t2 VALUES(3, 'x');
+  SELECT indirect(0);
+  UPDATE t2 SET y = 'y' WHERE x>2;
+} {
+  {INSERT t2 0 X. {} {i 3 t y}}
+  {INSERT t2 0 X. {} {i 4 t y}}
+}
+
+do_iterator_test 6.1.7 * {
+  SELECT indirect(1);
+  DELETE FROM t2 WHERE x = 4;
+  SELECT indirect(0);
+  INSERT INTO t2 VALUES(4, 'new');
+} {
+  {UPDATE t2 0 X. {i 4 t y} {{} {} t new}}
+}
+
+do_iterator_test 6.1.8 * {
+  CREATE TABLE t3(a, b PRIMARY KEY);
+  CREATE TABLE t4(a, b PRIMARY KEY);
+  CREATE TRIGGER t4t AFTER UPDATE ON t4 BEGIN
+    UPDATE t3 SET a = new.a WHERE b = new.b;
+  END;
+
+  SELECT indirect(1);
+  INSERT INTO t3 VALUES('one', 1);
+  INSERT INTO t4 VALUES('one', 1);
+  SELECT indirect(0);
+  UPDATE t4 SET a = 'two' WHERE b = 1;
+} {
+  {INSERT t4 0 .X {} {t two i 1}} 
+  {INSERT t3 1 .X {} {t two i 1}}
+}
+
+sqlite3session S db main
+do_execsql_test 6.2.1 {
+  SELECT indirect(0);
+  SELECT indirect(-1);
+  SELECT indirect(45);
+  SELECT indirect(-100);
+} {0 0 1 1}
+S delete
+
+#-------------------------------------------------------------------------
+# Test that if a conflict-handler that has been passed either NOTFOUND or
+# CONSTRAINT returns REPLACE - the sqlite3changeset_apply() call returns
+# MISUSE and rolls back any changes made so far.
+#
+#   7.1.*: NOTFOUND conflict-callback.
+#   7.2.*: CONSTRAINT conflict-callback.
+#
+proc xConflict {args} {return REPLACE}
+test_reset
+
+do_execsql_test 7.1.1 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES(1, 'one');
+  INSERT INTO t1 VALUES(2, 'two');
+}
+do_test 7.1.2 {
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b NOT NULL);
+    INSERT INTO t1 VALUES(1, 'one');
+  } db2
+} {}
+do_test 7.1.3 {
+  set changeset [changeset_from_sql {
+    UPDATE t1 SET b = 'five' WHERE a = 1;
+    UPDATE t1 SET b = 'six' WHERE a = 2;
+  }]
+  set x [list]
+  sqlite3session_foreach c $changeset { lappend x $c }
+  set x
+} [list \
+  {UPDATE t1 0 X. {i 1 t one} {{} {} t five}} \
+  {UPDATE t1 0 X. {i 2 t two} {{} {} t six}}  \
+]
+do_test 7.1.4 {
+  list [catch {sqlite3changeset_apply db2 $changeset xConflict} msg] $msg
+} {1 SQLITE_MISUSE}
+do_test 7.1.5 { execsql { SELECT * FROM t1 } db2 } {1 one}
+
+do_test 7.2.1 {
+  set changeset [changeset_from_sql { UPDATE t1 SET b = NULL WHERE a = 1 }]
+
+  set x [list]
+  sqlite3session_foreach c $changeset { lappend x $c }
+  set x
+} [list \
+  {UPDATE t1 0 X. {i 1 t five} {{} {} n {}}} \
+]
+do_test 7.2.2 {
+  list [catch {sqlite3changeset_apply db2 $changeset xConflict} msg] $msg
+} {1 SQLITE_MISUSE}
+do_test 7.2.3 { execsql { SELECT * FROM t1 } db2 } {1 one}
+
+#-------------------------------------------------------------------------
+# Test that if a conflict-handler returns ABORT, application of the 
+# changeset is rolled back and the sqlite3changeset_apply() method returns
+# SQLITE_ABORT.
+#
+# Also test that the same thing happens if a conflict handler returns an
+# unrecognized integer value. Except, in this case SQLITE_MISUSE is returned
+# instead of SQLITE_ABORT.
+#
+foreach {tn conflict_return apply_return} {
+  1    ABORT   SQLITE_ABORT
+  2    567     SQLITE_MISUSE
+} {
+  test_reset
+  proc xConflict {args} [list return $conflict_return]
+
+  do_test 8.$tn.0 {
+    do_common_sql { 
+      CREATE TABLE t1(x, y, PRIMARY KEY(x, y));
+      INSERT INTO t1 VALUES('x', 'y');
+    }
+    execsql { INSERT INTO t1 VALUES('w', 'w') }
+
+    set changeset [changeset_from_sql { DELETE FROM t1 WHERE 1 }]
+
+    set x [list]
+    sqlite3session_foreach c $changeset { lappend x $c }
+    set x
+  } [list \
+    {DELETE t1 0 XX {t w t w} {}} \
+    {DELETE t1 0 XX {t x t y} {}} \
+  ]
+
+  do_test 8.$tn.1 {
+    list [catch {sqlite3changeset_apply db2 $changeset xConflict} msg] $msg
+  } [list 1 $apply_return]
+
+  do_test 8.$tn.2 {
+    execsql {SELECT * FROM t1} db2
+  } {x y}
+}
+
+
+#-------------------------------------------------------------------------
+# Try to cause an infinite loop as follows:
+#
+#   1. Have a changeset insert a row that causes a CONFLICT callback,
+#   2. Have the conflict handler return REPLACE,
+#   3. After the session module deletes the conflicting row, have a trigger
+#      re-insert it.
+#   4. Goto step 1...
+#
+# This doesn't work, as the second invocation of the conflict handler is a
+# CONSTRAINT, not a CONFLICT. There is at most one CONFLICT callback for
+# each change in the changeset.
+#
+test_reset
+proc xConflict {type args} { 
+  if {$type == "CONFLICT"} { return REPLACE }
+  return OMIT
+}
+do_test 9.1 {
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+  }
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    INSERT INTO t1 VALUES('x', 2);
+    CREATE TRIGGER tr1 AFTER DELETE ON t1 BEGIN
+      INSERT INTO t1 VALUES(old.a, old.b);
+    END;
+  } db2
+} {}
+do_test 9.2 {
+  set changeset [changeset_from_sql { INSERT INTO t1 VALUES('x', 1) }]
+  sqlite3changeset_apply db2 $changeset xConflict
+} {}
+do_test 9.3 {
+  execsql { SELECT * FROM t1 } db2
+} {x 2}
+
+#-------------------------------------------------------------------------
+#
+test_reset
+db function enable [list S enable]
+
+do_common_sql {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES('x', 'X');
+}
+
+do_iterator_test 10.1 t1 {
+  INSERT INTO t1 VALUES('y', 'Y');
+  SELECT enable(0);
+  INSERT INTO t1 VALUES('z', 'Z');
+  SELECT enable(1);
+} {
+  {INSERT t1 0 X. {} {t y t Y}}
+}
+
+sqlite3session S db main
+do_execsql_test 10.2 {
+  SELECT enable(0);
+  SELECT enable(-1);
+  SELECT enable(1);
+  SELECT enable(-1);
+} {0 0 1 1}
+S delete
+
+finish_test

ext/session/session3.test

@@ -0,0 +1,211 @@
+# 2011 March 24
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for the session module. More
+# specifically, it focuses on testing the session modules response to
+# database schema modifications and mismatches.
+# 
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session3
+
+#-------------------------------------------------------------------------
+# These tests - session3-1.* - verify that the session module behaves
+# correctly when confronted with a schema mismatch when applying a 
+# changeset (in function sqlite3changeset_apply()).
+#
+#   session3-1.1.*: Table does not exist in target db.
+#   session3-1.2.*: Table has wrong number of columns in target db.
+#   session3-1.3.*: Table has wrong PK columns in target db.
+#
+db close
+sqlite3_shutdown
+test_sqlite3_log log
+sqlite3 db test.db
+
+proc log {code msg} { lappend ::log $code $msg }
+
+forcedelete test.db2
+sqlite3 db2 test.db2
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+}
+do_test 1.1 {
+  set ::log {}
+  do_then_apply_sql {
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(3, 4);
+  }
+  set ::log
+} {SQLITE_SCHEMA {sqlite3changeset_apply(): no such table: t1}}
+
+do_test 1.2.0 {
+  execsql { CREATE TABLE t1(a PRIMARY KEY, b, c) } db2
+} {}
+do_test 1.2.1 {
+  set ::log {}
+  do_then_apply_sql {
+    INSERT INTO t1 VALUES(5, 6);
+    INSERT INTO t1 VALUES(7, 8);
+  }
+  set ::log
+} {SQLITE_SCHEMA {sqlite3changeset_apply(): table t1 has 3 columns, expected 2}}
+
+do_test 1.3.0 {
+  execsql { 
+    DROP TABLE t1;
+    CREATE TABLE t1(a, b PRIMARY KEY);
+  } db2
+} {}
+do_test 1.3.1 {
+  set ::log {}
+  do_then_apply_sql {
+    INSERT INTO t1 VALUES(9, 10);
+    INSERT INTO t1 VALUES(11, 12);
+  }
+  set ::log
+} {SQLITE_SCHEMA {sqlite3changeset_apply(): primary key mismatch for table t1}}
+
+#-------------------------------------------------------------------------
+# These tests - session3-2.* - verify that the session module behaves
+# correctly when the schema of an attached table is modified during the
+# session.
+#
+#   session3-2.1.*: Table is dropped midway through the session.
+#   session3-2.2.*: Table is dropped and recreated with a different # cols.
+#   session3-2.3.*: Table is dropped and recreated with a different PK.
+#
+# In all of these scenarios, the call to sqlite3session_changeset() will
+# return SQLITE_SCHEMA. Also:
+#   
+#   session3-2.4.*: Table is dropped and recreated with an identical schema.
+#                   In this case sqlite3session_changeset() returns SQLITE_OK.
+#
+
+do_test 2.1 {
+  execsql { CREATE TABLE t2(a, b PRIMARY KEY) }
+  sqlite3session S db main
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2);
+    DROP TABLE t2;
+  }
+  list [catch { S changeset } msg] $msg
+} {1 SQLITE_SCHEMA}
+
+do_test 2.2.1 {
+  S delete
+  sqlite3session S db main
+  execsql { CREATE TABLE t2(a, b PRIMARY KEY, c) }
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2, 3);
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY);
+  }
+  list [catch { S changeset } msg] $msg
+} {1 SQLITE_SCHEMA}
+do_test 2.2.2 {
+  S delete
+  sqlite3session S db main
+  execsql { 
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY, c);
+  }
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2, 3);
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY, c, d);
+  }
+  list [catch { S changeset } msg] $msg
+} {1 SQLITE_SCHEMA}
+do_test 2.2.3 {
+  S delete
+  sqlite3session S db main
+  execsql { 
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY, c);
+  }
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2, 3);
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY);
+    INSERT INTO t2 VALUES(4, 5);
+  }
+  list [catch { S changeset } msg] $msg
+} {1 SQLITE_SCHEMA}
+do_test 2.2.4 {
+  S delete
+  sqlite3session S db main
+  execsql { 
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY, c);
+  }
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2, 3);
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY, c, d);
+    INSERT INTO t2 VALUES(4, 5, 6, 7);
+  }
+  list [catch { S changeset } msg] $msg
+} {1 SQLITE_SCHEMA}
+
+do_test 2.3 {
+  S delete
+  sqlite3session S db main
+  execsql { 
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY);
+  }
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2);
+    DROP TABLE t2;
+    CREATE TABLE t2(a PRIMARY KEY, b);
+  }
+  list [catch { S changeset } msg] $msg
+} {1 SQLITE_SCHEMA}
+
+do_test 2.4 {
+  S delete
+  sqlite3session S db main
+  execsql { 
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY);
+  }
+  S attach t2
+  execsql {
+    INSERT INTO t2 VALUES(1, 2);
+    DROP TABLE t2;
+    CREATE TABLE t2(a, b PRIMARY KEY);
+  }
+  list [catch { S changeset } msg] $msg
+} {0 {}}
+
+S delete
+
+
+catch { db close }
+catch { db2 close }
+sqlite3_shutdown
+test_sqlite3_log
+sqlite3_initialize
+
+finish_test

ext/session/session4.test

@@ -0,0 +1,68 @@
+# 2011 March 25
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for the session module. 
+# 
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session4
+
+do_test 1.0 {
+  execsql {
+    CREATE TABLE x(a, b, c, d, e, PRIMARY KEY(c, e));
+    INSERT INTO x VALUES(65.21, X'28B0', 16.35, NULL, 'doers');
+    INSERT INTO x VALUES(NULL, 78.49, 2, X'60', -66);
+    INSERT INTO x VALUES('cathedral', NULL, 35, NULL, X'B220937E80A2D8');
+    INSERT INTO x VALUES(NULL, 'masking', -91.37, NULL, X'596D');
+    INSERT INTO x VALUES(19, 'domains', 'espouse', -94, 'throw');
+  }
+
+  sqlite3session S db main
+  set changeset [changeset_from_sql {
+    DELETE FROM x WHERE e = -66;
+    UPDATE x SET a = 'parameterizable', b = 31.8 WHERE c = 35;
+    INSERT INTO x VALUES(-75.61, -17, 16.85, NULL, X'D73DB02678');
+  }]
+  set {} {}
+} {}
+
+
+# This currently causes crashes. sqlite3changeset_invert() does not handle
+# corrupt changesets well.
+if 0 {
+  do_test 1.1 {
+    for {set i 0} {$i < [string length $changeset]} {incr i} {
+      set before [string range $changeset 0 [expr $i-1]]
+      set after  [string range $changeset [expr $i+1] end]
+      for {set j 10} {$j < 260} {incr j} {
+        set x [binary format "a*ca*" $before $j $after]
+        catch { sqlite3changeset_invert $x }
+      }
+    }
+  } {}
+}
+
+do_test 1.2 {
+  set x [binary format "ca*" 0 [string range $changeset 1 end]]
+  list [catch { sqlite3changeset_invert $x } msg] $msg
+} {1 SQLITE_CORRUPT}
+
+do_test 1.3 {
+  set x [binary format "ca*" 0 [string range $changeset 1 end]]
+  list [catch { sqlite3changeset_apply db $x xConflict } msg] $msg
+} {1 SQLITE_CORRUPT}
+
+finish_test

ext/session/session5.test

@@ -0,0 +1,409 @@
+# 2011 April 13
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for the session module. 
+# Specifically, for the sqlite3changeset_concat() command.
+# 
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session5
+
+# Organization of tests:
+#
+#   session5-1.*: Simple tests to check the concat() function produces 
+#                 correct results.
+#
+#   session5-2.*: More complicated tests.
+#   
+#   session5-3.*: Schema mismatch errors.
+#
+#   session5-4.*: Test the concat cases that indicate that the database
+#                 was modified in between recording of the two changesets
+#                 being concatenated (i.e. two changesets that INSERT rows
+#                 with the same PK values).
+#
+
+proc do_concat_test {tn args} {
+
+  set subtest 0
+  foreach sql $args {
+    incr subtest
+    sqlite3session S db main ; S attach *
+    execsql $sql
+
+    set c [S changeset]
+    if {[info commands s_prev] != ""} {
+      set c_concat [sqlite3changeset_concat $c_prev $c]
+      set c_two [s_prev changeset]
+      s_prev delete
+
+      set h_concat [changeset_to_list $c_concat]
+      set h_two [changeset_to_list $c_two]
+
+      do_test $tn.$subtest [list set {} $h_concat] $h_two
+    }
+    set c_prev $c
+    rename S s_prev
+  }
+
+  catch { s_prev delete }
+}
+
+#-------------------------------------------------------------------------
+# Test cases session5-1.* - simple tests.
+#
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+}
+
+do_concat_test 1.1.1 {
+  INSERT INTO t1 VALUES(1, 'one');
+} {
+  INSERT INTO t1 VALUES(2, 'two');
+}
+
+do_concat_test 1.1.2 {
+  UPDATE t1 SET b = 'five' WHERE a = 1;
+} {
+  UPDATE t1 SET b = 'six' WHERE a = 2;
+}
+
+do_concat_test 1.1.3 {
+  DELETE FROM t1 WHERE a = 1;
+} {
+  DELETE FROM t1 WHERE a = 2;
+}
+
+
+# 1.2.1:    INSERT + DELETE                     -> (none)
+# 1.2.2:    INSERT + UPDATE                     -> INSERT
+#
+# 1.2.3:    DELETE + INSERT (matching data)     -> (none)
+# 1.2.4:    DELETE + INSERT (non-matching data) -> UPDATE
+#
+# 1.2.5:    UPDATE + UPDATE (matching data)     -> (none)
+# 1.2.6:    UPDATE + UPDATE (non-matching data) -> UPDATE
+# 1.2.7:    UPDATE + DELETE                     -> DELETE
+#
+do_concat_test 1.2.1 {
+  INSERT INTO t1 VALUES('x', 'y');
+} {
+  DELETE FROM t1 WHERE a = 'x';
+}
+do_concat_test 1.2.2 {
+  INSERT INTO t1 VALUES(5.0, 'five');
+} {
+  UPDATE t1 SET b = 'six' WHERE a = 5.0;
+}
+
+do_execsql_test 1.2.3.1 "INSERT INTO t1 VALUES('I', 'one')"
+do_concat_test 1.2.3.2 {
+  DELETE FROM t1 WHERE a = 'I';
+} {
+  INSERT INTO t1 VALUES('I', 'one');
+}
+do_concat_test 1.2.4 {
+  DELETE FROM t1 WHERE a = 'I';
+} {
+  INSERT INTO t1 VALUES('I', 'two');
+}
+do_concat_test 1.2.5 {
+  UPDATE t1 SET b = 'five' WHERE a = 'I';
+} {
+  UPDATE t1 SET b = 'two' WHERE a = 'I';
+}
+do_concat_test 1.2.6 {
+  UPDATE t1 SET b = 'six' WHERE a = 'I';
+} {
+  UPDATE t1 SET b = 'seven' WHERE a = 'I';
+}
+do_concat_test 1.2.7 {
+  UPDATE t1 SET b = 'eight' WHERE a = 'I';
+} {
+  DELETE FROM t1 WHERE a = 'I';
+}
+
+
+#-------------------------------------------------------------------------
+# Test cases session5-2.* - more complex tests.
+#
+db function indirect indirect 
+proc indirect {{x -1}} {
+  S indirect $x
+  s_prev indirect $x
+}
+do_concat_test 2.1 {
+  CREATE TABLE abc(a, b, c PRIMARY KEY);
+  INSERT INTO abc VALUES(NULL, NULL, 1);
+  INSERT INTO abc VALUES('abcdefghijkl', NULL, 2);
+} {
+  DELETE FROM abc WHERE c = 1;
+  UPDATE abc SET c = 1 WHERE c = 2;
+} {
+  INSERT INTO abc VALUES('abcdefghijkl', NULL, 2);
+  INSERT INTO abc VALUES(1.0, 2.0, 3);
+} {
+  UPDATE abc SET a = a-1;
+} {
+  CREATE TABLE def(d, e, f, PRIMARY KEY(e, f));
+  INSERT INTO def VALUES('x', randomblob(11000), 67);
+  INSERT INTO def SELECT d, e, f+1 FROM def;
+  INSERT INTO def SELECT d, e, f+2 FROM def;
+  INSERT INTO def SELECT d, e, f+4 FROM def;
+} {
+  DELETE FROM def WHERE rowid>4;
+} { 
+  INSERT INTO def SELECT d, e, f+4 FROM def; 
+} {
+  INSERT INTO abc VALUES(22, 44, -1);
+} { 
+  UPDATE abc SET c=-2 WHERE c=-1;
+  UPDATE abc SET c=-3 WHERE c=-2;
+} {
+  UPDATE abc SET c=-4 WHERE c=-3;
+} {
+  UPDATE abc SET a=a+1 WHERE c=-3;
+  UPDATE abc SET a=a+1 WHERE c=-3;
+} {
+  UPDATE abc SET a=a+1 WHERE c=-3;
+  UPDATE abc SET a=a+1 WHERE c=-3;
+} {
+  INSERT INTO abc VALUES('one', 'two', 'three');
+} {
+  SELECT indirect(1);
+  UPDATE abc SET a='one point five' WHERE c = 'three';
+} {
+  SELECT indirect(0);
+  UPDATE abc SET a='one point six' WHERE c = 'three';
+} {
+  CREATE TABLE x1(a, b, PRIMARY KEY(a));
+  SELECT indirect(1);
+  INSERT INTO x1 VALUES(1, 2);
+} {
+  SELECT indirect(1);
+  UPDATE x1 SET b = 3 WHERE a = 1;
+}
+
+catch {db close}
+forcedelete test.db
+sqlite3 db test.db
+do_concat_test 2.2 {
+  CREATE TABLE t1(a, b, PRIMARY KEY(b));
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES('string', 1);
+  INSERT INTO t1 VALUES(4, 2);
+  INSERT INTO t1 VALUES(X'FFAAFFAAFFAA', 3);
+} {
+  INSERT INTO t2 VALUES('one', 'two');
+  INSERT INTO t2 VALUES(1, NULL);
+  UPDATE t1 SET a = 5 WHERE a = 2;
+} {
+  DELETE FROM t2 WHERE a = 1;
+  UPDATE t1 SET a = 4 WHERE a = 2;
+  INSERT INTO t2 VALUES('x', 'y');
+}
+
+do_test 2.3.0 {
+  catch {db close}
+  forcedelete test.db
+  sqlite3 db test.db
+ 
+  set sql1 ""
+  set sql2 ""
+  for {set i 1} {$i < 120} {incr i} {
+    append sql1 "INSERT INTO x1 VALUES($i*4, $i);"
+  }
+  for {set i 1} {$i < 120} {incr i} {
+    append sql2 "DELETE FROM x1 WHERE a = $i*4;"
+  }
+  set {} {}
+} {}
+do_concat_test 2.3 {
+  CREATE TABLE x1(a PRIMARY KEY, b)
+} $sql1 $sql2 $sql1 $sql2
+
+do_concat_test 2.4 {
+  CREATE TABLE x2(a PRIMARY KEY, b);
+  CREATE TABLE x3(a PRIMARY KEY, b);
+
+  INSERT INTO x2 VALUES('a', 'b');
+  INSERT INTO x2 VALUES('x', 'y');
+  INSERT INTO x3 VALUES('a', 'b');
+} {
+  INSERT INTO x2 VALUES('c', 'd');
+  INSERT INTO x3 VALUES('e', 'f');
+  INSERT INTO x3 VALUES('x', 'y');
+}
+
+do_concat_test 2.5 {
+  UPDATE x3 SET b = 'Y' WHERE a = 'x'
+} {
+  DELETE FROM x3 WHERE a = 'x'
+} {
+  DELETE FROM x2 WHERE a = 'a'
+} {
+  INSERT INTO x2 VALUES('a', 'B');
+}
+
+for {set k 1} {$k <=10} {incr k} {
+  do_test 2.6.$k.1 {
+    drop_all_tables
+    set sql1 ""
+    set sql2 ""
+    for {set i 1} {$i < 120} {incr i} {
+      append sql1 "INSERT INTO x1 VALUES(randomblob(20+(random()%10)), $i);"
+    }
+    for {set i 1} {$i < 120} {incr i} {
+      append sql2 "DELETE FROM x1 WHERE rowid = $i;"
+    }
+    set {} {}
+  } {}
+  do_concat_test 2.6.$k {
+    CREATE TABLE x1(a PRIMARY KEY, b)
+  } $sql1 $sql2 $sql1 $sql2
+}
+
+for {set k 1} {$k <=10} {incr k} {
+  do_test 2.7.$k.1 {
+    drop_all_tables
+    set sql1 ""
+    set sql2 ""
+    for {set i 1} {$i < 120} {incr i} {
+      append sql1 {
+        INSERT INTO x1 VALUES(
+         CASE WHEN random()%2 THEN random() ELSE randomblob(20+random()%10) END,
+         CASE WHEN random()%2 THEN random() ELSE randomblob(20+random()%10) END
+        );
+      }
+    }
+    for {set i 1} {$i < 120} {incr i} {
+      append sql2 "DELETE FROM x1 WHERE rowid = $i;"
+    }
+    set {} {}
+  } {}
+  do_concat_test 2.7.$k {
+    CREATE TABLE x1(a PRIMARY KEY, b)
+  } $sql1 $sql2 $sql1 $sql2
+}
+
+
+#-------------------------------------------------------------------------
+# Test that schema incompatibilities are detected correctly.
+#
+#   session5-3.1: Incompatible number of columns.
+#   session5-3.2: Incompatible PK definition.
+#
+
+do_test 3.1 {
+  db close
+  forcedelete test.db
+  sqlite3 db test.db
+
+  execsql { CREATE TABLE t1(a PRIMARY KEY, b) }
+  set c1 [changeset_from_sql { INSERT INTO t1 VALUES(1, 2) }]
+  execsql { 
+    DROP TABLE t1;
+    CREATE TABLE t1(a PRIMARY KEY, b, c);
+  }
+  set c2 [changeset_from_sql { INSERT INTO t1 VALUES(2, 3, 4) }]
+
+  list [catch { sqlite3changeset_concat $c1 $c2 } msg] $msg
+} {1 SQLITE_SCHEMA}
+
+do_test 3.2 {
+  db close
+  forcedelete test.db
+  sqlite3 db test.db
+
+  execsql { CREATE TABLE t1(a PRIMARY KEY, b) }
+  set c1 [changeset_from_sql { INSERT INTO t1 VALUES(1, 2) }]
+  execsql { 
+    DROP TABLE t1;
+    CREATE TABLE t1(a, b PRIMARY KEY);
+  }
+  set c2 [changeset_from_sql { INSERT INTO t1 VALUES(2, 3) }]
+
+  list [catch { sqlite3changeset_concat $c1 $c2 } msg] $msg
+} {1 SQLITE_SCHEMA}
+
+#-------------------------------------------------------------------------
+# Test that concat() handles these properly:
+#
+#   session5-4.1: INSERT + INSERT
+#   session5-4.2: UPDATE + INSERT
+#   session5-4.3: DELETE + UPDATE
+#   session5-4.4: DELETE + DELETE
+#
+
+proc do_concat_test2 {tn sql1 sqlX sql2 expected} {
+  sqlite3session S db main ; S attach *
+  execsql $sql1
+  set ::c1 [S changeset]
+  S delete
+
+  execsql $sqlX
+
+  sqlite3session S db main ; S attach *
+  execsql $sql2
+  set ::c2 [S changeset]
+  S delete
+
+  uplevel do_test $tn [list {
+    changeset_to_list [sqlite3changeset_concat $::c1 $::c2]
+  }] [list [normalize_list $expected]]
+}
+
+drop_all_tables db
+do_concat_test2 4.1 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES('key', 'value');
+} {
+  DELETE FROM t1 WHERE a = 'key';
+} {
+  INSERT INTO t1 VALUES('key', 'xxx');
+} {
+  {INSERT t1 0 X. {} {t key t value}}
+}
+do_concat_test2 4.2 {
+  UPDATE t1 SET b = 'yyy';
+} {
+  DELETE FROM t1 WHERE a = 'key';
+} {
+  INSERT INTO t1 VALUES('key', 'value');
+} {
+  {UPDATE t1 0 X. {t key t xxx} {{} {} t yyy}}
+}
+do_concat_test2 4.3 {
+  DELETE FROM t1 WHERE a = 'key';
+} {
+  INSERT INTO t1 VALUES('key', 'www');
+} {
+  UPDATE t1 SET b = 'valueX' WHERE a = 'key';
+} {
+  {DELETE t1 0 X. {t key t value} {}}
+}
+do_concat_test2 4.4 {
+  DELETE FROM t1 WHERE a = 'key';
+} {
+  INSERT INTO t1 VALUES('key', 'ttt');
+} {
+  DELETE FROM t1 WHERE a = 'key';
+} {
+  {DELETE t1 0 X. {t key t valueX} {}}
+}
+
+finish_test
+

ext/session/session6.test

@@ -0,0 +1,90 @@
+# 2011 July 11
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite sessions extension.
+# Specifically, it tests that sessions work when the database is modified
+# using incremental blob handles.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session6
+
+proc do_then_apply_tcl {tcl {dbname main}} {
+  proc xConflict args { return "OMIT" }
+  set rc [catch {
+    sqlite3session S db $dbname
+    db eval "SELECT name FROM $dbname.sqlite_master WHERE type = 'table'" {
+      S attach $name
+    }
+    eval $tcl
+    sqlite3changeset_apply db2 [S changeset] xConflict
+  } msg]
+
+  catch { S delete }
+  if {$rc} {error $msg}
+}
+
+test_sqlite3_log x
+proc x {args} {puts $args}
+
+forcedelete test.db2
+sqlite3 db2 test.db2
+
+do_common_sql {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t2(c PRIMARY KEY, d);
+}
+
+# Test a blob update.
+#
+do_test 1.1 {
+  do_then_apply_tcl {
+    db eval { INSERT INTO t1 VALUES(1, 'helloworld') }
+    db eval { INSERT INTO t2 VALUES(2, 'onetwothree') }
+  }
+  compare_db db db2
+} {}
+do_test 1.2 {
+  do_then_apply_tcl {
+    set fd [db incrblob t1 b 1]
+    puts -nonewline $fd 1234567890
+    close $fd
+  }
+  compare_db db db2
+} {}
+
+# Test an attached database.
+#
+do_test 2.1 {
+  forcedelete test.db3
+  file copy test.db2 test.db3
+  execsql { ATTACH 'test.db3' AS aux; }
+
+  do_then_apply_tcl {
+    set fd [db incrblob aux t2 d 1]
+    puts -nonewline $fd fourfivesix
+    close $fd
+  } aux
+
+  sqlite3 db3 test.db3
+  compare_db db2 db3
+} {}
+
+
+db3 close
+db2 close
+
+finish_test

ext/session/session8.test

@@ -0,0 +1,92 @@
+# 2011 July 13
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix session8
+
+proc noop {args} {}
+
+# Like [dbcksum] in tester.tcl. Except this version is not sensitive
+# to changes in the value of implicit IPK columns.
+#
+proc udbcksum {db dbname} {
+  if {$dbname=="temp"} {
+    set master sqlite_temp_master
+  } else {
+    set master $dbname.sqlite_master
+  }
+  set alltab [$db eval "SELECT name FROM $master WHERE type='table'"]
+  set txt [$db eval "SELECT * FROM $master"]\n
+  foreach tab $alltab {
+    append txt [lsort [$db eval "SELECT * FROM $dbname.$tab"]]\n
+  }
+  return [md5 $txt]
+}
+
+proc do_then_undo {tn sql} {
+  set ck1 [udbcksum db main]
+
+  sqlite3session S db main
+  S attach *
+  db eval $sql
+
+  set ck2 [udbcksum db main]
+  
+  set invert [sqlite3changeset_invert [S changeset]]
+  S delete
+  sqlite3changeset_apply db $invert noop
+
+  set ck3 [udbcksum db main]
+
+  set a [expr {$ck1==$ck2}]
+  set b [expr {$ck1==$ck3}]
+  uplevel [list do_test $tn.1 "set {} $a" 0]
+  uplevel [list do_test $tn.2 "set {} $b" 1]
+}
+
+do_execsql_test 1.1 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES(1, 2);
+  INSERT INTO t1 VALUES("abc", "xyz");
+}
+do_then_undo 1.2 { INSERT INTO t1 VALUES(3, 4); }
+do_then_undo 1.3 { DELETE FROM t1 WHERE b=2; }
+do_then_undo 1.4 { UPDATE t1 SET b = 3 WHERE a = 1; }
+
+do_execsql_test 2.1 {
+  CREATE TABLE t2(a, b PRIMARY KEY);
+  INSERT INTO t2 VALUES(1, 2);
+  INSERT INTO t2 VALUES('abc', 'xyz');
+}
+do_then_undo 1.2 { INSERT INTO t2 VALUES(3, 4); }
+do_then_undo 1.3 { DELETE FROM t2 WHERE b=2; }
+do_then_undo 1.4 { UPDATE t1 SET a = '123' WHERE b = 'xyz'; }
+
+do_execsql_test 3.1 {
+  CREATE TABLE t3(a, b, c, d, e, PRIMARY KEY(c, e));
+  INSERT INTO t3 VALUES('x', 45, 0.0, 'abcdef', 12);
+  INSERT INTO t3 VALUES(45, 0.0, 'abcdef', 12, 'x');
+  INSERT INTO t3 VALUES(0.0, 'abcdef', 12, 'x', 45);
+}
+
+do_then_undo 3.2 { UPDATE t3 SET b=b||b WHERE e!='x' }
+do_then_undo 3.3 { UPDATE t3 SET a = 46 }
+
+finish_test
+

ext/session/session9.test

@@ -0,0 +1,254 @@
+# 2013 July 04
+#
+# 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 tests that the sessions module handles foreign key constraint
+# violations when applying changesets as required.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+set testprefix session9
+
+
+#--------------------------------------------------------------------
+# Basic tests.
+#
+proc populate_db {} {
+  drop_all_tables
+  execsql {
+    PRAGMA foreign_keys = 1;
+    CREATE TABLE p1(a PRIMARY KEY, b);
+    CREATE TABLE c1(a PRIMARY KEY, b REFERENCES p1);
+    CREATE TABLE c2(a PRIMARY KEY, 
+        b REFERENCES p1 DEFERRABLE INITIALLY DEFERRED
+    );
+
+    INSERT INTO p1 VALUES(1, 'one');
+    INSERT INTO p1 VALUES(2, 'two');
+    INSERT INTO p1 VALUES(3, 'three');
+    INSERT INTO p1 VALUES(4, 'four');
+  }
+}
+
+proc capture_changeset {sql} {
+  sqlite3session S db main
+
+  foreach t [db eval {SELECT name FROM sqlite_master WHERE type='table'}] {
+    S attach $t
+  }
+  execsql $sql
+  set ret [S changeset]
+  S delete
+
+  return $ret
+}
+
+do_test 1.1 {
+  populate_db
+  set cc [capture_changeset {
+    INSERT INTO c1 VALUES('ii', 2);
+    INSERT INTO c2 VALUES('iii', 3);
+  }]
+  set {} {}
+} {}
+
+proc xConflict {args} {
+  lappend ::xConflict {*}$args
+  return $::conflictret
+}
+
+foreach {tn delrow trans conflictargs conflictret} {
+  1   2 0 {FOREIGN_KEY 1} OMIT
+  2   3 0 {FOREIGN_KEY 1} OMIT
+  3   2 1 {FOREIGN_KEY 1} OMIT
+  4   3 1 {FOREIGN_KEY 1} OMIT
+  5   2 0 {FOREIGN_KEY 1} ABORT
+  6   3 0 {FOREIGN_KEY 1} ABORT
+  7   2 1 {FOREIGN_KEY 1} ABORT
+  8   3 1 {FOREIGN_KEY 1} ABORT
+} {
+
+  set A(OMIT)  {0 {}}
+  set A(ABORT) {1 SQLITE_CONSTRAINT}
+  do_test 1.2.$tn.1 {
+    populate_db
+    execsql { DELETE FROM p1 WHERE a=($delrow+0) }
+    if {$trans} { execsql BEGIN }
+
+    set ::xConflict [list]
+    list [catch {sqlite3changeset_apply db $::cc xConflict} msg] $msg
+  } $A($conflictret)
+
+  do_test 1.2.$tn.2 { set ::xConflict } $conflictargs
+
+  set A(OMIT)  {1 1}
+  set A(ABORT) {0 0}
+  do_test 1.2.$tn.3 {
+    execsql { SELECT count(*) FROM c1 UNION ALL SELECT count(*) FROM c2 }
+  } $A($conflictret)
+
+  do_test 1.2.$tn.4 { expr ![sqlite3_get_autocommit db] } $trans
+  do_test 1.2.$tn.5 {
+    if { $trans } { execsql COMMIT }
+  } {}
+}
+
+#--------------------------------------------------------------------
+# Test that closing a transaction clears the defer_foreign_keys flag.
+#
+foreach {tn open noclose close} {
+  1 BEGIN {} COMMIT
+  2 BEGIN {} ROLLBACK
+
+  3 {SAVEPOINT one} {}                {RELEASE one}
+  4 {SAVEPOINT one} {ROLLBACK TO one} {RELEASE one}
+} {
+  execsql $open
+  do_execsql_test 2.$tn.1 { PRAGMA defer_foreign_keys } {0}
+
+  do_execsql_test 2.$tn.2 {
+    PRAGMA defer_foreign_keys = 1;
+    PRAGMA defer_foreign_keys;
+  } {1}
+
+  execsql $noclose
+  do_execsql_test 2.$tn.3 { PRAGMA defer_foreign_keys } {1}
+
+  execsql $close
+  do_execsql_test 2.$tn.4 { PRAGMA defer_foreign_keys } {0}
+}
+
+#--------------------------------------------------------------------
+# Test that a cyclic relationship can be inserted and deleted.
+#
+# This situation does not come up in practice, but testing it serves to 
+# show that it does not matter which order parent and child keys 
+# are processed in internally when applying a changeset.
+#
+drop_all_tables
+
+do_execsql_test 3.1 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t2(x PRIMARY KEY, y);
+}
+
+# Create changesets as follows:
+# 
+#   $cc1    - Insert a row into t1.
+#   $cc2    - Insert a row into t2.
+#   $cc     - Combination of $cc1 and $cc2.
+#
+#   $ccdel1 - Delete the row from t1.
+#   $ccdel2 - Delete the row from t2.
+#   $ccdel  - Combination of $cc1 and $cc2.
+#
+do_test 3.2 {
+  set cc1 [capture_changeset {
+    INSERT INTO t1 VALUES('one', 'value one');
+  }]
+  set ccdel1 [capture_changeset { DELETE FROM t1; }]
+  set cc2 [capture_changeset {
+    INSERT INTO t2 VALUES('value one', 'one');
+  }]
+  set ccdel2 [capture_changeset { DELETE FROM t2; }]
+  set cc [capture_changeset {
+    INSERT INTO t1 VALUES('one', 'value one');
+    INSERT INTO t2 VALUES('value one', 'one');
+  }]
+  set ccdel [capture_changeset {
+    DELETE FROM t1;
+    DELETE FROM t2;
+  }]
+  set {} {}
+} {}
+
+# Now modify the database schema to create a cyclic foreign key dependency
+# between tables t1 and t2. This means that although changesets $cc and
+# $ccdel can be applied, none of the others may without violating the
+# foreign key constraints. 
+# 
+do_test 3.3 {
+
+  drop_all_tables
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b REFERENCES t2);
+    CREATE TABLE t2(x PRIMARY KEY, y REFERENCES t1);
+  }
+
+
+  proc conflict_handler {args} { return "ABORT" }
+  sqlite3changeset_apply db $cc conflict_handler
+
+  execsql {
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+  }
+} {one {value one} {value one} one}
+
+do_test 3.3.1 {
+  list [catch {sqlite3changeset_apply db $::ccdel1 conflict_handler} msg] $msg
+} {1 SQLITE_CONSTRAINT}
+do_test 3.3.2 {
+  list [catch {sqlite3changeset_apply db $::ccdel2 conflict_handler} msg] $msg
+} {1 SQLITE_CONSTRAINT}
+
+do_test 3.3.4.1 {
+  list [catch {sqlite3changeset_apply db $::ccdel conflict_handler} msg] $msg
+} {0 {}}
+do_execsql_test 3.3.4.2 {
+  SELECT * FROM t1;
+  SELECT * FROM t2;
+} {}
+
+do_test 3.5.1 {
+  list [catch {sqlite3changeset_apply db $::cc1 conflict_handler} msg] $msg
+} {1 SQLITE_CONSTRAINT}
+do_test 3.5.2 {
+  list [catch {sqlite3changeset_apply db $::cc2 conflict_handler} msg] $msg
+} {1 SQLITE_CONSTRAINT}
+
+#--------------------------------------------------------------------
+# Test that if a change that affects FK processing is not applied 
+# due to a separate constraint, SQLite does not get confused and
+# increment FK counters anyway.
+#
+drop_all_tables
+do_execsql_test 4.1 {
+  CREATE TABLE p1(x PRIMARY KEY, y);
+  CREATE TABLE c1(a PRIMARY KEY, b REFERENCES p1);
+  INSERT INTO p1 VALUES(1,1);
+}
+
+do_execsql_test 4.2.1 {
+  BEGIN;
+    PRAGMA defer_foreign_keys = 1;
+    INSERT INTO c1 VALUES('x', 'x');
+}
+do_catchsql_test 4.2.2 { COMMIT } {1 {FOREIGN KEY constraint failed}}
+do_catchsql_test 4.2.3 { ROLLBACK } {0 {}}
+
+do_execsql_test 4.3.1 {
+  BEGIN;
+    PRAGMA defer_foreign_keys = 1;
+    INSERT INTO c1 VALUES(1, 1);
+}
+do_catchsql_test 4.3.2 { 
+  INSERT INTO c1 VALUES(1, 'x') 
+} {1 {UNIQUE constraint failed: c1.a}}
+
+do_catchsql_test 4.3.3 { COMMIT } {0 {}}
+do_catchsql_test 4.3.4 { BEGIN ; COMMIT } {0 {}}
+
+finish_test

ext/session/sessionA.test

@@ -0,0 +1,69 @@
+# 2013 July 04
+#
+# 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 tests that the sessions module handles foreign key constraint
+# violations when applying changesets as required.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+set testprefix sessionA
+
+
+forcedelete test.db2
+sqlite3 db2 test.db2
+foreach {tn db} {1 db 2 db2} {
+  do_test 1.$tn.1 {
+    execsql {
+      CREATE TABLE t1(a PRIMARY KEY, b);
+      CREATE TABLE t2(a PRIMARY KEY, b);
+      CREATE TABLE t3(a PRIMARY KEY, b);
+    } $db
+  } {}
+}
+
+proc tbl_filter {zTbl} {
+  return $::table_filter($zTbl)
+}
+
+do_test 2.1 {
+  set ::table_filter(t1) 1
+  set ::table_filter(t2) 0
+  set ::table_filter(t3) 1
+
+  sqlite3session S db main
+  S table_filter tbl_filter 
+
+  execsql {
+    INSERT INTO t1 VALUES('a', 'b');
+    INSERT INTO t2 VALUES('c', 'd');
+    INSERT INTO t3 VALUES('e', 'f');
+  }
+
+  set changeset [S changeset]
+  S delete
+  sqlite3changeset_apply db2 $changeset xConflict
+
+  execsql {
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+    SELECT * FROM t3;
+  } db2
+} {a b e f}
+
+
+finish_test
+
+

ext/session/session_common.tcl

@@ -0,0 +1,136 @@
+
+
+proc do_conflict_test {tn args} {
+  proc xConflict {args} { 
+    lappend ::xConflict $args
+    return "" 
+  }
+  proc bgerror {args} { set ::background_error $args }
+
+
+  set O(-tables)    [list]
+  set O(-sql)       [list]
+  set O(-conflicts) [list]
+
+  array set V $args
+  foreach key [array names V] {
+    if {![info exists O($key)]} {error "no such option: $key"}
+  }
+  array set O $args
+
+  sqlite3session S db main
+  foreach t $O(-tables) { S attach $t }
+  execsql $O(-sql)
+
+  set ::xConflict [list]
+  sqlite3changeset_apply db2 [S changeset] xConflict
+
+  set conflicts [list]
+  foreach c $O(-conflicts) {
+    lappend conflicts $c
+  }
+
+  after 1 {set go 1}
+  vwait go
+
+  uplevel do_test $tn [list { set ::xConflict }] [list $conflicts]
+  S delete
+}
+
+proc do_common_sql {sql} {
+  execsql $sql db
+  execsql $sql db2
+}
+
+proc changeset_from_sql {sql {dbname main}} {
+  set rc [catch {
+    sqlite3session S db $dbname
+    db eval "SELECT name FROM $dbname.sqlite_master WHERE type = 'table'" {
+      S attach $name
+    }
+    db eval $sql
+    S changeset
+  } changeset]
+  catch { S delete }
+
+  if {$rc} {
+    error $changeset
+  }
+  return $changeset
+}
+
+proc do_then_apply_sql {sql {dbname main}} {
+  proc xConflict args { return "OMIT" }
+  set rc [catch {
+    sqlite3session S db $dbname
+    db eval "SELECT name FROM $dbname.sqlite_master WHERE type = 'table'" {
+      S attach $name
+    }
+    db eval $sql
+    sqlite3changeset_apply db2 [S changeset] xConflict
+  } msg]
+
+  catch { S delete }
+
+  if {$rc} {error $msg}
+}
+
+proc do_iterator_test {tn tbl_list sql res} {
+  sqlite3session S db main
+  if {[llength $tbl_list]==0} { S attach * }
+  foreach t $tbl_list {S attach $t}
+
+  execsql $sql
+
+  set r [list]
+  foreach v $res { lappend r $v }
+
+  set x [list]
+  sqlite3session_foreach c [S changeset] { lappend x $c }
+  uplevel do_test $tn [list [list set {} $x]] [list $r]
+
+  S delete
+}
+
+# Compare the contents of all tables in [db1] and [db2]. Throw an error if 
+# they are not identical, or return an empty string if they are.
+#
+proc compare_db {db1 db2} {
+
+  set sql {SELECT name FROM sqlite_master WHERE type = 'table' ORDER BY name}
+  set lot1 [$db1 eval $sql]
+  set lot2 [$db2 eval $sql]
+
+  if {$lot1 != $lot2} { 
+    puts $lot1
+    puts $lot2
+    error "databases contain different tables" 
+  }
+
+  foreach tbl $lot1 {
+    set col1 [list]
+    set col2 [list]
+
+    $db1 eval "PRAGMA table_info = $tbl" { lappend col1 $name }
+    $db2 eval "PRAGMA table_info = $tbl" { lappend col2 $name }
+    if {$col1 != $col2} { error "table $tbl schema mismatch" }
+
+    set sql "SELECT * FROM $tbl ORDER BY [join $col1 ,]"
+    set data1 [$db1 eval $sql]
+    set data2 [$db2 eval $sql]
+    if {$data1 != $data2} { 
+      puts "$data1"
+      puts "$data2"
+      error "table $tbl data mismatch" 
+    }
+  }
+
+  return ""
+}
+
+proc changeset_to_list {c} {
+  set list [list]
+  sqlite3session_foreach elem $c { lappend list $elem }
+  lsort $list
+}
+

ext/session/sessionfault.test

@@ -0,0 +1,443 @@
+# 2011 Mar 21
+#
+# 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.
+#
+#***********************************************************************
+#
+# The focus of this file is testing the session module.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+
+set testprefix sessionfault
+
+if 1 {
+
+forcedelete test.db2
+sqlite3 db2 test.db2
+do_common_sql {
+  CREATE TABLE t1(a, b, c, PRIMARY KEY(a, b));
+  INSERT INTO t1 VALUES(1, 2, 3);
+  INSERT INTO t1 VALUES(4, 5, 6);
+}
+faultsim_save_and_close
+db2 close
+
+
+#-------------------------------------------------------------------------
+# Test OOM error handling when collecting and applying a simple changeset.
+#
+# Test 1.1 attaches tables individually by name to the session object. 
+# Whereas test 1.2 passes NULL to sqlite3session_attach() to attach all
+# tables.
+#
+do_faultsim_test 1.1 -faults oom-* -prep {
+  catch {db2 close}
+  catch {db close}
+  faultsim_restore_and_reopen
+  sqlite3 db2 test.db2
+} -body {
+  do_then_apply_sql {
+    INSERT INTO t1 VALUES('a string value', 8, 9);
+    UPDATE t1 SET c = 10 WHERE a = 1;
+    DELETE FROM t1 WHERE a = 4;
+  }
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  faultsim_integrity_check
+  if {$testrc==0} { compare_db db db2 }
+}
+
+do_faultsim_test 1.2 -faults oom-* -prep {
+  catch {db2 close}
+  catch {db close}
+  faultsim_restore_and_reopen
+} -body {
+  sqlite3session S db main
+  S attach *
+  execsql {
+    INSERT INTO t1 VALUES('a string value', 8, 9);
+    UPDATE t1 SET c = 10 WHERE a = 1;
+    DELETE FROM t1 WHERE a = 4;
+  }
+  set ::changeset [S changeset]
+  set {} {}
+} -test {
+  catch { S delete }
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  faultsim_integrity_check
+  if {$testrc==0} { 
+    proc xConflict {args} { return "OMIT" }
+    sqlite3 db2 test.db2
+    sqlite3changeset_apply db2 $::changeset xConflict
+    compare_db db db2 
+  }
+}
+
+#-------------------------------------------------------------------------
+# The following block of tests - 2.* - are designed to check 
+# the handling of faults in the sqlite3changeset_apply() function.
+#
+catch {db close}
+catch {db2 close}
+forcedelete test.db2 test.db
+sqlite3 db2 test.db2
+sqlite3 db test.db
+do_common_sql {
+  CREATE TABLE t1(a, b, c, PRIMARY KEY(a, b));
+  INSERT INTO t1 VALUES('apple', 'orange', 'pear');
+
+  CREATE TABLE t2(x PRIMARY KEY, y);
+}
+db2 close
+faultsim_save_and_close
+
+
+foreach {tn conflict_policy sql sql2} {
+  1 OMIT { INSERT INTO t1 VALUES('one text', 'two text', X'00ff00') } {}
+  2 OMIT { DELETE FROM t1 WHERE a = 'apple' }                         {}
+  3 OMIT { UPDATE t1 SET c = 'banana' WHERE b = 'orange' }            {}
+  4 REPLACE { INSERT INTO t2 VALUES('keyvalue', 'value 1') } {
+    INSERT INTO t2 VALUES('keyvalue', 'value 2');
+  }
+} {
+  proc xConflict args [list return $conflict_policy]
+
+  do_faultsim_test 2.$tn -faults oom-transient -prep {
+    catch {db2 close}
+    catch {db close}
+    faultsim_restore_and_reopen
+    set ::changeset [changeset_from_sql $::sql]
+    sqlite3 db2 test.db2
+    sqlite3_db_config_lookaside db2 0 0 0
+    execsql $::sql2 db2
+  } -body {
+    sqlite3changeset_apply db2 $::changeset xConflict
+  } -test {
+    faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+    faultsim_integrity_check
+    if {$testrc==0} { compare_db db db2 }
+  }
+}
+
+#-------------------------------------------------------------------------
+# This test case is designed so that a malloc() failure occurs while
+# resizing the session object hash-table from 256 to 512 buckets. This
+# is not an error, just a sub-optimal condition.
+#
+do_faultsim_test 3 -faults oom-* -prep {
+  catch {db2 close}
+  catch {db close}
+  faultsim_restore_and_reopen
+  sqlite3 db2 test.db2
+
+  sqlite3session S db main
+  S attach t1
+  execsql { BEGIN }
+  for {set i 0} {$i < 125} {incr i} {
+    execsql {INSERT INTO t1 VALUES(10+$i, 10+$i, 10+$i)}
+  }
+} -body {
+  for {set i 125} {$i < 133} {incr i} {
+    execsql {INSERT INTO t1 VALUES(10+$i, 10+$i, 1-+$i)}
+  }
+  S changeset
+  set {} {}
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} { 
+    sqlite3changeset_apply db2 [S changeset] xConflict
+    compare_db db db2 
+  }
+  catch { S delete }
+  faultsim_integrity_check
+}
+
+catch { db close }
+catch { db2 close }
+forcedelete test.db2 test.db
+sqlite3 db2 test.db2
+sqlite3 db test.db
+
+proc xConflict {op tbl type args} {
+  if { $type=="CONFLICT" || $type=="DATA" } {
+    return "REPLACE"
+  }
+  return "OMIT"
+}
+
+do_test 4.0 {
+  execsql {
+    PRAGMA encoding = 'utf16';
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    INSERT INTO t1 VALUES(5, 32);
+  }
+  execsql {
+    PRAGMA encoding = 'utf16';
+    CREATE TABLE t1(a PRIMARY KEY, b NOT NULL);
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(2, 4);
+    INSERT INTO t1 VALUES(4, 16);
+  } db2
+} {}
+
+faultsim_save_and_close
+db2 close
+
+do_faultsim_test 4 -faults oom-* -prep {
+  catch {db2 close}
+  catch {db close}
+  faultsim_restore_and_reopen
+  sqlite3 db2 test.db2
+  sqlite3session S db main
+  S attach t1
+  execsql {
+    INSERT INTO t1 VALUES(1, 45);
+    INSERT INTO t1 VALUES(2, 55);
+    INSERT INTO t1 VALUES(3, 55);
+    UPDATE t1 SET a = 4 WHERE a = 5;
+  }
+} -body {
+  sqlite3changeset_apply db2 [S changeset] xConflict
+} -test {
+  catch { S delete }
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} { compare_db db db2 }
+}
+
+#-------------------------------------------------------------------------
+# This block of tests verifies that OOM faults in the 
+# sqlite3changeset_invert() function are handled correctly.
+#
+catch {db close}
+catch {db2 close}
+forcedelete test.db
+sqlite3 db test.db
+execsql {
+  CREATE TABLE t1(a, b, PRIMARY KEY(b));
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES('string', 1);
+  INSERT INTO t1 VALUES(4, 2);
+  INSERT INTO t1 VALUES(X'FFAAFFAAFFAA', 3);
+}
+set changeset [changeset_from_sql {
+  INSERT INTO t1 VALUES('xxx', 'yyy');
+  DELETE FROM t1 WHERE a = 'string';
+  UPDATE t1 SET a = 20 WHERE b = 2;
+}]
+db close
+
+do_faultsim_test 5 -faults oom* -body {
+  set ::inverse [sqlite3changeset_invert $::changeset]
+  set {} {}
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} {
+    set x [list]
+    sqlite3session_foreach c $::inverse { lappend x $c }
+    foreach c {
+        {DELETE t1 0 .X {t xxx t yyy} {}} 
+        {INSERT t1 0 .X {} {t string i 1}} 
+        {UPDATE t1 0 .X {i 20 i 2} {i 4 {} {}}}
+    } { lappend y $c }
+    if {$x != $y} { error "changeset no good" }
+  }
+}
+
+#-------------------------------------------------------------------------
+# Test that OOM errors in sqlite3changeset_concat() are handled correctly.
+#
+catch {db close}
+forcedelete test.db
+sqlite3 db test.db
+do_execsql_test 5.prep1 {
+  CREATE TABLE t1(a, b, PRIMARY KEY(b));
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t1 VALUES('string', 1);
+  INSERT INTO t1 VALUES(4, 2);
+  INSERT INTO t1 VALUES(X'FFAAFFAAFFAA', 3);
+}
+
+do_test 6.prep2 {
+  sqlite3session M db main
+  M attach *
+  set ::c2 [changeset_from_sql {
+    INSERT INTO t2 VALUES(randomblob(1000), randomblob(1000));
+    INSERT INTO t2 VALUES('one', 'two');
+    INSERT INTO t2 VALUES(1, NULL);
+    UPDATE t1 SET a = 5 WHERE a = 2;
+  }]
+  set ::c1 [changeset_from_sql {
+    DELETE FROM t2 WHERE a = 1;
+    UPDATE t1 SET a = 4 WHERE a = 2;
+    INSERT INTO t2 VALUES('x', 'y');
+  }]
+  set ::total [changeset_to_list [M changeset]]
+  M delete
+} {}
+
+do_faultsim_test 6 -faults oom-* -body {
+  set ::result [sqlite3changeset_concat $::c1 $::c2]
+  set {} {}
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} {
+    set v [changeset_to_list $::result]
+    if {$v != $::total} { error "result no good" }
+  }
+}
+
+faultsim_delete_and_reopen
+do_execsql_test 5.prep1 {
+  CREATE TABLE t1(a, b, PRIMARY KEY(a));
+}
+faultsim_save_and_close
+
+set res [list]
+for {set ::i 0} {$::i < 480} {incr ::i 4} {
+  lappend res "INSERT t1 0 X. {} {i $::i i $::i}"
+}
+set res [lsort $res]
+do_faultsim_test 7 -faults oom-transient -prep {
+  faultsim_restore_and_reopen
+  sqlite3session S db main
+  S attach *
+} -body {
+  for {set ::i 0} {$::i < 480} {incr ::i 4} {
+    execsql {INSERT INTO t1 VALUES($::i, $::i)}
+  }
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} {
+    set cres [list [catch {changeset_to_list [S changeset]} msg] $msg]
+    S delete
+    if {$cres != "1 SQLITE_NOMEM" && $cres != "0 {$::res}"} {
+      error "Expected {0 $::res} Got {$cres}"
+    }
+  } else {
+    S changeset
+    S delete
+  }
+}
+
+faultsim_delete_and_reopen
+do_test 8.prep {
+  sqlite3session S db main
+  S attach *
+  execsql { 
+    CREATE TABLE t1(a, b, PRIMARY KEY(a)); 
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t1 VALUES(3, 4);
+    INSERT INTO t1 VALUES(5, 6);
+  }
+  set ::changeset [S changeset]
+  S delete
+} {}
+
+set expected [normalize_list {
+  {INSERT t1 0 X. {} {i 1 i 2}} 
+  {INSERT t1 0 X. {} {i 3 i 4}} 
+  {INSERT t1 0 X. {} {i 5 i 6}}
+}]
+do_faultsim_test 8.1 -faults oom* -body {
+  set ::res [list]
+  sqlite3session_foreach -next v $::changeset { lappend ::res $v }
+  normalize_list $::res
+} -test {
+  faultsim_test_result [list 0 $::expected] {1 SQLITE_NOMEM}
+}
+do_faultsim_test 8.2 -faults oom* -body {
+  set ::res [list]
+  sqlite3session_foreach v $::changeset { lappend ::res $v }
+  normalize_list $::res
+} -test {
+  faultsim_test_result [list 0 $::expected] {1 SQLITE_NOMEM}
+}
+
+faultsim_delete_and_reopen
+do_test 9.1.prep {
+  execsql { 
+    PRAGMA encoding = 'utf16';
+    CREATE TABLE t1(a PRIMARY KEY, b);
+  }
+} {}
+faultsim_save_and_close
+
+set answers [list {0 {}} {1 SQLITE_NOMEM} \
+                  {1 {callback requested query abort}} \
+                  {1 {abort due to ROLLBACK}}]
+do_faultsim_test 9.1 -faults oom-transient -prep {
+  catch { unset ::c }
+  faultsim_restore_and_reopen
+  sqlite3session S db main
+  S attach *
+} -body {
+  execsql {
+    INSERT INTO t1 VALUES('abcdefghijklmnopqrstuv', 'ABCDEFGHIJKLMNOPQRSTUV');
+  }
+  set ::c [S changeset]
+  set {} {}
+} -test {
+  S delete
+  eval faultsim_test_result $::answers
+  if {[info exists ::c]} {
+    set expected [normalize_list {
+      {INSERT t1 0 X. {} {t abcdefghijklmnopqrstuv t ABCDEFGHIJKLMNOPQRSTUV}}
+    }]
+    if { [changeset_to_list $::c] != $expected } {
+      error "changeset mismatch"
+    }
+  }
+}
+
+}
+
+faultsim_delete_and_reopen
+do_test 9.2.prep {
+  execsql { 
+    PRAGMA encoding = 'utf16';
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    INSERT INTO t1 VALUES('abcdefghij', 'ABCDEFGHIJKLMNOPQRSTUV');
+  }
+} {}
+faultsim_save_and_close
+
+set answers [list {0 {}} {1 SQLITE_NOMEM} \
+                  {1 {callback requested query abort}} \
+                  {1 {abort due to ROLLBACK}}]
+do_faultsim_test 9.2 -faults oom-transient -prep {
+  catch { unset ::c }
+  faultsim_restore_and_reopen
+  sqlite3session S db main
+  S attach *
+} -body {
+  execsql {
+    UPDATE t1 SET b = 'xyz';
+  }
+  set ::c [S changeset]
+  set {} {}
+} -test {
+  S delete
+  eval faultsim_test_result $::answers
+  if {[info exists ::c]} {
+    set expected [normalize_list {
+      {UPDATE t1 0 X. {t abcdefghij t ABCDEFGHIJKLMNOPQRSTUV} {{} {} t xyz}}
+    }]
+    if { [changeset_to_list $::c] != $expected } {
+      error "changeset mismatch"
+    }
+  }
+}
+
+
+
+finish_test

ext/session/sqlite3session.h

@@ -0,0 +1,918 @@
+
+#ifndef __SQLITESESSION_H_
+#define __SQLITESESSION_H_ 1
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "sqlite3.h"
+
+/*
+** CAPI3REF: Session Object Handle
+*/
+typedef struct sqlite3_session sqlite3_session;
+
+/*
+** CAPI3REF: Changeset Iterator Handle
+*/
+typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
+
+/*
+** CAPI3REF: Create A New Session Object
+**
+** Create a new session object attached to database handle db. If successful,
+** a pointer to the new object is written to *ppSession and SQLITE_OK is
+** returned. If an error occurs, *ppSession is set to NULL and an SQLite
+** error code (e.g. SQLITE_NOMEM) is returned.
+**
+** It is possible to create multiple session objects attached to a single
+** database handle.
+**
+** Session objects created using this function should be deleted using the
+** [sqlite3session_delete()] function before the database handle that they
+** are attached to is itself closed. If the database handle is closed before
+** the session object is deleted, then the results of calling any session
+** module function, including [sqlite3session_delete()] on the session object
+** are undefined.
+**
+** Because the session module uses the [sqlite3_preupdate_hook()] API, it
+** is not possible for an application to register a pre-update hook on a
+** database handle that has one or more session objects attached. Nor is
+** it possible to create a session object attached to a database handle for
+** which a pre-update hook is already defined. The results of attempting 
+** either of these things are undefined.
+**
+** The session object will be used to create changesets for tables in
+** database zDb, where zDb is either "main", or "temp", or the name of an
+** attached database. It is not an error if database zDb is not attached
+** to the database when the session object is created.
+*/
+int sqlite3session_create(
+  sqlite3 *db,                    /* Database handle */
+  const char *zDb,                /* Name of db (e.g. "main") */
+  sqlite3_session **ppSession     /* OUT: New session object */
+);
+
+/*
+** CAPI3REF: Delete A Session Object
+**
+** Delete a session object previously allocated using 
+** [sqlite3session_create()]. Once a session object has been deleted, the
+** results of attempting to use pSession with any other session module
+** function are undefined.
+**
+** Session objects must be deleted before the database handle to which they
+** are attached is closed. Refer to the documentation for 
+** [sqlite3session_create()] for details.
+*/
+void sqlite3session_delete(sqlite3_session *pSession);
+
+
+/*
+** CAPI3REF: Enable Or Disable A Session Object
+**
+** Enable or disable the recording of changes by a session object. When
+** enabled, a session object records changes made to the database. When
+** disabled - it does not. A newly created session object is enabled.
+** Refer to the documentation for [sqlite3session_changeset()] for further
+** details regarding how enabling and disabling a session object affects
+** the eventual changesets.
+**
+** Passing zero to this function disables the session. Passing a value
+** greater than zero enables it. Passing a value less than zero is a 
+** no-op, and may be used to query the current state of the session.
+**
+** The return value indicates the final state of the session object: 0 if 
+** the session is disabled, or 1 if it is enabled.
+*/
+int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
+
+/*
+** CAPI3REF: Set Or Clear the Indirect Change Flag
+**
+** Each change recorded by a session object is marked as either direct or
+** indirect. A change is marked as indirect if either:
+**
+** <ul>
+**   <li> The session object "indirect" flag is set when the change is
+**        made, or
+**   <li> The change is made by an SQL trigger or foreign key action 
+**        instead of directly as a result of a users SQL statement.
+** </ul>
+**
+** If a single row is affected by more than one operation within a session,
+** then the change is considered indirect if all operations meet the criteria
+** for an indirect change above, or direct otherwise.
+**
+** This function is used to set, clear or query the session object indirect
+** flag.  If the second argument passed to this function is zero, then the
+** indirect flag is cleared. If it is greater than zero, the indirect flag
+** is set. Passing a value less than zero does not modify the current value
+** of the indirect flag, and may be used to query the current state of the 
+** indirect flag for the specified session object.
+**
+** The return value indicates the final state of the indirect flag: 0 if 
+** it is clear, or 1 if it is set.
+*/
+int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
+
+/*
+** CAPI3REF: Attach A Table To A Session Object
+**
+** If argument zTab is not NULL, then it is the name of a table to attach
+** to the session object passed as the first argument. All subsequent changes 
+** made to the table while the session object is enabled will be recorded. See 
+** documentation for [sqlite3session_changeset()] for further details.
+**
+** Or, if argument zTab is NULL, then changes are recorded for all tables
+** in the database. If additional tables are added to the database (by 
+** executing "CREATE TABLE" statements) after this call is made, changes for 
+** the new tables are also recorded.
+**
+** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
+** defined as part of their CREATE TABLE statement. It does not matter if the 
+** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
+** KEY may consist of a single column, or may be a composite key.
+** 
+** It is not an error if the named table does not exist in the database. Nor
+** is it an error if the named table does not have a PRIMARY KEY. However,
+** no changes will be recorded in either of these scenarios.
+**
+** Changes are not recorded for individual rows that have NULL values stored
+** in one or more of their PRIMARY KEY columns.
+**
+** SQLITE_OK is returned if the call completes without error. Or, if an error 
+** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
+*/
+int sqlite3session_attach(
+  sqlite3_session *pSession,      /* Session object */
+  const char *zTab                /* Table name */
+);
+
+/*
+** CAPI3REF: Set a table filter on a Session Object.
+**
+** The second argument (xFilter) is the "filter callback". For changes to rows 
+** in tables that are not attached to the Session oject, the filter is called
+** to determine whether changes to the table's rows should be tracked or not. 
+** If xFilter returns 0, changes is not tracked. Note that once a table is 
+** attached, xFilter will not be called again.
+*/
+void sqlite3session_table_filter(
+  sqlite3_session *pSession,      /* Session object */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of third arg to _filter_table() */
+    const char *zTab              /* Table name */
+  ),
+  void *pCtx                      /* First argument passed to xFilter */
+);
+
+/*
+** CAPI3REF: Generate A Changeset From A Session Object
+**
+** Obtain a changeset containing changes to the tables attached to the 
+** session object passed as the first argument. If successful, 
+** set *ppChangeset to point to a buffer containing the changeset 
+** and *pnChangeset to the size of the changeset in bytes before returning
+** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
+** zero and return an SQLite error code.
+**
+** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
+** each representing a change to a single row of an attached table. An INSERT
+** change contains the values of each field of a new database row. A DELETE
+** contains the original values of each field of a deleted database row. An
+** UPDATE change contains the original values of each field of an updated
+** database row along with the updated values for each updated non-primary-key
+** column. It is not possible for an UPDATE change to represent a change that
+** modifies the values of primary key columns. If such a change is made, it
+** is represented in a changeset as a DELETE followed by an INSERT.
+**
+** Changes are not recorded for rows that have NULL values stored in one or 
+** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
+** no corresponding change is present in the changesets returned by this
+** function. If an existing row with one or more NULL values stored in
+** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
+** only an INSERT is appears in the changeset. Similarly, if an existing row
+** with non-NULL PRIMARY KEY values is updated so that one or more of its
+** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
+** DELETE change only.
+**
+** The contents of a changeset may be traversed using an iterator created
+** using the [sqlite3changeset_start()] API. A changeset may be applied to
+** a database with a compatible schema using the [sqlite3changeset_apply()]
+** API.
+**
+** Following a successful call to this function, it is the responsibility of
+** the caller to eventually free the buffer that *ppChangeset points to using
+** [sqlite3_free()].
+**
+** <h3>Changeset Generation</h3>
+**
+** Once a table has been attached to a session object, the session object
+** records the primary key values of all new rows inserted into the table.
+** It also records the original primary key and other column values of any
+** deleted or updated rows. For each unique primary key value, data is only
+** recorded once - the first time a row with said primary key is inserted,
+** updated or deleted in the lifetime of the session.
+**
+** There is one exception to the previous paragraph: when a row is inserted,
+** updated or deleted, if one or more of its primary key columns contain a
+** NULL value, no record of the change is made.
+**
+** The session object therefore accumulates two types of records - those
+** that consist of primary key values only (created when the user inserts
+** a new record) and those that consist of the primary key values and the
+** original values of other table columns (created when the users deletes
+** or updates a record).
+**
+** When this function is called, the requested changeset is created using
+** both the accumulated records and the current contents of the database
+** file. Specifically:
+**
+** <ul>
+**   <li> For each record generated by an insert, the database is queried
+**        for a row with a matching primary key. If one is found, an INSERT
+**        change is added to the changeset. If no such row is found, no change 
+**        is added to the changeset.
+**
+**   <li> For each record generated by an update or delete, the database is 
+**        queried for a row with a matching primary key. If such a row is
+**        found and one or more of the non-primary key fields have been
+**        modified from their original values, an UPDATE change is added to 
+**        the changeset. Or, if no such row is found in the table, a DELETE 
+**        change is added to the changeset. If there is a row with a matching
+**        primary key in the database, but all fields contain their original
+**        values, no change is added to the changeset.
+** </ul>
+**
+** This means, amongst other things, that if a row is inserted and then later
+** deleted while a session object is active, neither the insert nor the delete
+** will be present in the changeset. Or if a row is deleted and then later a 
+** row with the same primary key values inserted while a session object is
+** active, the resulting changeset will contain an UPDATE change instead of
+** a DELETE and an INSERT.
+**
+** When a session object is disabled (see the [sqlite3session_enable()] API),
+** it does not accumulate records when rows are inserted, updated or deleted.
+** This may appear to have some counter-intuitive effects if a single row
+** is written to more than once during a session. For example, if a row
+** is inserted while a session object is enabled, then later deleted while 
+** the same session object is disabled, no INSERT record will appear in the
+** changeset, even though the delete took place while the session was disabled.
+** Or, if one field of a row is updated while a session is disabled, and 
+** another field of the same row is updated while the session is enabled, the
+** resulting changeset will contain an UPDATE change that updates both fields.
+*/
+int sqlite3session_changeset(
+  sqlite3_session *pSession,      /* Session object */
+  int *pnChangeset,               /* OUT: Size of buffer at *ppChangeset */
+  void **ppChangeset              /* OUT: Buffer containing changeset */
+);
+
+/*
+** CAPI3REF: Test if a changeset has recorded any changes.
+**
+** Return non-zero if no changes to attached tables have been recorded by 
+** the session object passed as the first argument. Otherwise, if one or 
+** more changes have been recorded, return zero.
+**
+** Even if this function returns zero, it is possible that calling
+** [sqlite3session_changeset()] on the session handle may still return a
+** changeset that contains no changes. This can happen when a row in 
+** an attached table is modified and then later on the original values 
+** are restored. However, if this function returns non-zero, then it is
+** guaranteed that a call to sqlite3session_changeset() will return a 
+** changeset containing zero changes.
+*/
+int sqlite3session_isempty(sqlite3_session *pSession);
+
+/*
+** CAPI3REF: Create An Iterator To Traverse A Changeset 
+**
+** Create an iterator used to iterate through the contents of a changeset.
+** If successful, *pp is set to point to the iterator handle and SQLITE_OK
+** is returned. Otherwise, if an error occurs, *pp is set to zero and an
+** SQLite error code is returned.
+**
+** The following functions can be used to advance and query a changeset 
+** iterator created by this function:
+**
+** <ul>
+**   <li> [sqlite3changeset_next()]
+**   <li> [sqlite3changeset_op()]
+**   <li> [sqlite3changeset_new()]
+**   <li> [sqlite3changeset_old()]
+** </ul>
+**
+** It is the responsibility of the caller to eventually destroy the iterator
+** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
+** changeset (pChangeset) must remain valid until after the iterator is
+** destroyed.
+**
+** Assuming the changeset blob was created by one of the
+** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
+** [sqlite3changeset_invert()] functions, all changes within the changeset 
+** that apply to a single table are grouped together. This means that when 
+** an application iterates through a changeset using an iterator created by 
+** this function, all changes that relate to a single table are visted 
+** consecutively. There is no chance that the iterator will visit a change 
+** the applies to table X, then one for table Y, and then later on visit 
+** another change for table X.
+*/
+int sqlite3changeset_start(
+  sqlite3_changeset_iter **pp,    /* OUT: New changeset iterator handle */
+  int nChangeset,                 /* Size of changeset blob in bytes */
+  void *pChangeset                /* Pointer to blob containing changeset */
+);
+
+/*
+** CAPI3REF: Advance A Changeset Iterator
+**
+** This function may only be used with iterators created by function
+** [sqlite3changeset_start()]. If it is called on an iterator passed to
+** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
+** is returned and the call has no effect.
+**
+** Immediately after an iterator is created by sqlite3changeset_start(), it
+** does not point to any change in the changeset. Assuming the changeset
+** is not empty, the first call to this function advances the iterator to
+** point to the first change in the changeset. Each subsequent call advances
+** the iterator to point to the next change in the changeset (if any). If
+** no error occurs and the iterator points to a valid change after a call
+** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 
+** Otherwise, if all changes in the changeset have already been visited,
+** SQLITE_DONE is returned.
+**
+** If an error occurs, an SQLite error code is returned. Possible error 
+** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 
+** SQLITE_NOMEM.
+*/
+int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
+** is not the case, this function returns [SQLITE_MISUSE].
+**
+** If argument pzTab is not NULL, then *pzTab is set to point to a
+** nul-terminated utf-8 encoded string containing the name of the table
+** affected by the current change. The buffer remains valid until either
+** sqlite3changeset_next() is called on the iterator or until the 
+** conflict-handler function returns. If pnCol is not NULL, then *pnCol is 
+** set to the number of columns in the table affected by the change. If
+** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
+** is an indirect change, or false (0) otherwise. See the documentation for
+** [sqlite3session_indirect()] for a description of direct and indirect
+** changes. Finally, if pOp is not NULL, then *pOp is set to one of 
+** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the 
+** type of change that the iterator currently points to.
+**
+** If no error occurs, SQLITE_OK is returned. If an error does occur, an
+** SQLite error code is returned. The values of the output variables may not
+** be trusted in this case.
+*/
+int sqlite3changeset_op(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  const char **pzTab,             /* OUT: Pointer to table name */
+  int *pnCol,                     /* OUT: Number of columns in table */
+  int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
+  int *pbIndirect                 /* OUT: True for an 'indirect' change */
+);
+
+/*
+** CAPI3REF: Obtain The Primary Key Definition Of A Table
+**
+** For each modified table, a changeset includes the following:
+**
+** <ul>
+**   <li> The number of columns in the table, and
+**   <li> Which of those columns make up the tables PRIMARY KEY.
+** </ul>
+**
+** This function is used to find which columns comprise the PRIMARY KEY of
+** the table modified by the change that iterator pIter currently points to.
+** If successful, *pabPK is set to point to an array of nCol entries, where
+** nCol is the number of columns in the table. Elements of *pabPK are set to
+** 0x01 if the corresponding column is part of the tables primary key, or
+** 0x00 if it is not.
+**
+** If argumet pnCol is not NULL, then *pnCol is set to the number of columns
+** in the table.
+**
+** If this function is called when the iterator does not point to a valid
+** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
+** SQLITE_OK is returned and the output variables populated as described
+** above.
+*/
+int sqlite3changeset_pk(
+  sqlite3_changeset_iter *pIter,  /* Iterator object */
+  unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
+  int *pnCol                      /* OUT: Number of entries in output array */
+);
+
+/*
+** CAPI3REF: Obtain old.* Values From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 
+** Furthermore, it may only be called if the type of change that the iterator
+** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
+** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the vector of 
+** original row values stored as part of the UPDATE or DELETE change and
+** returns SQLITE_OK. The name of the function comes from the fact that this 
+** is similar to the "old.*" columns available to update or delete triggers.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+int sqlite3changeset_old(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: Old value (or NULL pointer) */
+);
+
+/*
+** CAPI3REF: Obtain new.* Values From A Changeset Iterator
+**
+** The pIter argument passed to this function may either be an iterator
+** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
+** created by [sqlite3changeset_start()]. In the latter case, the most recent
+** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 
+** Furthermore, it may only be called if the type of change that the iterator
+** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
+** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the vector of 
+** new row values stored as part of the UPDATE or INSERT change and
+** returns SQLITE_OK. If the change is an UPDATE and does not include
+** a new value for the requested column, *ppValue is set to NULL and 
+** SQLITE_OK returned. The name of the function comes from the fact that 
+** this is similar to the "new.*" columns available to update or delete 
+** triggers.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+int sqlite3changeset_new(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: New value (or NULL pointer) */
+);
+
+/*
+** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
+**
+** This function should only be used with iterator objects passed to a
+** conflict-handler callback by [sqlite3changeset_apply()] with either
+** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
+** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
+** is set to NULL.
+**
+** Argument iVal must be greater than or equal to 0, and less than the number
+** of columns in the table affected by the current change. Otherwise,
+** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
+**
+** If successful, this function sets *ppValue to point to a protected
+** sqlite3_value object containing the iVal'th value from the 
+** "conflicting row" associated with the current conflict-handler callback
+** and returns SQLITE_OK.
+**
+** If some other error occurs (e.g. an OOM condition), an SQLite error code
+** is returned and *ppValue is set to NULL.
+*/
+int sqlite3changeset_conflict(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int iVal,                       /* Column number */
+  sqlite3_value **ppValue         /* OUT: Value from conflicting row */
+);
+
+/*
+** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
+**
+** This function may only be called with an iterator passed to an
+** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
+** it sets the output variable to the total number of known foreign key
+** violations in the destination database and returns SQLITE_OK.
+**
+** In all other cases this function returns SQLITE_MISUSE.
+*/
+int sqlite3changeset_fk_conflicts(
+  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
+  int *pnOut                      /* OUT: Number of FK violations */
+);
+
+
+/*
+** CAPI3REF: Finalize A Changeset Iterator
+**
+** This function is used to finalize an iterator allocated with
+** [sqlite3changeset_start()].
+**
+** This function should only be called on iterators created using the
+** [sqlite3changeset_start()] function. If an application calls this
+** function with an iterator passed to a conflict-handler by
+** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
+** call has no effect.
+**
+** If an error was encountered within a call to an sqlite3changeset_xxx()
+** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 
+** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
+** to that error is returned by this function. Otherwise, SQLITE_OK is
+** returned. This is to allow the following pattern (pseudo-code):
+**
+**   sqlite3changeset_start();
+**   while( SQLITE_ROW==sqlite3changeset_next() ){
+**     // Do something with change.
+**   }
+**   rc = sqlite3changeset_finalize();
+**   if( rc!=SQLITE_OK ){
+**     // An error has occurred 
+**   }
+*/
+int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
+
+/*
+** CAPI3REF: Invert A Changeset
+**
+** This function is used to "invert" a changeset object. Applying an inverted
+** changeset to a database reverses the effects of applying the uninverted
+** changeset. Specifically:
+**
+** <ul>
+**   <li> Each DELETE change is changed to an INSERT, and
+**   <li> Each INSERT change is changed to a DELETE, and
+**   <li> For each UPDATE change, the old.* and new.* values are exchanged.
+** </ul>
+**
+** If successful, a pointer to a buffer containing the inverted changeset
+** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
+** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
+** zeroed and an SQLite error code returned.
+**
+** It is the responsibility of the caller to eventually call sqlite3_free()
+** on the *ppOut pointer to free the buffer allocation following a successful 
+** call to this function.
+**
+** WARNING/TODO: This function currently assumes that the input is a valid
+** changeset. If it is not, the results are undefined.
+*/
+int sqlite3changeset_invert(
+  int nIn, const void *pIn,       /* Input changeset */
+  int *pnOut, void **ppOut        /* OUT: Inverse of input */
+);
+
+/*
+** CAPI3REF: Concatenate Two Changeset Objects
+**
+** This function is used to concatenate two changesets, A and B, into a 
+** single changeset. The result is a changeset equivalent to applying
+** changeset A followed by changeset B. 
+**
+** Rows are identified by the values in their PRIMARY KEY columns. A change
+** in changeset A is considered to apply to the same row as a change in
+** changeset B if the two rows have the same primary key.
+**
+** Changes to rows that appear only in changeset A or B are copied into the
+** output changeset. Or, if both changeset A and B contain a change that
+** applies to a single row, the output depends on the type of each change,
+** as follows:
+**
+** <table border=1 style="margin-left:8ex;margin-right:8ex">
+**   <tr><th style="white-space:pre">Change A      </th>
+**       <th style="white-space:pre">Change B      </th>
+**       <th>Output Change
+**   <tr><td>INSERT <td>INSERT <td>
+**       Change A is copied into the output changeset. Change B is discarded.
+**       This case does not occur if changeset B is recorded immediately after
+**       changeset A. 
+**   <tr><td>INSERT <td>UPDATE <td>
+**       An INSERT change is copied into the output changeset. The values in
+**       the INSERT change are as if the row was inserted by change A and then
+**       updated according to change B.
+**   <tr><td>INSERT <td>DELETE <td>
+**       No change at all is copied into the output changeset.
+**   <tr><td>UPDATE <td>INSERT <td>
+**       Change A is copied into the output changeset. Change B is discarded.
+**       This case does not occur if changeset B is recorded immediately after
+**       changeset A. 
+**   <tr><td>UPDATE <td>UPDATE <td>
+**       A single UPDATE is copied into the output changeset. The accompanying
+**       values are as if the row was updated once by change A and then again
+**       by change B.
+**   <tr><td>UPDATE <td>DELETE <td>
+**       A single DELETE is copied into the output changeset.
+**   <tr><td>DELETE <td>INSERT <td>
+**       If one or more of the column values in the row inserted by change 
+**       B differ from those in the row deleted by change A, an UPDATE
+**       change is added to the output changeset. Otherwise, if the inserted
+**       row is exactly the same as the deleted row, no change is added to
+**       the output changeset.
+**   <tr><td>DELETE <td>UPDATE <td>
+**       Change A is copied into the output changeset. Change B is discarded.
+**       This case does not occur if changeset B is recorded immediately after
+**       changeset A. 
+**   <tr><td>DELETE <td>DELETE <td>
+**       Change A is copied into the output changeset. Change B is discarded.
+**       This case does not occur if changeset B is recorded immediately after
+**       changeset A. 
+** </table>
+**
+** If the two changesets contain changes to the same table, then the number
+** of columns and the position of the primary key columns for the table must
+** be the same in each changeset. If this is not the case, attempting to
+** concatenate the two changesets together fails and this function returns
+** SQLITE_SCHEMA. If either of the two input changesets appear to be corrupt,
+** and the corruption is detected, SQLITE_CORRUPT is returned. Or, if an
+** out-of-memory condition occurs during processing, this function returns
+** SQLITE_NOMEM.
+**
+** If none of the above errors occur, SQLITE_OK is returned and *ppOut set
+** to point to a buffer containing the output changeset. It is the 
+** responsibility of the caller to eventually call sqlite3_free() on *ppOut 
+** to release memory allocated for the buffer. *pnOut is set to the number 
+** of bytes in the output changeset. If an error does occur, both *ppOut and 
+** *pnOut are set to zero before returning.
+*/
+int sqlite3changeset_concat(
+  int nA,                         /* Number of bytes in buffer pA */
+  void *pA,                       /* Pointer to buffer containing changeset A */
+  int nB,                         /* Number of bytes in buffer pB */
+  void *pB,                       /* Pointer to buffer containing changeset B */
+  int *pnOut,                     /* OUT: Number of bytes in output changeset */
+  void **ppOut                    /* OUT: Buffer containing output changeset */
+);
+
+/*
+** CAPI3REF: Apply A Changeset To A Database
+**
+** Apply a changeset to a database. This function attempts to update the
+** "main" database attached to handle db with the changes found in the
+** changeset passed via the second and third arguments.
+**
+** The fourth argument (xFilter) passed to this function is the "filter
+** callback". If it is not NULL, then for each table affected by at least one
+** change in the changeset, the filter callback is invoked with
+** the table name as the second argument, and a copy of the context pointer
+** passed as the sixth argument to this function as the first. If the "filter
+** callback" returns zero, then no attempt is made to apply any changes to 
+** the table. Otherwise, if the return value is non-zero or the xFilter
+** argument to this function is NULL, all changes related to the table are
+** attempted.
+**
+** For each table that is not excluded by the filter callback, this function 
+** tests that the target database contains a compatible table. A table is 
+** considered compatible if all of the following are true:
+**
+** <ul>
+**   <li> The table has the same name as the name recorded in the 
+**        changeset, and
+**   <li> The table has the same number of columns as recorded in the 
+**        changeset, and
+**   <li> The table has primary key columns in the same position as 
+**        recorded in the changeset.
+** </ul>
+**
+** If there is no compatible table, it is not an error, but none of the
+** changes associated with the table are applied. A warning message is issued
+** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
+** one such warning is issued for each table in the changeset.
+**
+** For each change for which there is a compatible table, an attempt is made 
+** to modify the table contents according to the UPDATE, INSERT or DELETE 
+** change. If a change cannot be applied cleanly, the conflict handler 
+** function passed as the fifth argument to sqlite3changeset_apply() may be 
+** invoked. A description of exactly when the conflict handler is invoked for 
+** each type of change is below.
+**
+** Each time the conflict handler function is invoked, it must return one
+** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 
+** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
+** if the second argument passed to the conflict handler is either
+** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
+** returns an illegal value, any changes already made are rolled back and
+** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 
+** actions are taken by sqlite3changeset_apply() depending on the value
+** returned by each invocation of the conflict-handler function. Refer to
+** the documentation for the three 
+** [SQLITE_CHANGESET_OMIT|available return values] for details.
+**
+** <dl>
+** <dt>DELETE Changes<dd>
+**   For each DELETE change, this function checks if the target database 
+**   contains a row with the same primary key value (or values) as the 
+**   original row values stored in the changeset. If it does, and the values 
+**   stored in all non-primary key columns also match the values stored in 
+**   the changeset the row is deleted from the target database.
+**
+**   If a row with matching primary key values is found, but one or more of
+**   the non-primary key fields contains a value different from the original
+**   row value stored in the changeset, the conflict-handler function is
+**   invoked with [SQLITE_CHANGESET_DATA] as the second argument.
+**
+**   If no row with matching primary key values is found in the database,
+**   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
+**   passed as the second argument.
+**
+**   If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
+**   (which can only happen if a foreign key constraint is violated), the
+**   conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
+**   passed as the second argument. This includes the case where the DELETE
+**   operation is attempted because an earlier call to the conflict handler
+**   function returned [SQLITE_CHANGESET_REPLACE].
+**
+** <dt>INSERT Changes<dd>
+**   For each INSERT change, an attempt is made to insert the new row into
+**   the database.
+**
+**   If the attempt to insert the row fails because the database already 
+**   contains a row with the same primary key values, the conflict handler
+**   function is invoked with the second argument set to 
+**   [SQLITE_CHANGESET_CONFLICT].
+**
+**   If the attempt to insert the row fails because of some other constraint
+**   violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 
+**   invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
+**   This includes the case where the INSERT operation is re-attempted because 
+**   an earlier call to the conflict handler function returned 
+**   [SQLITE_CHANGESET_REPLACE].
+**
+** <dt>UPDATE Changes<dd>
+**   For each UPDATE change, this function checks if the target database 
+**   contains a row with the same primary key value (or values) as the 
+**   original row values stored in the changeset. If it does, and the values 
+**   stored in all non-primary key columns also match the values stored in 
+**   the changeset the row is updated within the target database.
+**
+**   If a row with matching primary key values is found, but one or more of
+**   the non-primary key fields contains a value different from an original
+**   row value stored in the changeset, the conflict-handler function is
+**   invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
+**   UPDATE changes only contain values for non-primary key fields that are
+**   to be modified, only those fields need to match the original values to
+**   avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
+**
+**   If no row with matching primary key values is found in the database,
+**   the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
+**   passed as the second argument.
+**
+**   If the UPDATE operation is attempted, but SQLite returns 
+**   SQLITE_CONSTRAINT, the conflict-handler function is invoked with 
+**   [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
+**   This includes the case where the UPDATE operation is attempted after 
+**   an earlier call to the conflict handler function returned
+**   [SQLITE_CHANGESET_REPLACE].  
+** </dl>
+**
+** It is safe to execute SQL statements, including those that write to the
+** table that the callback related to, from within the xConflict callback.
+** This can be used to further customize the applications conflict
+** resolution strategy.
+**
+** All changes made by this function are enclosed in a savepoint transaction.
+** If any other error (aside from a constraint failure when attempting to
+** write to the target database) occurs, then the savepoint transaction is
+** rolled back, restoring the target database to its original state, and an 
+** SQLite error code returned.
+*/
+int sqlite3changeset_apply(
+  sqlite3 *db,                    /* Apply change to "main" db of this handle */
+  int nChangeset,                 /* Size of changeset in bytes */
+  void *pChangeset,               /* Changeset blob */
+  int(*xFilter)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    const char *zTab              /* Table name */
+  ),
+  int(*xConflict)(
+    void *pCtx,                   /* Copy of sixth arg to _apply() */
+    int eConflict,                /* DATA, MISSING, CONFLICT, CONSTRAINT */
+    sqlite3_changeset_iter *p     /* Handle describing change and conflict */
+  ),
+  void *pCtx                      /* First argument passed to xConflict */
+);
+
+/* 
+** CAPI3REF: Constants Passed To The Conflict Handler
+**
+** Values that may be passed as the second argument to a conflict-handler.
+**
+** <dl>
+** <dt>SQLITE_CHANGESET_DATA<dd>
+**   The conflict handler is invoked with CHANGESET_DATA as the second argument
+**   when processing a DELETE or UPDATE change if a row with the required
+**   PRIMARY KEY fields is present in the database, but one or more other 
+**   (non primary-key) fields modified by the update do not contain the 
+**   expected "before" values.
+** 
+**   The conflicting row, in this case, is the database row with the matching
+**   primary key.
+** 
+** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
+**   The conflict handler is invoked with CHANGESET_NOTFOUND as the second
+**   argument when processing a DELETE or UPDATE change if a row with the
+**   required PRIMARY KEY fields is not present in the database.
+** 
+**   There is no conflicting row in this case. The results of invoking the
+**   sqlite3changeset_conflict() API are undefined.
+** 
+** <dt>SQLITE_CHANGESET_CONFLICT<dd>
+**   CHANGESET_CONFLICT is passed as the second argument to the conflict
+**   handler while processing an INSERT change if the operation would result 
+**   in duplicate primary key values.
+** 
+**   The conflicting row in this case is the database row with the matching
+**   primary key.
+**
+** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
+**   If foreign key handling is enabled, and applying a changeset leaves the
+**   database in a state containing foreign key violations, the conflict 
+**   handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
+**   exactly once before the changeset is committed. If the conflict handler
+**   returns CHANGESET_OMIT, the changes, including those that caused the
+**   foreign key constraint violation, are committed. Or, if it returns
+**   CHANGESET_ABORT, the changeset is rolled back.
+**
+**   No current or conflicting row information is provided. The only function
+**   it is possible to call on the supplied sqlite3_changeset_iter handle
+**   is sqlite3changeset_fk_conflicts().
+** 
+** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
+**   If any other constraint violation occurs while applying a change (i.e. 
+**   a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 
+**   invoked with CHANGESET_CONSTRAINT as the second argument.
+** 
+**   There is no conflicting row in this case. The results of invoking the
+**   sqlite3changeset_conflict() API are undefined.
+**
+** </dl>
+*/
+#define SQLITE_CHANGESET_DATA        1
+#define SQLITE_CHANGESET_NOTFOUND    2
+#define SQLITE_CHANGESET_CONFLICT    3
+#define SQLITE_CHANGESET_CONSTRAINT  4
+#define SQLITE_CHANGESET_FOREIGN_KEY 5
+
+/* 
+** CAPI3REF: Constants Returned By The Conflict Handler
+**
+** A conflict handler callback must return one of the following three values.
+**
+** <dl>
+** <dt>SQLITE_CHANGESET_OMIT<dd>
+**   If a conflict handler returns this value no special action is taken. The
+**   change that caused the conflict is not applied. The session module 
+**   continues to the next change in the changeset.
+**
+** <dt>SQLITE_CHANGESET_REPLACE<dd>
+**   This value may only be returned if the second argument to the conflict
+**   handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
+**   is not the case, any changes applied so far are rolled back and the 
+**   call to sqlite3changeset_apply() returns SQLITE_MISUSE.
+**
+**   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
+**   handler, then the conflicting row is either updated or deleted, depending
+**   on the type of change.
+**
+**   If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
+**   handler, then the conflicting row is removed from the database and a
+**   second attempt to apply the change is made. If this second attempt fails,
+**   the original row is restored to the database before continuing.
+**
+** <dt>SQLITE_CHANGESET_ABORT<dd>
+**   If this value is returned, any changes applied so far are rolled back 
+**   and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
+** </dl>
+*/
+#define SQLITE_CHANGESET_OMIT       0
+#define SQLITE_CHANGESET_REPLACE    1
+#define SQLITE_CHANGESET_ABORT      2
+
+/*
+** Make sure we can call this stuff from C++.
+*/
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* SQLITE_ENABLE_SESSION && SQLITE_ENABLE_PREUPDATE_HOOK */

ext/session/test_session.c

@@ -0,0 +1,674 @@
+
+#if defined(SQLITE_TEST) && defined(SQLITE_ENABLE_SESSION) \
+ && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+
+#include "sqlite3session.h"
+#include <assert.h>
+#include <string.h>
+#include <tcl.h>
+
+typedef struct TestSession TestSession;
+struct TestSession {
+  sqlite3_session *pSession;
+  Tcl_Interp *interp;
+  Tcl_Obj *pFilterScript;
+};
+
+static int test_session_error(Tcl_Interp *interp, int rc){
+  extern const char *sqlite3ErrName(int);
+  Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
+  return TCL_ERROR;
+}
+
+static int test_table_filter(void *pCtx, const char *zTbl){
+  TestSession *p = (TestSession*)pCtx;
+  Tcl_Obj *pEval;
+  int rc;
+  int bRes = 0;
+
+  pEval = Tcl_DuplicateObj(p->pFilterScript);
+  Tcl_IncrRefCount(pEval);
+  rc = Tcl_ListObjAppendElement(p->interp, pEval, Tcl_NewStringObj(zTbl, -1));
+  if( rc==TCL_OK ){
+    rc = Tcl_EvalObjEx(p->interp, pEval, TCL_EVAL_GLOBAL);
+  }
+  if( rc==TCL_OK ){
+    rc = Tcl_GetBooleanFromObj(p->interp, Tcl_GetObjResult(p->interp), &bRes);
+  }
+  if( rc!=TCL_OK ){
+    /* printf("error: %s\n", Tcl_GetStringResult(p->interp)); */
+    Tcl_BackgroundError(p->interp);
+  }
+  Tcl_DecrRefCount(pEval);
+
+  return bRes;
+}
+
+/*
+** Tclcmd:  $session attach TABLE
+**          $session changeset
+**          $session delete
+**          $session enable BOOL
+**          $session indirect INTEGER
+**          $session table_filter SCRIPT
+*/
+static int test_session_cmd(
+  void *clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  TestSession *p = (TestSession*)clientData;
+  sqlite3_session *pSession = p->pSession;
+  struct SessionSubcmd {
+    const char *zSub;
+    int nArg;
+    const char *zMsg;
+    int iSub;
+  } aSub[] = {
+    { "attach",       1, "TABLE",  }, /* 0 */
+    { "changeset",    0, "",       }, /* 1 */
+    { "delete",       0, "",       }, /* 2 */
+    { "enable",       1, "BOOL",   }, /* 3 */
+    { "indirect",     1, "BOOL",   }, /* 4 */
+    { "isempty",      0, "",       }, /* 5 */
+    { "table_filter", 1, "SCRIPT", }, /* 6 */
+    { 0 }
+  };
+  int iSub;
+  int rc;
+
+  if( objc<2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");
+    return TCL_ERROR;
+  }
+  rc = Tcl_GetIndexFromObjStruct(interp, 
+      objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iSub
+  );
+  if( rc!=TCL_OK ) return rc;
+  if( objc!=2+aSub[iSub].nArg ){
+    Tcl_WrongNumArgs(interp, 2, objv, aSub[iSub].zMsg);
+    return TCL_ERROR;
+  }
+
+  switch( iSub ){
+    case 0: {      /* attach */
+      char *zArg = Tcl_GetString(objv[2]);
+      if( zArg[0]=='*' && zArg[1]=='\0' ) zArg = 0;
+      rc = sqlite3session_attach(pSession, zArg);
+      if( rc!=SQLITE_OK ){
+        return test_session_error(interp, rc);
+      }
+      break;
+    }
+
+    case 1: {      /* changeset */
+      int nChange;
+      void *pChange;
+      rc = sqlite3session_changeset(pSession, &nChange, &pChange);
+      if( rc==SQLITE_OK ){
+        Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(pChange, nChange)); 
+        sqlite3_free(pChange);
+      }else{
+        return test_session_error(interp, rc);
+      }
+      break;
+    }
+
+    case 2:        /* delete */
+      Tcl_DeleteCommand(interp, Tcl_GetString(objv[0]));
+      break;
+
+    case 3: {      /* enable */
+      int val;
+      if( Tcl_GetIntFromObj(interp, objv[2], &val) ) return TCL_ERROR;
+      val = sqlite3session_enable(pSession, val);
+      Tcl_SetObjResult(interp, Tcl_NewBooleanObj(val));
+      break;
+    }
+
+    case 4: {      /* indirect */
+      int val;
+      if( Tcl_GetIntFromObj(interp, objv[2], &val) ) return TCL_ERROR;
+      val = sqlite3session_indirect(pSession, val);
+      Tcl_SetObjResult(interp, Tcl_NewBooleanObj(val));
+      break;
+    }
+
+    case 5: {      /* isempty */
+      int val;
+      val = sqlite3session_isempty(pSession);
+      Tcl_SetObjResult(interp, Tcl_NewBooleanObj(val));
+      break;
+    }
+            
+    case 6: {      /* table_filter */
+      if( p->pFilterScript ) Tcl_DecrRefCount(p->pFilterScript);
+      p->interp = interp;
+      p->pFilterScript = Tcl_DuplicateObj(objv[2]);
+      Tcl_IncrRefCount(p->pFilterScript);
+      sqlite3session_table_filter(pSession, test_table_filter, clientData);
+      break;
+    }
+  }
+
+  return TCL_OK;
+}
+
+static void test_session_del(void *clientData){
+  TestSession *p = (TestSession*)clientData;
+  if( p->pFilterScript ) Tcl_DecrRefCount(p->pFilterScript);
+  sqlite3session_delete(p->pSession);
+  ckfree((char*)p);
+}
+
+/*
+** Tclcmd:  sqlite3session CMD DB-HANDLE DB-NAME
+*/
+static int test_sqlite3session(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  Tcl_CmdInfo info;
+  int rc;                         /* sqlite3session_create() return code */
+  TestSession *p;                 /* New wrapper object */
+
+  if( objc!=4 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CMD DB-HANDLE DB-NAME");
+    return TCL_ERROR;
+  }
+
+  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(objv[2]), &info) ){
+    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(objv[2]), 0);
+    return TCL_ERROR;
+  }
+  db = *(sqlite3 **)info.objClientData;
+
+  p = (TestSession*)ckalloc(sizeof(TestSession));
+  memset(p, 0, sizeof(TestSession));
+  rc = sqlite3session_create(db, Tcl_GetString(objv[3]), &p->pSession);
+  if( rc!=SQLITE_OK ){
+    ckfree((char*)p);
+    return test_session_error(interp, rc);
+  }
+
+  Tcl_CreateObjCommand(
+      interp, Tcl_GetString(objv[1]), test_session_cmd, (ClientData)p,
+      test_session_del
+  );
+  Tcl_SetObjResult(interp, objv[1]);
+  return TCL_OK;
+}
+
+static void test_append_value(Tcl_Obj *pList, sqlite3_value *pVal){
+  if( pVal==0 ){
+    Tcl_ListObjAppendElement(0, pList, Tcl_NewObj());
+    Tcl_ListObjAppendElement(0, pList, Tcl_NewObj());
+  }else{
+    Tcl_Obj *pObj;
+    switch( sqlite3_value_type(pVal) ){
+      case SQLITE_NULL:
+        Tcl_ListObjAppendElement(0, pList, Tcl_NewStringObj("n", 1));
+        pObj = Tcl_NewObj();
+        break;
+      case SQLITE_INTEGER:
+        Tcl_ListObjAppendElement(0, pList, Tcl_NewStringObj("i", 1));
+        pObj = Tcl_NewWideIntObj(sqlite3_value_int64(pVal));
+        break;
+      case SQLITE_FLOAT:
+        Tcl_ListObjAppendElement(0, pList, Tcl_NewStringObj("f", 1));
+        pObj = Tcl_NewDoubleObj(sqlite3_value_double(pVal));
+        break;
+      case SQLITE_TEXT: {
+        const char *z = (char*)sqlite3_value_blob(pVal);
+        int n = sqlite3_value_bytes(pVal);
+        Tcl_ListObjAppendElement(0, pList, Tcl_NewStringObj("t", 1));
+        pObj = Tcl_NewStringObj(z, n);
+        break;
+      }
+      case SQLITE_BLOB:
+        Tcl_ListObjAppendElement(0, pList, Tcl_NewStringObj("b", 1));
+        pObj = Tcl_NewByteArrayObj(
+            sqlite3_value_blob(pVal),
+            sqlite3_value_bytes(pVal)
+        );
+        break;
+    }
+    Tcl_ListObjAppendElement(0, pList, pObj);
+  }
+}
+
+typedef struct TestConflictHandler TestConflictHandler;
+struct TestConflictHandler {
+  Tcl_Interp *interp;
+  Tcl_Obj *pConflictScript;
+  Tcl_Obj *pFilterScript;
+};
+
+static int test_obj_eq_string(Tcl_Obj *p, const char *z){
+  int n;
+  int nObj;
+  char *zObj;
+
+  n = (int)strlen(z);
+  zObj = Tcl_GetStringFromObj(p, &nObj);
+
+  return (nObj==n && (n==0 || 0==memcmp(zObj, z, n)));
+}
+
+static int test_filter_handler(
+  void *pCtx,                     /* Pointer to TestConflictHandler structure */
+  const char *zTab                /* Table name */
+){
+  TestConflictHandler *p = (TestConflictHandler *)pCtx;
+  int res = 1;
+  Tcl_Obj *pEval;
+  Tcl_Interp *interp = p->interp;
+
+  pEval = Tcl_DuplicateObj(p->pFilterScript);
+  Tcl_IncrRefCount(pEval);
+
+  if( TCL_OK!=Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj(zTab, -1))
+   || TCL_OK!=Tcl_EvalObjEx(interp, pEval, TCL_EVAL_GLOBAL) 
+   || TCL_OK!=Tcl_GetIntFromObj(interp, Tcl_GetObjResult(interp), &res)
+  ){
+    Tcl_BackgroundError(interp);
+  }
+
+  Tcl_DecrRefCount(pEval);
+  return res;
+}  
+
+static int test_conflict_handler(
+  void *pCtx,                     /* Pointer to TestConflictHandler structure */
+  int eConf,                      /* DATA, MISSING, CONFLICT, CONSTRAINT */
+  sqlite3_changeset_iter *pIter   /* Handle describing change and conflict */
+){
+  TestConflictHandler *p = (TestConflictHandler *)pCtx;
+  Tcl_Obj *pEval;
+  Tcl_Interp *interp = p->interp;
+  int ret = 0;                    /* Return value */
+
+  int op;                         /* SQLITE_UPDATE, DELETE or INSERT */
+  const char *zTab;               /* Name of table conflict is on */
+  int nCol;                       /* Number of columns in table zTab */
+
+  pEval = Tcl_DuplicateObj(p->pConflictScript);
+  Tcl_IncrRefCount(pEval);
+
+  sqlite3changeset_op(pIter, &zTab, &nCol, &op, 0);
+
+  if( eConf==SQLITE_CHANGESET_FOREIGN_KEY ){
+    int nFk;
+    sqlite3changeset_fk_conflicts(pIter, &nFk);
+    Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj("FOREIGN_KEY", -1));
+    Tcl_ListObjAppendElement(0, pEval, Tcl_NewIntObj(nFk));
+  }else{
+
+    /* Append the operation type. */
+    Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj(
+        op==SQLITE_INSERT ? "INSERT" :
+        op==SQLITE_UPDATE ? "UPDATE" : 
+        "DELETE", -1
+    ));
+  
+    /* Append the table name. */
+    Tcl_ListObjAppendElement(0, pEval, Tcl_NewStringObj(zTab, -1));
+  
+    /* Append the conflict type. */
+    switch( eConf ){
+      case SQLITE_CHANGESET_DATA:
+        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("DATA",-1));
+        break;
+      case SQLITE_CHANGESET_NOTFOUND:
+        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("NOTFOUND",-1));
+        break;
+      case SQLITE_CHANGESET_CONFLICT:
+        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("CONFLICT",-1));
+        break;
+      case SQLITE_CHANGESET_CONSTRAINT:
+        Tcl_ListObjAppendElement(interp, pEval,Tcl_NewStringObj("CONSTRAINT",-1));
+        break;
+    }
+  
+    /* If this is not an INSERT, append the old row */
+    if( op!=SQLITE_INSERT ){
+      int i;
+      Tcl_Obj *pOld = Tcl_NewObj();
+      for(i=0; i<nCol; i++){
+        sqlite3_value *pVal;
+        sqlite3changeset_old(pIter, i, &pVal);
+        test_append_value(pOld, pVal);
+      }
+      Tcl_ListObjAppendElement(0, pEval, pOld);
+    }
+
+    /* If this is not a DELETE, append the new row */
+    if( op!=SQLITE_DELETE ){
+      int i;
+      Tcl_Obj *pNew = Tcl_NewObj();
+      for(i=0; i<nCol; i++){
+        sqlite3_value *pVal;
+        sqlite3changeset_new(pIter, i, &pVal);
+        test_append_value(pNew, pVal);
+      }
+      Tcl_ListObjAppendElement(0, pEval, pNew);
+    }
+
+    /* If this is a CHANGESET_DATA or CHANGESET_CONFLICT conflict, append
+     ** the conflicting row.  */
+    if( eConf==SQLITE_CHANGESET_DATA || eConf==SQLITE_CHANGESET_CONFLICT ){
+      int i;
+      Tcl_Obj *pConflict = Tcl_NewObj();
+      for(i=0; i<nCol; i++){
+        int rc;
+        sqlite3_value *pVal;
+        rc = sqlite3changeset_conflict(pIter, i, &pVal);
+        assert( rc==SQLITE_OK );
+        test_append_value(pConflict, pVal);
+      }
+      Tcl_ListObjAppendElement(0, pEval, pConflict);
+    }
+
+    /***********************************************************************
+     ** This block is purely for testing some error conditions.
+     */
+    if( eConf==SQLITE_CHANGESET_CONSTRAINT 
+     || eConf==SQLITE_CHANGESET_NOTFOUND 
+    ){
+      sqlite3_value *pVal;
+      int rc = sqlite3changeset_conflict(pIter, 0, &pVal);
+      assert( rc==SQLITE_MISUSE );
+    }else{
+      sqlite3_value *pVal;
+      int rc = sqlite3changeset_conflict(pIter, -1, &pVal);
+      assert( rc==SQLITE_RANGE );
+      rc = sqlite3changeset_conflict(pIter, nCol, &pVal);
+      assert( rc==SQLITE_RANGE );
+    }
+    if( op==SQLITE_DELETE ){
+      sqlite3_value *pVal;
+      int rc = sqlite3changeset_new(pIter, 0, &pVal);
+      assert( rc==SQLITE_MISUSE );
+    }else{
+      sqlite3_value *pVal;
+      int rc = sqlite3changeset_new(pIter, -1, &pVal);
+      assert( rc==SQLITE_RANGE );
+      rc = sqlite3changeset_new(pIter, nCol, &pVal);
+      assert( rc==SQLITE_RANGE );
+    }
+    if( op==SQLITE_INSERT ){
+      sqlite3_value *pVal;
+      int rc = sqlite3changeset_old(pIter, 0, &pVal);
+      assert( rc==SQLITE_MISUSE );
+    }else{
+      sqlite3_value *pVal;
+      int rc = sqlite3changeset_old(pIter, -1, &pVal);
+      assert( rc==SQLITE_RANGE );
+      rc = sqlite3changeset_old(pIter, nCol, &pVal);
+      assert( rc==SQLITE_RANGE );
+    }
+    /* End of testing block
+    ***********************************************************************/
+  }
+
+  if( TCL_OK!=Tcl_EvalObjEx(interp, pEval, TCL_EVAL_GLOBAL) ){
+    Tcl_BackgroundError(interp);
+  }else{
+    Tcl_Obj *pRes = Tcl_GetObjResult(interp);
+    if( test_obj_eq_string(pRes, "OMIT") || test_obj_eq_string(pRes, "") ){
+      ret = SQLITE_CHANGESET_OMIT;
+    }else if( test_obj_eq_string(pRes, "REPLACE") ){
+      ret = SQLITE_CHANGESET_REPLACE;
+    }else if( test_obj_eq_string(pRes, "ABORT") ){
+      ret = SQLITE_CHANGESET_ABORT;
+    }else{
+      Tcl_GetIntFromObj(0, pRes, &ret);
+    }
+  }
+
+  Tcl_DecrRefCount(pEval);
+  return ret;
+}
+
+/*
+** sqlite3changeset_apply DB CHANGESET CONFLICT-SCRIPT ?FILTER-SCRIPT?
+*/
+static int test_sqlite3changeset_apply(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;                    /* Database handle */
+  Tcl_CmdInfo info;               /* Database Tcl command (objv[1]) info */
+  int rc;                         /* Return code from changeset_invert() */
+  void *pChangeset;               /* Buffer containing changeset */
+  int nChangeset;                 /* Size of buffer aChangeset in bytes */
+  TestConflictHandler ctx;
+
+  if( objc!=4 && objc!=5 ){
+    Tcl_WrongNumArgs(interp, 1, objv, 
+        "DB CHANGESET CONFLICT-SCRIPT ?FILTER-SCRIPT?"
+    );
+    return TCL_ERROR;
+  }
+  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(objv[1]), &info) ){
+    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(objv[2]), 0);
+    return TCL_ERROR;
+  }
+  db = *(sqlite3 **)info.objClientData;
+  pChangeset = (void *)Tcl_GetByteArrayFromObj(objv[2], &nChangeset);
+  ctx.pConflictScript = objv[3];
+  ctx.pFilterScript = objc==5 ? objv[4] : 0;
+  ctx.interp = interp;
+
+  rc = sqlite3changeset_apply(db, nChangeset, pChangeset, 
+      (objc==5) ? test_filter_handler : 0, test_conflict_handler, (void *)&ctx
+  );
+  if( rc!=SQLITE_OK ){
+    return test_session_error(interp, rc);
+  }
+  Tcl_ResetResult(interp);
+  return TCL_OK;
+}
+
+/*
+** sqlite3changeset_invert CHANGESET
+*/
+static int test_sqlite3changeset_invert(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;                         /* Return code from changeset_invert() */
+  void *aChangeset;               /* Input changeset */
+  int nChangeSet;                 /* Size of buffer aChangeset in bytes */
+  void *aOut;                     /* Output changeset */
+  int nOut;                       /* Size of buffer aOut in bytes */
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CHANGESET");
+    return TCL_ERROR;
+  }
+  aChangeset = (void *)Tcl_GetByteArrayFromObj(objv[1], &nChangeSet);
+
+  rc = sqlite3changeset_invert(nChangeSet, aChangeset, &nOut, &aOut);
+  if( rc!=SQLITE_OK ){
+    return test_session_error(interp, rc);
+  }
+  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj((unsigned char *)aOut, nOut));
+  sqlite3_free(aOut);
+  return TCL_OK;
+}
+
+/*
+** sqlite3changeset_concat LEFT RIGHT
+*/
+static int test_sqlite3changeset_concat(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc;                         /* Return code from changeset_invert() */
+  void *aLeft;                    /* Input changeset */
+  int nLeft;                      /* Size of buffer aChangeset in bytes */
+  void *aRight;                   /* Input changeset */
+  int nRight;                     /* Size of buffer aChangeset in bytes */
+  void *aOut;                     /* Output changeset */
+  int nOut;                       /* Size of buffer aOut in bytes */
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "LEFT RIGHT");
+    return TCL_ERROR;
+  }
+  aLeft = (void *)Tcl_GetByteArrayFromObj(objv[1], &nLeft);
+  aRight = (void *)Tcl_GetByteArrayFromObj(objv[2], &nRight);
+
+  rc = sqlite3changeset_concat(nLeft, aLeft, nRight, aRight, &nOut, &aOut);
+  if( rc!=SQLITE_OK ){
+    return test_session_error(interp, rc);
+  }
+  Tcl_SetObjResult(interp, Tcl_NewByteArrayObj((unsigned char *)aOut, nOut));
+  sqlite3_free(aOut);
+  return TCL_OK;
+}
+
+/*
+** sqlite3session_foreach VARNAME CHANGESET SCRIPT
+*/
+static int test_sqlite3session_foreach(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  void *pChangeSet;
+  int nChangeSet;
+  sqlite3_changeset_iter *pIter;
+  int rc;
+  Tcl_Obj *pVarname;
+  Tcl_Obj *pCS;
+  Tcl_Obj *pScript;
+  int isCheckNext = 0;
+
+  if( objc>1 ){
+    char *zOpt = Tcl_GetString(objv[1]);
+    isCheckNext = (strcmp(zOpt, "-next")==0);
+  }
+  if( objc!=4+isCheckNext ){
+    Tcl_WrongNumArgs(interp, 1, objv, "?-next? VARNAME CHANGESET SCRIPT");
+    return TCL_ERROR;
+  }
+
+  pVarname = objv[1+isCheckNext];
+  pCS = objv[2+isCheckNext];
+  pScript = objv[3+isCheckNext];
+
+  pChangeSet = (void *)Tcl_GetByteArrayFromObj(pCS, &nChangeSet);
+  rc = sqlite3changeset_start(&pIter, nChangeSet, pChangeSet);
+  if( rc!=SQLITE_OK ){
+    return test_session_error(interp, rc);
+  }
+
+  while( SQLITE_ROW==sqlite3changeset_next(pIter) ){
+    int nCol;                     /* Number of columns in table */
+    int nCol2;                    /* Number of columns in table */
+    int op;                       /* SQLITE_INSERT, UPDATE or DELETE */
+    const char *zTab;             /* Name of table change applies to */
+    Tcl_Obj *pVar;                /* Tcl value to set $VARNAME to */
+    Tcl_Obj *pOld;                /* Vector of old.* values */
+    Tcl_Obj *pNew;                /* Vector of new.* values */
+    int bIndirect;
+
+    char *zPK;
+    unsigned char *abPK;
+    int i;
+
+    sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
+    pVar = Tcl_NewObj();
+    Tcl_ListObjAppendElement(0, pVar, Tcl_NewStringObj(
+          op==SQLITE_INSERT ? "INSERT" :
+          op==SQLITE_UPDATE ? "UPDATE" : 
+          "DELETE", -1
+    ));
+
+    Tcl_ListObjAppendElement(0, pVar, Tcl_NewStringObj(zTab, -1));
+    Tcl_ListObjAppendElement(0, pVar, Tcl_NewBooleanObj(bIndirect));
+
+    zPK = ckalloc(nCol+1);
+    memset(zPK, 0, nCol+1);
+    sqlite3changeset_pk(pIter, &abPK, &nCol2);
+    assert( nCol==nCol2 );
+    for(i=0; i<nCol; i++){
+      zPK[i] = (abPK[i] ? 'X' : '.');
+    }
+    Tcl_ListObjAppendElement(0, pVar, Tcl_NewStringObj(zPK, -1));
+    ckfree(zPK);
+
+    pOld = Tcl_NewObj();
+    if( op!=SQLITE_INSERT ){
+      int i;
+      for(i=0; i<nCol; i++){
+        sqlite3_value *pVal;
+        sqlite3changeset_old(pIter, i, &pVal);
+        test_append_value(pOld, pVal);
+      }
+    }
+    pNew = Tcl_NewObj();
+    if( op!=SQLITE_DELETE ){
+      int i;
+      for(i=0; i<nCol; i++){
+        sqlite3_value *pVal;
+        sqlite3changeset_new(pIter, i, &pVal);
+        test_append_value(pNew, pVal);
+      }
+    }
+    Tcl_ListObjAppendElement(0, pVar, pOld);
+    Tcl_ListObjAppendElement(0, pVar, pNew);
+
+    Tcl_ObjSetVar2(interp, pVarname, 0, pVar, 0);
+    rc = Tcl_EvalObjEx(interp, pScript, 0);
+    if( rc!=TCL_OK && rc!=TCL_CONTINUE ){
+      sqlite3changeset_finalize(pIter);
+      return rc==TCL_BREAK ? TCL_OK : rc;
+    }
+  }
+
+  if( isCheckNext ){
+    int rc2 = sqlite3changeset_next(pIter);
+    rc = sqlite3changeset_finalize(pIter);
+    assert( (rc2==SQLITE_DONE && rc==SQLITE_OK) || rc2==rc );
+  }else{
+    rc = sqlite3changeset_finalize(pIter);
+  }
+  if( rc!=SQLITE_OK ){
+    return test_session_error(interp, rc);
+  }
+
+  return TCL_OK;
+}
+
+int TestSession_Init(Tcl_Interp *interp){
+  Tcl_CreateObjCommand(interp, "sqlite3session", test_sqlite3session, 0, 0);
+  Tcl_CreateObjCommand(
+      interp, "sqlite3session_foreach", test_sqlite3session_foreach, 0, 0
+  );
+  Tcl_CreateObjCommand(
+      interp, "sqlite3changeset_invert", test_sqlite3changeset_invert, 0, 0
+  );
+  Tcl_CreateObjCommand(
+      interp, "sqlite3changeset_concat", test_sqlite3changeset_concat, 0, 0
+  );
+  Tcl_CreateObjCommand(
+      interp, "sqlite3changeset_apply", test_sqlite3changeset_apply, 0, 0
+  );
+  return TCL_OK;
+}
+
+#endif /* SQLITE_TEST && SQLITE_SESSION && SQLITE_PREUPDATE_HOOK */

main.mk

@@ -47,6 +47,7 @@
 TCCX =  $(TCC) $(OPTS) -I. -I$(TOP)/src -I$(TOP) 
 TCCX += -I$(TOP)/ext/rtree -I$(TOP)/ext/icu -I$(TOP)/ext/fts3
 TCCX += -I$(TOP)/ext/async
+TCCX += -I$(TOP)/ext/session
 
 # Object files for the SQLite library.
 #
@@ -210,6 +211,9 @@ SRC += \
 SRC += \
   $(TOP)/ext/rtree/rtree.h \
   $(TOP)/ext/rtree/rtree.c
+SRC += \
+  $(TOP)/ext/session/sqlite3session.c \
+  $(TOP)/ext/session/sqlite3session.h
 
 
 # Generated source code files
@@ -325,7 +329,9 @@ TESTSRC2 = \
   $(TOP)/ext/fts3/fts3_expr.c \
   $(TOP)/ext/fts3/fts3_tokenizer.c \
   $(TOP)/ext/fts3/fts3_write.c \
-  $(TOP)/ext/async/sqlite3async.c
+  $(TOP)/ext/async/sqlite3async.c \
+  $(TOP)/ext/session/sqlite3session.c \
+  $(TOP)/ext/session/test_session.c
 
 # Header files used by all library source files.
 #
@@ -409,6 +415,7 @@ target_source:	$(SRC) $(TOP)/tool/vdbe-compress.tcl
 sqlite3.c:	target_source $(TOP)/tool/mksqlite3c.tcl
 	tclsh $(TOP)/tool/mksqlite3c.tcl
 	cp tsrc/shell.c tsrc/sqlite3ext.h .
+	cp $(TOP)/ext/session/sqlite3session.h .
 	echo '#ifndef USE_SYSTEM_SQLITE' >tclsqlite3.c
 	cat sqlite3.c >>tclsqlite3.c
 	echo '#endif /* USE_SYSTEM_SQLITE */' >>tclsqlite3.c
@@ -476,7 +483,7 @@ parse.c:	$(TOP)/src/parse.y lemon $(TOP)/addopcodes.awk
 	mv parse.h parse.h.temp
 	$(NAWK) -f $(TOP)/addopcodes.awk parse.h.temp >parse.h
 
-sqlite3.h:	$(TOP)/src/sqlite.h.in $(TOP)/manifest.uuid $(TOP)/VERSION
+sqlite3.h:	$(TOP)/src/sqlite.h.in $(TOP)/manifest.uuid $(TOP)/VERSION $(TOP)/ext/rtree/sqlite3rtree.h
 	tclsh $(TOP)/tool/mksqlite3h.tcl $(TOP) >sqlite3.h
 
 keywordhash.h:	$(TOP)/tool/mkkeywordhash.c
@@ -557,7 +564,8 @@ tclsqlite3:	$(TOP)/src/tclsqlite.c libsqlite3.a
 	$(TCCX) $(TCL_FLAGS) -DTCLSH=1 -o tclsqlite3 \
 		$(TOP)/src/tclsqlite.c libsqlite3.a $(LIBTCL) $(THREADLIB)
 
-sqlite3_analyzer.c: sqlite3.c $(TOP)/src/test_stat.c $(TOP)/src/tclsqlite.c $(TOP)/tool/spaceanal.tcl
+sqlite3_analyzer.c: sqlite3.c $(TOP)/src/test_stat.c $(TOP)/src/tclsqlite.c \
+                    $(TOP)/tool/spaceanal.tcl
 	echo "#define TCLSH 2" > $@
 	cat sqlite3.c $(TOP)/src/test_stat.c $(TOP)/src/tclsqlite.c >> $@
 	echo "static const char *tclsh_main_loop(void){" >> $@
@@ -578,9 +586,11 @@ testfixture$(EXE): $(TESTSRC2) libsqlite3.a $(TESTSRC) $(TOP)/src/tclsqlite.c
 		$(TESTSRC) $(TESTSRC2) $(TOP)/src/tclsqlite.c                \
 		-o testfixture$(EXE) $(LIBTCL) libsqlite3.a $(THREADLIB)
 
-amalgamation-testfixture$(EXE): sqlite3.c $(TESTSRC) $(TOP)/src/tclsqlite.c
+amalgamation-testfixture$(EXE): sqlite3.c $(TESTSRC) $(TOP)/src/tclsqlite.c  \
+				$(TOP)/ext/session/test_session.c
 	$(TCCX) $(TCL_FLAGS) -DTCLSH=1 $(TESTFIXTURE_FLAGS)                  \
 		$(TESTSRC) $(TOP)/src/tclsqlite.c sqlite3.c                  \
+		$(TOP)/ext/session/test_session.c                            \
 		-o testfixture$(EXE) $(LIBTCL) $(THREADLIB)
 
 fts3-testfixture$(EXE): sqlite3.c fts3amal.c $(TESTSRC) $(TOP)/src/tclsqlite.c
@@ -608,7 +618,8 @@ test:	testfixture$(EXE) sqlite3$(EXE)
 # threadtest runs a few thread-safety tests that are implemented in C. This
 # target is invoked by the releasetest.tcl script.
 # 
-threadtest3$(EXE): sqlite3.o $(TOP)/test/threadtest3.c $(TOP)/test/tt3_checkpoint.c
+threadtest3$(EXE): sqlite3.o $(TOP)/test/threadtest3.c \
+                   $(TOP)/test/tt3_checkpoint.c
 	$(TCCX) -O2 sqlite3.o $(TOP)/test/threadtest3.c \
 		-o threadtest3$(EXE) $(THREADLIB)
 

manifest

@@ -1,9 +1,9 @@
-C Use\sOP_Copy\sinstead\sof\sOP_SCopy\swhen\smoving\sresults\sout\sof\sa\ssubquery,\nto\sprevent\sthe\ssubquery\sresults\sfrom\schanging\sout\sfrom\sunder\sthe\souter\nquery.\s\sFix\sfor\sticket\s[1e64dd782a126f48d78].
-D 2014-04-03T16:29:31.330
+C TCL\stests\snow\sall\spass.
+D 2014-04-16T17:15:14.114
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
-F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
+F Makefile.in e4ee6d36cdf6136aee0158675a3b24dd3bf31a5a
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
-F Makefile.msc fdacba6fb574868c71fde6db6b77789a383a4c19
+F Makefile.msc b448317831d9c364bf501538becce5cc1f0a0f8b
 F Makefile.vxworks db21ed42a01d5740e656b16f92cb5d8d5e5dd315
 F README.md 64f270c43c38c46de749e419c22f0ae2f4499fe8
 F VERSION 9f823c026c6a32fc5f84d212a8aae0a221dba45c
@@ -120,7 +120,7 @@ F ext/misc/vfslog.c fe40fab5c077a40477f7e5eba994309ecac6cc95
 F ext/misc/vtshim.c babb0dc2bf116029e3e7c9a618b8a1377045303e
 F ext/misc/wholenumber.c 784b12543d60702ebdd47da936e278aa03076212
 F ext/rtree/README 6315c0d73ebf0ec40dedb5aa0e942bc8b54e3761
-F ext/rtree/rtree.c 2d9f95da404d850474e628c720c5ce15d29b47de
+F ext/rtree/rtree.c 142d70dc3bb8db1caf6c0e94b88ec0e8047d36ee
 F ext/rtree/rtree.h 834dbcb82dc85b2481cde6a07cdadfddc99e9b9e
 F ext/rtree/rtree1.test cf679265ecafff494a768ac9c2f43a70915a6290
 F ext/rtree/rtree2.test acbb3a4ce0f4fbc2c304d2b4b784cfa161856bba
@@ -132,18 +132,32 @@ F ext/rtree/rtree7.test 1fa710b9e6bf997a0c1a537b81be7bb6fded1971
 F ext/rtree/rtree8.test db79c812f9e4a11f9b1f3f9934007884610a713a
 F ext/rtree/rtree9.test d86ebf08ff6328895613ed577dd8a2a37c472c34
 F ext/rtree/rtreeA.test ace05e729a36e342d40cf94e9efc7b4723d9dcdf
-F ext/rtree/rtreeB.test 983e567b49b5dca165940f66b87e161aa30e82b2
+F ext/rtree/rtreeB.test c85f9ce78766c4e68b8b89fbf2979ee9cfa82b4e
 F ext/rtree/rtreeC.test 16d7aa86ecb6a876d2a38cf590a1471a41b3a46d
 F ext/rtree/rtreeD.test 636630357638f5983701550b37f0f5867130d2ca
 F ext/rtree/rtree_perf.tcl 6c18c1f23cd48e0f948930c98dfdd37dfccb5195
 F ext/rtree/rtree_util.tcl 06aab2ed5b826545bf215fff90ecb9255a8647ea
-F ext/rtree/sqlite3rtree.h c34c1e41d1ab80bb8ad09aae402c9c956871a765
+F ext/rtree/sqlite3rtree.h 488cf8834d2012b913d33683157d3cf5f1327a69
 F ext/rtree/tkt3363.test 142ab96eded44a3615ec79fba98c7bde7d0f96de
 F ext/rtree/viewrtree.tcl eea6224b3553599ae665b239bd827e182b466024
+F ext/session/session1.test 894e3bc9f497c4fa07a2aa3271e3911f3670c3d8
+F ext/session/session2.test 99ca0da7ddb617d42bafd83adccf99f18ae0384b
+F ext/session/session3.test a7a9ce59b8d1e49e2cc23d81421ac485be0eea01
+F ext/session/session4.test a6ed685da7a5293c5d6f99855bcf41dbc352ca84
+F ext/session/session5.test 8fdfaf9dba28a2f1c6b89b06168bdab1fef2d478
+F ext/session/session6.test 443789bc2fca12e4f7075cf692c60b8a2bea1a26
+F ext/session/session8.test 7d35947ad329b8966f095d34f9617a9eff52dc65
+F ext/session/session9.test 776e46785c29c11cda01f5205d0f1e8f8f9a46bf
+F ext/session/sessionA.test eb05c13e4ef1ca8046a3a6dbf2d5f6f5b04a11d4
+F ext/session/session_common.tcl 1539d8973b2aea0025c133eb0cc4c89fcef541a5
+F ext/session/sessionfault.test 496291b287ba3c0b14ca2e074425e29cc92a64a6
+F ext/session/sqlite3session.c 34e19186d05d534e5a37a4f5a8a3c3e24e3fa88a
+F ext/session/sqlite3session.h 6c35057241567ed6319f750ee504a81c459225e1
+F ext/session/test_session.c 7878ac0e2fe9675e8ec24d54f6a538ccc105977f
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
 F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
 F magic.txt f439556c5ce01ced70987e5ee86549a45165d9ff
-F main.mk 3ae543fa446525c1dec55f58de67f41b78651812
+F main.mk 82b154dd823b75c2f1247f1bb98893bf94a5af57
 F mkopcodec.awk c2ff431854d702cdd2d779c9c0d1f58fa16fa4ea
 F mkopcodeh.awk c6b3fa301db6ef7ac916b14c60868aeaec1337b5
 F mkso.sh fd21c06b063bb16a5d25deea1752c2da6ac3ed83
@@ -172,7 +186,7 @@ F src/callback.c 174e3c8656bc29f91d710ab61550d16eea34be98
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 0231df905e2c4abba4483ee18ffc05adc321df2a
 F src/date.c 593c744b2623971e45affd0bde347631bdfa4625
-F src/delete.c cdd57149543bb28304d8f717c243f2a86b1fc280
+F src/delete.c 19df05f1ab55f021605e1c7a3c0a3851876fb3c7
 F src/expr.c da2b3cb41081af6b56e95e7c9e95949564ce2e21
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c 5269ef07b100763134f71b889327c333bd0989cf
@@ -181,12 +195,12 @@ F src/global.c 1d7bb7ea8254ae6a68ed9bfaf65fcb3d1690b486
 F src/hash.c d139319967164f139c8d1bb8a11b14db9c4ba3cd
 F src/hash.h 8890a25af81fb85a9ad7790d32eedab4b994da22
 F src/hwtime.h d32741c8f4df852c7d959236615444e2b1063b08
-F src/insert.c d8bb30535c8c0785876025a4a07f9074640a15d1
+F src/insert.c e1ebd5d798da6b8dc180841c34e3c91b4d1fb798
 F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d
 F src/legacy.c 0df0b1550b9cc1f58229644735e317ac89131f12
 F src/lempar.c cdf0a000315332fc9b50b62f3b5e22e080a0952b
 F src/loadext.c 867c7b330b740c6c917af9956b13b81d0a048303
-F src/main.c 691b25754bef596108fe60ff1bcbe8445369c9db
+F src/main.c 81453a961f9096bf0eb76a48d82c0f0509d62bf0
 F src/malloc.c 0203ebce9152c6a0e5de520140b8ba65187350be
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c c0c990fcaddff810ea277b4fb5d9138603dd5d4b
@@ -219,14 +233,14 @@ F src/resolve.c 273d5f47c4e2c05b2d3d2bffeda939551ab59e66
 F src/rowset.c 64655f1a627c9c212d9ab497899e7424a34222e0
 F src/select.c 269c3e31a450fce642a10569221a49180348c88e
 F src/shell.c 5260f2ada8dd06e9f5ae0a448c8c01e7a75dd881
-F src/sqlite.h.in a2ef671f92747a5a1c8a47bad5c585a8dd9eca80
+F src/sqlite.h.in a31c8b7782a0388b4bd823ed3a3a3e4b93b0cf42
 F src/sqlite3.rc 11094cc6a157a028b301a9f06b3d03089ea37c3e
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
-F src/sqliteInt.h cc9582a91b2910404ccda7b7e198815ea0f75948
+F src/sqliteInt.h 2ce2e12bc5a4cf8e5511ee11ee4778a1911be7e9
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac05a5c7017d0b9f0b4bcd701228b784f987158
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
-F src/tclsqlite.c e87c99e28a145943666b51b212dacae35fcea0bd
+F src/tclsqlite.c 7ada527ce7916adcabad7997c10f09680aac7c9b
 F src/test1.c 2401eee14a4309a7cfe2aeb2f30ad517a1d9c299
 F src/test2.c 7355101c085304b90024f2261e056cdff13c6c35
 F src/test3.c 1c0e5d6f080b8e33c1ce8b3078e7013fdbcd560c
@@ -240,7 +254,7 @@ F src/test_async.c 21e11293a2f72080eda70e1124e9102044531cd8
 F src/test_autoext.c dea8a01a7153b9adc97bd26161e4226329546e12
 F src/test_backup.c 3875e899222b651e18b662f86e0e50daa946344e
 F src/test_btree.c 5b89601dcb42a33ba8b820a6b763cc9cb48bac16
-F src/test_config.c 0336e0bdbe541b4af89d7e3dd0656e8e6b51e585
+F src/test_config.c b131030783f4328beb7008dbfe7392c7f086abc7
 F src/test_demovfs.c 69b2085076654ebc18014cbc6386f04409c959a9
 F src/test_devsym.c e7498904e72ba7491d142d5c83b476c4e76993bc
 F src/test_fs.c ced436e3d4b8e4681328409b8081051ce614e28f
@@ -260,7 +274,7 @@ F src/test_osinst.c 90a845c8183013d80eccb1f29e8805608516edba
 F src/test_pcache.c a5cd24730cb43c5b18629043314548c9169abb00
 F src/test_quota.c 30c64f0ef84734f2231a686df41ed882b0c59bc0
 F src/test_quota.h 8761e463b25e75ebc078bd67d70e39b9c817a0cb
-F src/test_rtree.c f3d1d12538dccb75fd916e3fa58f250edbdd3b47
+F src/test_rtree.c cd35d54c0b847c0c373d66f91616c49697ab4edf
 F src/test_schema.c cd12a2223c3a394f4d07bb93bdf6d344c5c121b6
 F src/test_server.c a2615049954cbb9cfb4a62e18e2f0616e4dc38fe
 F src/test_sqllog.c c1c1bbedbcaf82b93d83e4f9dd990e62476a680e
@@ -274,16 +288,16 @@ F src/test_vfstrace.c 3a0ab304682fecbceb689e7d9b904211fde11d78
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/tokenize.c 6da2de6e12218ccb0aea5184b56727d011f4bee7
 F src/trigger.c 66f3470b03b52b395e839155786966e3e037fddb
-F src/update.c 5b3e74a03b3811e586b4f2b4cbd7c49f01c93115
+F src/update.c 7bb549d61efc6853f5cc708c1de6931179f8a12d
 F src/utf.c 6dc9ec9f1b3db43ae8ba0365377f11df1ee4c01c
 F src/util.c c46c90459ef9bdc0c6c73803cf4c55425b4771cf
 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
-F src/vdbe.c e811a0081149fb90db367026d154cd7efb3c7098
-F src/vdbe.h 394464909ed682334aa3d5831aae0c2fe2abef94
-F src/vdbeInt.h e6d83e5bfd62fc6685ba1ed6153f7099f82de9f7
-F src/vdbeapi.c 0ed6053f947edd0b30f64ce5aeb811872a3450a4
-F src/vdbeaux.c 1153175fb57a8454e1c8cf79b59b7bf92b26779d
-F src/vdbeblob.c 15377abfb59251bccedd5a9c7d014a895f0c04aa
+F src/vdbe.c 47bdf5f82fa23548bc0ee720c54e3b2b8802babe
+F src/vdbe.h d03fcf47890ae1c79a335ca994cb878b302697ca
+F src/vdbeInt.h c05d4572211384c560b7579e7a299248cf31d6bd
+F src/vdbeapi.c d3c662762b62e330a03f29de8e2ac7098ef78030
+F src/vdbeaux.c f9c225c26b4cab6239a7790b4bd14a6cd96ba19e
+F src/vdbeblob.c 2d1f0fdb0f5b72118520980360a594b1c30cbdd8
 F src/vdbemem.c 6fc77594c60f6155404f3f8d71bf36d1fdeb4447
 F src/vdbesort.c 4abb7c0f8f19b7d7d82f4558d5da1a30fdf9ea38
 F src/vdbetrace.c 6f52bc0c51e144b7efdcfb2a8f771167a8816767
@@ -468,7 +482,7 @@ F test/fkey2.test 32ca728bcb854feed72d1406ea375fe423eebff2
 F test/fkey3.test 76d475c80b84ee7a5d062e56ccb6ea68882e2b49
 F test/fkey4.test 86446017011273aad8f9a99c1a65019e7bd9ca9d
 F test/fkey5.test 8a1fde4e7721ae00b05b3178888833726ca2df8d
-F test/fkey6.test abb59f866c1b44926fd02d1fdd217d831fe04f48
+F test/fkey6.test 6697550baa38505c9952eff130ab26a2d156c0cc
 F test/fkey7.test e31d0e71a41c1d29349a16448d6c420e2c53a8fc
 F test/fkey_malloc.test 594a7ea1fbab553c036c70813cd8bd9407d63749
 F test/format4.test 1f0cac8ff3895e9359ed87e41aaabee982a812eb
@@ -588,7 +602,7 @@ F test/fuzz_malloc.test 328f70aaca63adf29b4c6f06505ed0cf57ca7c26
 F test/fuzzer1.test d4c52aaf3ef923da293a2653cfab33d02f718a36
 F test/fuzzerfault.test 8792cd77fd5bce765b05d0c8e01b9edcf8af8536
 F test/genesis.tcl 1e2e2e8e5cc4058549a154ff1892fe5c9de19f98
-F test/hook.test 162d7cef7a2d2b04839fe14402934e6a1b79442f
+F test/hook.test 5429d34d6e59086175d8efbcd7e14d891375bdfb
 F test/icu.test 70df4faca133254c042d02ae342c0a141f2663f4
 F test/in.test 047c4671328e9032ab95666a67021adbbd36e98e
 F test/in2.test 5d4c61d17493c832f7d2d32bef785119e87bde75
@@ -737,7 +751,7 @@ F test/pagesize.test 1dd51367e752e742f58e861e65ed7390603827a0
 F test/pcache.test b09104b03160aca0d968d99e8cd2c5b1921a993d
 F test/pcache2.test a83efe2dec0d392f814bfc998def1d1833942025
 F test/percentile.test b98fc868d71eb5619d42a1702e9ab91718cbed54
-F test/permutations.test 40add071ba71aefe1c04f5845308cf46f7de8d04
+F test/permutations.test b7b8b410e3d22e616ff473e588078da6a377c082
 F test/pragma.test adb21a90875bc54a880fa939c4d7c46598905aa0
 F test/pragma2.test aea7b3d82c76034a2df2b38a13745172ddc0bc13
 F test/printf.test ec9870c4dce8686a37818e0bf1aba6e6a1863552
@@ -793,6 +807,7 @@ F test/selectD.test b0f02a04ef7737decb24e08be2c39b9664b43394
 F test/selectE.test fc02a1eb04c8eb537091482644b7d778ae8759b7
 F test/selectF.test 21c94e6438f76537b72532fa9fd4710cdd455fc3
 F test/server1.test 46803bd3fe8b99b30dbc5ff38ffc756f5c13a118
+F test/session.test 082dea459efc76e2a527b8ee9ff74d76e63ea7b6
 F test/shared.test 1da9dbad400cee0d93f252ccf76e1ae007a63746
 F test/shared2.test 03eb4a8d372e290107d34b6ce1809919a698e879
 F test/shared3.test fcd65cb11d189eff5f5c85cc4fad246fb0933108
@@ -810,6 +825,7 @@ F test/shell3.test 5e8545ec72c4413a0e8d4c6be56496e3c257ca29
 F test/shell4.test aa4eef8118b412d1a01477a53426ece169ea86a9
 F test/shell5.test bb755ea9144b8078a752fc56223582627070b5f1
 F test/shortread1.test bb591ef20f0fd9ed26d0d12e80eee6d7ac8897a3
+F test/show_speedtest1_rtree.tcl 32e6c5f073d7426148a6936a0408f4b5b169aba5
 F test/shrink.test 8c70f62b6e8eb4d54533de6d65bd06b1b9a17868
 F test/sidedelete.test f0ad71abe6233e3b153100f3b8d679b19a488329
 F test/skipscan1.test bed8cbe9d554c8c27afb6c88500f704c86a9196f
@@ -825,7 +841,7 @@ F test/speed3.test d32043614c08c53eafdc80f33191d5bd9b920523
 F test/speed4.test abc0ad3399dcf9703abed2fff8705e4f8e416715
 F test/speed4p.explain 6b5f104ebeb34a038b2f714150f51d01143e59aa
 F test/speed4p.test 0e51908951677de5a969b723e03a27a1c45db38b
-F test/speedtest1.c 90446861e566a9965a8d005381a3c964ff333646
+F test/speedtest1.c d29c8048beb7ea9254191f3fde9414709166a920
 F test/spellfix.test 61309f5efbec53603b3f86457d34a504f80abafe
 F test/sqllimits1.test b1aae27cc98eceb845e7f7adf918561256e31298
 F test/stat.test 76fd746b85459e812a0193410fb599f0531f22de
@@ -841,11 +857,11 @@ F test/sysfault.test fa776e60bf46bdd3ae69f0b73e46ee3977a58ae6
 F test/table.test 580d23530187026d4502fae74a490f0408cf2cc7
 F test/tableapi.test 2674633fa95d80da917571ebdd759a14d9819126
 F test/tableopts.test dba698ba97251017b7c80d738c198d39ab747930
-F test/tclsqlite.test 37a61c2da7e3bfe3b8c1a2867199f6b860df5d43
+F test/tclsqlite.test a7308276aad2e6c0bfb5b0414424dd0d9cc0cad7
 F test/tempdb.test 19d0f66e2e3eeffd68661a11c83ba5e6ace9128c
 F test/temptable.test d2c9b87a54147161bcd1822e30c1d1cd891e5b30
 F test/temptrigger.test 8ec228b0db5d7ebc4ee9b458fc28cb9e7873f5e1
-F test/tester.tcl f31bea1483ea1d39620f982130026e76f872d744
+F test/tester.tcl 8bab16cd983b4207203d82b7de229aa7b457f575
 F test/thread001.test 9f22fd3525a307ff42a326b6bc7b0465be1745a5
 F test/thread002.test e630504f8a06c00bf8bbe68528774dd96aeb2e58
 F test/thread003.test ee4c9efc3b86a6a2767516a37bd64251272560a7
@@ -1128,8 +1144,8 @@ F tool/mkopts.tcl 66ac10d240cc6e86abd37dc908d50382f84ff46e
 F tool/mkpragmatab.tcl 78a77b2c554d534c6f2dc903130186ed15715460
 F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
 F tool/mksqlite3c-noext.tcl 8bce31074e4cbe631bb7676526a048335f4c9f02
-F tool/mksqlite3c.tcl ed5b4e9ca8bf209ff401059a16362f37710fd8b8
-F tool/mksqlite3h.tcl ba24038056f51fde07c0079c41885ab85e2cff12
+F tool/mksqlite3c.tcl 3a7297ac69e6da8089eeb3d3ba986e0e3d6016f4
+F tool/mksqlite3h.tcl 2d0f1b3768f8d000b7881217d5fd4c776eb27467
 F tool/mksqlite3internalh.tcl 3dca7bb5374cee003379b8cbac73714f610ef795
 F tool/mkvsix.tcl 6477fb9dab838b7eea1eed50658ff1cda04850b5
 F tool/offsets.c fe4262fdfa378e8f5499a42136d17bf3b98f6091
@@ -1152,15 +1168,14 @@ F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/stack_usage.tcl f8e71b92cdb099a147dad572375595eae55eca43
 F tool/symbols-mingw.sh 4dbcea7e74768305384c9fd2ed2b41bbf9f0414d
-F tool/symbols.sh fec58532668296d7c7dc48be9c87f75ccdb5814f
+F tool/symbols.sh c5a617b8c61a0926747a56c65f5671ef8ac0e148
 F tool/tostr.awk e75472c2f98dd76e06b8c9c1367f4ab07e122d06
 F tool/vdbe-compress.tcl 0cf56e9263a152b84da86e75a5c0cdcdb7a47891
 F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P 48ecdd4aff03741f96c070dced69c3c273b652cb
-Q +ec6a06246e04eee5f25f1c28507df73b697099c0
-R b6a2fefa5b61ea0e64da4db2aaa10286
+P 5b0e6ba4a5050cf81cf41b977b28d714163569e0
+R f6b681e4a8814b2c282cb2ca3c357703
 U drh
-Z f1f1ceb5f31f4e26d736a13a2a5aca0f
+Z 3d7f5774712bc082940f713cae866e31

manifest.uuid

@@ -1 +1 @@
-d5513dfa23baa0b0a095aaf17d19aacd30dcef61
+f864baccd3fe0ee939ac1ec20069792f649cddc0

src/delete.c

@@ -358,8 +358,15 @@ void sqlite3DeleteFrom(
   /* Special case: A DELETE without a WHERE clause deletes everything.
   ** It is easier just to erase the whole table. Prior to version 3.6.5,
   ** this optimization caused the row change count (the value returned by 
-  ** API function sqlite3_count_changes) to be set incorrectly.  */
-  if( rcauth==SQLITE_OK && pWhere==0 && !pTrigger && !IsVirtual(pTab) 
+  ** API function sqlite3_count_changes) to be set incorrectly.
+  */
+  if( rcauth==SQLITE_OK
+   && pWhere==0
+   && !pTrigger
+   && !IsVirtual(pTab) 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+   && db->xPreUpdateCallback==0
+#endif
    && 0==sqlite3FkRequired(pParse, pTab, 0, 0)
   ){
     assert( !isView );
@@ -669,13 +676,18 @@ void sqlite3GenerateRowDelete(
 
   /* Delete the index and table entries. Skip this step if pTab is really
   ** a view (in which case the only effect of the DELETE statement is to
-  ** fire the INSTEAD OF triggers).  */ 
+  ** fire the INSTEAD OF triggers).  
+  **
+  ** If variable 'count' is non-zero, then this OP_Delete instruction should
+  ** invoke the update-hook. The pre-update-hook, on the other hand should
+  ** be invoked unless table pTab is a system table. The difference is that
+  ** the update-hook is not invoked for rows removed by REPLACE, but the 
+  ** pre-update-hook is.
+  */ 
   if( pTab->pSelect==0 ){
     sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);
     sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, (count?OPFLAG_NCHANGE:0));
-    if( count ){
-      sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
-    }
+    sqlite3VdbeChangeP4(v, -1, (char*)pTab, P4_TABLE);
   }
 
   /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to

src/insert.c

@@ -1331,9 +1331,21 @@ void sqlite3GenerateConstraintChecks(
           sqlite3MultiWrite(pParse);
           sqlite3GenerateRowDelete(pParse, pTab, pTrigger, iDataCur, iIdxCur,
                                    regNewData, 1, 0, OE_Replace, 1);
-        }else if( pTab->pIndex ){
-          sqlite3MultiWrite(pParse);
-          sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);
+        }else{
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+          if( HasRowid(pTab) ){
+            /* This OP_Delete opcode fires the pre-update-hook only. It does
+            ** not modify the b-tree. It is more efficient to let the coming
+            ** OP_Insert replace the existing entry than it is to delete the
+            ** existing entry and then insert a new one. */
+            sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, OPFLAG_ISNOOP);
+            sqlite3VdbeChangeP4(v, -1, (char *)pTab, P4_TABLE);
+          }
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+          if( pTab->pIndex ){
+            sqlite3MultiWrite(pParse);
+            sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, 0);
+          }
         }
         seenReplace = 1;
         break;
@@ -1589,7 +1601,7 @@ void sqlite3CompleteInsertion(
   }
   sqlite3VdbeAddOp3(v, OP_Insert, iDataCur, regRec, regNewData);
   if( !pParse->nested ){
-    sqlite3VdbeChangeP4(v, -1, pTab->zName, P4_TRANSIENT);
+    sqlite3VdbeChangeP4(v, -1, (char *)pTab, P4_TABLE);
   }
   sqlite3VdbeChangeP5(v, pik_flags);
 }
@@ -1965,7 +1977,7 @@ static int xferOptimization(
     sqlite3VdbeAddOp2(v, OP_RowData, iSrc, regData);
     sqlite3VdbeAddOp3(v, OP_Insert, iDest, regData, regRowid);
     sqlite3VdbeChangeP5(v, OPFLAG_NCHANGE|OPFLAG_LASTROWID|OPFLAG_APPEND);
-    sqlite3VdbeChangeP4(v, -1, pDest->zName, 0);
+    sqlite3VdbeChangeP4(v, -1, (char*)pDest, P4_TABLE);
     sqlite3VdbeAddOp2(v, OP_Next, iSrc, addr1); VdbeCoverage(v);
     sqlite3VdbeAddOp2(v, OP_Close, iSrc, 0);
     sqlite3VdbeAddOp2(v, OP_Close, iDest, 0);

src/main.c

@@ -1650,6 +1650,27 @@ void *sqlite3_rollback_hook(
   return pRet;
 }
 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Register a callback to be invoked each time a row is updated,
+** inserted or deleted using this database connection.
+*/
+void *sqlite3_preupdate_hook(
+  sqlite3 *db,              /* Attach the hook to this database */
+  void(*xCallback)(         /* Callback function */
+    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
+  void *pArg                /* First callback argument */
+){
+  void *pRet;
+  sqlite3_mutex_enter(db->mutex);
+  pRet = db->pPreUpdateArg;
+  db->xPreUpdateCallback = xCallback;
+  db->pPreUpdateArg = pArg;
+  sqlite3_mutex_leave(db->mutex);
+  return pRet;
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 #ifndef SQLITE_OMIT_WAL
 /*
 ** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().

src/sqlite.h.in

@@ -4907,8 +4907,8 @@ void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
 ** on the same [database connection] D, or NULL for
 ** the first call on D.
 **
-** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()]
-** interfaces.
+** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
+** and [sqlite3_preupdate_hook()] interfaces.
 */
 void *sqlite3_update_hook(
   sqlite3*, 
@@ -6348,7 +6348,7 @@ int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
 ** database file in rollback mode databases. Any pages written as part of
 ** transaction rollback or database recovery operations are not included.
 ** If an IO or other error occurs while writing a page to disk, the effect
-** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
+** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined). ^The
 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
 ** </dd>
 **
@@ -7306,6 +7306,101 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 
 
 
+/*
+** CAPI3REF: The pre-update hook.
+** EXPERIMENTAL
+**
+** ^These interfaces are only available if SQLite is compiled using the
+** [SQLITE_ENABLE_UPDATE_HOOK] compile-time option.
+**
+** ^The [sqlite3_preupdate_hook()] interface registers a callback function
+** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation.
+** ^At most one preupdate hook may be registered at a time on a single
+** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
+** the previous setting.
+** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
+** with a NULL pointer as the second parameter.
+** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
+** the first parameter to callbacks.
+**
+** ^The preupdate hook only fires for changes to real tables; the preupdate
+** hook is not invoked for changes to virtual tables.
+**
+** ^The second parameter to the preupdate callback is a pointer to
+** the [database connection] that registered the preupdate hook.
+** ^The third parameter to the preupdate callback is one of the constants
+** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to indentify the
+** kind of update operation that is about to occur.
+** ^(The fourth parameter to the preupdate callback is the name of the
+** database within the database connection that is being modified.  This
+** will be "main" for the main database or "temp" for TEMP tables or 
+** the name given after the AS keyword in the [ATTACH] statement for attached
+** databases.)^
+** ^The fifth parameter to the preupdate callback is the name of the
+** table that is being modified.
+** ^The sixth parameter to the preupdate callback is the initial [rowid] of the
+** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is
+** undefined for SQLITE_INSERT changes.
+** ^The seventh parameter to the preupdate callback is the final [rowid] of
+** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is
+** undefined for SQLITE_DELETE changes.
+**
+** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
+** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
+** provide additional information about a preupdate event. These routines
+** may only be called from within a preupdate callback.  Invoking any of
+** these routines from outside of a preupdate callback or with a
+** [database connection] pointer that is different from the one supplied
+** to the preupdate callback results in undefined and probably undesirable
+** behavior.
+**
+** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
+** in the row that is being inserted, updated, or deleted.
+**
+** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
+** a [protected sqlite3_value] that contains the value of the Nth column of
+** the table row before it is updated.  The N parameter must be between 0
+** and one less than the number of columns or the behavior will be
+** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
+** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
+** behavior is undefined.  The [sqlite3_value] that P points to
+** will be destroyed when the preupdate callback returns.
+**
+** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
+** a [protected sqlite3_value] that contains the value of the Nth column of
+** the table row after it is updated.  The N parameter must be between 0
+** and one less than the number of columns or the behavior will be
+** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
+** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
+** behavior is undefined.  The [sqlite3_value] that P points to
+** will be destroyed when the preupdate callback returns.
+**
+** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
+** callback was invoked as a result of a direct insert, update, or delete
+** operation; or 1 for inserts, updates, or deletes invoked by top-level 
+** triggers; or 2 for changes resulting from triggers called by top-level
+** triggers; and so forth.
+**
+** See also:  [sqlite3_update_hook()]
+*/
+SQLITE_EXPERIMENTAL void *sqlite3_preupdate_hook(
+  sqlite3 *db,
+  void(*xPreUpdate)(
+    void *pCtx,                   /* Copy of third arg to preupdate_hook() */
+    sqlite3 *db,                  /* Database handle */
+    int op,                       /* SQLITE_UPDATE, DELETE or INSERT */
+    char const *zDb,              /* Database name */
+    char const *zName,            /* Table name */
+    sqlite3_int64 iKey1,          /* Rowid of row about to be deleted/updated */
+    sqlite3_int64 iKey2           /* New rowid value (for a rowid UPDATE) */
+  ),
+  void*
+);
+SQLITE_EXPERIMENTAL int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
+SQLITE_EXPERIMENTAL int sqlite3_preupdate_count(sqlite3 *);
+SQLITE_EXPERIMENTAL int sqlite3_preupdate_depth(sqlite3 *);
+SQLITE_EXPERIMENTAL int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
+
 /*
 ** Undo the hack that converts floating point types to integer for
 ** builds on processors without floating point support.

src/sqliteInt.h

@@ -784,6 +784,7 @@ typedef struct LookasideSlot LookasideSlot;
 typedef struct Module Module;
 typedef struct NameContext NameContext;
 typedef struct Parse Parse;
+typedef struct PreUpdate PreUpdate;
 typedef struct PrintfArguments PrintfArguments;
 typedef struct RowSet RowSet;
 typedef struct Savepoint Savepoint;
@@ -989,6 +990,13 @@ struct sqlite3 {
   void (*xRollbackCallback)(void*); /* Invoked at every commit. */
   void *pUpdateArg;
   void (*xUpdateCallback)(void*,int, const char*,const char*,sqlite_int64);
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  void *pPreUpdateArg;          /* First argument to xPreUpdateCallback */
+  void (*xPreUpdateCallback)(   /* Registered using sqlite3_preupdate_hook() */
+    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64
+  );
+  PreUpdate *pPreUpdate;        /* Context for active pre-update callback */
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
 #ifndef SQLITE_OMIT_WAL
   int (*xWalCallback)(void *, sqlite3 *, const char *, int);
   void *pWalArg;
@@ -2507,6 +2515,9 @@ struct AuthContext {
 
 /*
 ** Bitfield flags for P5 value in various opcodes.
+**
+** Note that the values for ISNOOP and LENGTHARG are the same.  But as 
+** those bits are never used on the same opcode, the overlap is harmless.
 */
 #define OPFLAG_NCHANGE       0x01    /* Set to update db->nChange */
 #define OPFLAG_LASTROWID     0x02    /* Set to update db->lastRowid */
@@ -2514,6 +2525,7 @@ struct AuthContext {
 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
 #define OPFLAG_CLEARCACHE    0x20    /* Clear pseudo-table cache in OP_Column */
+#define OPFLAG_ISNOOP        0x40    /* OP_Delete does pre-update-hook only */
 #define OPFLAG_LENGTHARG     0x40    /* OP_Column only used for length() */
 #define OPFLAG_TYPEOFARG     0x80    /* OP_Column only used for typeof() */
 #define OPFLAG_BULKCSR       0x01    /* OP_Open** used to open bulk cursor */

src/tclsqlite.c

@@ -132,6 +132,7 @@ struct SqliteDb {
   char *zNull;               /* Text to substitute for an SQL NULL value */
   SqlFunc *pFunc;            /* List of SQL functions */
   Tcl_Obj *pUpdateHook;      /* Update hook script (if any) */
+  Tcl_Obj *pPreUpdateHook;   /* Pre-update hook script (if any) */
   Tcl_Obj *pRollbackHook;    /* Rollback hook script (if any) */
   Tcl_Obj *pWalHook;         /* WAL hook script (if any) */
   Tcl_Obj *pUnlockNotify;    /* Unlock notify script (if any) */
@@ -510,6 +511,9 @@ static void DbDeleteCmd(void *db){
   if( pDb->pUpdateHook ){
     Tcl_DecrRefCount(pDb->pUpdateHook);
   }
+  if( pDb->pPreUpdateHook ){
+    Tcl_DecrRefCount(pDb->pPreUpdateHook);
+  }
   if( pDb->pRollbackHook ){
     Tcl_DecrRefCount(pDb->pRollbackHook);
   }
@@ -676,6 +680,42 @@ static void DbUnlockNotify(void **apArg, int nArg){
 }
 #endif
 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Pre-update hook callback.
+*/
+static void DbPreUpdateHandler(
+  void *p, 
+  sqlite3 *db,
+  int op,
+  const char *zDb, 
+  const char *zTbl, 
+  sqlite_int64 iKey1,
+  sqlite_int64 iKey2
+){
+  SqliteDb *pDb = (SqliteDb *)p;
+  Tcl_Obj *pCmd;
+  static const char *azStr[] = {"DELETE", "INSERT", "UPDATE"};
+
+  assert( (SQLITE_DELETE-1)/9 == 0 );
+  assert( (SQLITE_INSERT-1)/9 == 1 );
+  assert( (SQLITE_UPDATE-1)/9 == 2 );
+  assert( pDb->pPreUpdateHook );
+  assert( db==pDb->db );
+  assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );
+
+  pCmd = Tcl_DuplicateObj(pDb->pPreUpdateHook);
+  Tcl_IncrRefCount(pCmd);
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(azStr[(op-1)/9], -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(zDb, -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(zTbl, -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewWideIntObj(iKey1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewWideIntObj(iKey2));
+  Tcl_EvalObjEx(pDb->interp, pCmd, TCL_EVAL_DIRECT);
+  Tcl_DecrRefCount(pCmd);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 static void DbUpdateHandler(
   void *p, 
   int op,
@@ -685,14 +725,18 @@ static void DbUpdateHandler(
 ){
   SqliteDb *pDb = (SqliteDb *)p;
   Tcl_Obj *pCmd;
+  static const char *azStr[] = {"DELETE", "INSERT", "UPDATE"};
+
+  assert( (SQLITE_DELETE-1)/9 == 0 );
+  assert( (SQLITE_INSERT-1)/9 == 1 );
+  assert( (SQLITE_UPDATE-1)/9 == 2 );
 
   assert( pDb->pUpdateHook );
   assert( op==SQLITE_INSERT || op==SQLITE_UPDATE || op==SQLITE_DELETE );
 
   pCmd = Tcl_DuplicateObj(pDb->pUpdateHook);
   Tcl_IncrRefCount(pCmd);
-  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(
-    ( (op==SQLITE_INSERT)?"INSERT":(op==SQLITE_UPDATE)?"UPDATE":"DELETE"), -1));
+  Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(azStr[(op-1)/9], -1));
   Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(zDb, -1));
   Tcl_ListObjAppendElement(0, pCmd, Tcl_NewStringObj(zTbl, -1));
   Tcl_ListObjAppendElement(0, pCmd, Tcl_NewWideIntObj(rowid));
@@ -1598,6 +1642,46 @@ static int DbEvalNextCmd(
   return rc;
 }
 
+/*
+** This function is used by the implementations of the following database 
+** handle sub-commands:
+**
+**   $db update_hook ?SCRIPT?
+**   $db wal_hook ?SCRIPT?
+**   $db commit_hook ?SCRIPT?
+**   $db preupdate hook ?SCRIPT?
+*/
+static void DbHookCmd(
+  Tcl_Interp *interp,             /* Tcl interpreter */
+  SqliteDb *pDb,                  /* Database handle */
+  Tcl_Obj *pArg,                  /* SCRIPT argument (or NULL) */
+  Tcl_Obj **ppHook                /* Pointer to member of SqliteDb */
+){
+  sqlite3 *db = pDb->db;
+
+  if( *ppHook ){
+    Tcl_SetObjResult(interp, *ppHook);
+    if( pArg ){
+      Tcl_DecrRefCount(*ppHook);
+      *ppHook = 0;
+    }
+  }
+  if( pArg ){
+    assert( !(*ppHook) );
+    if( Tcl_GetCharLength(pArg)>0 ){
+      *ppHook = pArg;
+      Tcl_IncrRefCount(*ppHook);
+    }
+  }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  sqlite3_preupdate_hook(db, (pDb->pPreUpdateHook?DbPreUpdateHandler:0), pDb);
+#endif
+  sqlite3_update_hook(db, (pDb->pUpdateHook?DbUpdateHandler:0), pDb);
+  sqlite3_rollback_hook(db, (pDb->pRollbackHook?DbRollbackHandler:0), pDb);
+  sqlite3_wal_hook(db, (pDb->pWalHook?DbWalHandler:0), pDb);
+}
+
 /*
 ** The "sqlite" command below creates a new Tcl command for each
 ** connection it opens to an SQLite database.  This routine is invoked
@@ -1623,11 +1707,12 @@ static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
     "errorcode",          "eval",              "exists",
     "function",           "incrblob",          "interrupt",
     "last_insert_rowid",  "nullvalue",         "onecolumn",
-    "profile",            "progress",          "rekey",
-    "restore",            "rollback_hook",     "status",
-    "timeout",            "total_changes",     "trace",
-    "transaction",        "unlock_notify",     "update_hook",
-    "version",            "wal_hook",          0
+    "preupdate",          "profile",           "progress",
+    "rekey",              "restore",           "rollback_hook",
+    "status",             "timeout",           "total_changes",
+    "trace",              "transaction",       "unlock_notify",
+    "update_hook",        "version",           "wal_hook",
+    0                    
   };
   enum DB_enum {
     DB_AUTHORIZER,        DB_BACKUP,           DB_BUSY,
@@ -1637,11 +1722,11 @@ static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
     DB_ERRORCODE,         DB_EVAL,             DB_EXISTS,
     DB_FUNCTION,          DB_INCRBLOB,         DB_INTERRUPT,
     DB_LAST_INSERT_ROWID, DB_NULLVALUE,        DB_ONECOLUMN,
-    DB_PROFILE,           DB_PROGRESS,         DB_REKEY,
-    DB_RESTORE,           DB_ROLLBACK_HOOK,    DB_STATUS,
-    DB_TIMEOUT,           DB_TOTAL_CHANGES,    DB_TRACE,
-    DB_TRANSACTION,       DB_UNLOCK_NOTIFY,    DB_UPDATE_HOOK,
-    DB_VERSION,           DB_WAL_HOOK
+    DB_PREUPDATE,         DB_PROFILE,          DB_PROGRESS,
+    DB_REKEY,             DB_RESTORE,          DB_ROLLBACK_HOOK,
+    DB_STATUS,            DB_TIMEOUT,          DB_TOTAL_CHANGES,
+    DB_TRACE,             DB_TRANSACTION,      DB_UNLOCK_NOTIFY,
+    DB_UPDATE_HOOK,       DB_VERSION,          DB_WAL_HOOK,
   };
   /* don't leave trailing commas on DB_enum, it confuses the AIX xlc compiler */
 
@@ -2819,6 +2904,90 @@ static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
     break;
   }
 
+  /*
+  **    $db preupdate_hook count
+  **    $db preupdate_hook hook ?SCRIPT?
+  **    $db preupdate_hook new INDEX
+  **    $db preupdate_hook old INDEX
+  */
+  case DB_PREUPDATE: {
+#ifndef SQLITE_ENABLE_PREUPDATE_HOOK
+    Tcl_AppendResult(interp, "preupdate_hook was omitted at compile-time");
+    rc = TCL_ERROR;
+#else
+    static const char *azSub[] = {"count", "depth", "hook", "new", "old", 0};
+    enum DbPreupdateSubCmd {
+      PRE_COUNT, PRE_DEPTH, PRE_HOOK, PRE_NEW, PRE_OLD
+    };
+    int iSub;
+
+    if( objc<3 ){
+      Tcl_WrongNumArgs(interp, 2, objv, "SUB-COMMAND ?ARGS?");
+    }
+    if( Tcl_GetIndexFromObj(interp, objv[2], azSub, "sub-command", 0, &iSub) ){
+      return TCL_ERROR;
+    }
+
+    switch( (enum DbPreupdateSubCmd)iSub ){
+      case PRE_COUNT: {
+        int nCol = sqlite3_preupdate_count(pDb->db);
+        Tcl_SetObjResult(interp, Tcl_NewIntObj(nCol));
+        break;
+      }
+
+      case PRE_HOOK: {
+        if( objc>4 ){
+          Tcl_WrongNumArgs(interp, 2, objv, "hook ?SCRIPT?");
+          return TCL_ERROR;
+        }
+        DbHookCmd(interp, pDb, (objc==4 ? objv[3] : 0), &pDb->pPreUpdateHook);
+        break;
+      }
+
+      case PRE_DEPTH: {
+        Tcl_Obj *pRet;
+        if( objc!=3 ){
+          Tcl_WrongNumArgs(interp, 3, objv, "");
+          return TCL_ERROR;
+        }
+        pRet = Tcl_NewIntObj(sqlite3_preupdate_depth(pDb->db));
+        Tcl_SetObjResult(interp, pRet);
+        break;
+      }
+
+      case PRE_NEW:
+      case PRE_OLD: {
+        int iIdx;
+        sqlite3_value *pValue;
+        if( objc!=4 ){
+          Tcl_WrongNumArgs(interp, 3, objv, "INDEX");
+          return TCL_ERROR;
+        }
+        if( Tcl_GetIntFromObj(interp, objv[3], &iIdx) ){
+          return TCL_ERROR;
+        }
+
+        if( iSub==PRE_OLD ){
+          rc = sqlite3_preupdate_old(pDb->db, iIdx, &pValue);
+        }else{
+          assert( iSub==PRE_NEW );
+          rc = sqlite3_preupdate_new(pDb->db, iIdx, &pValue);
+        }
+
+        if( rc==SQLITE_OK ){
+          Tcl_Obj *pObj;
+          pObj = Tcl_NewStringObj((char*)sqlite3_value_text(pValue), -1);
+          Tcl_SetObjResult(interp, pObj);
+        }else{
+          Tcl_AppendResult(interp, sqlite3_errmsg(pDb->db), 0);
+          return TCL_ERROR;
+        }
+      }
+    }
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+    break;
+  }
+
   /*
   **    $db wal_hook ?script?
   **    $db update_hook ?script?
@@ -2827,42 +2996,19 @@ static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
   case DB_WAL_HOOK: 
   case DB_UPDATE_HOOK: 
   case DB_ROLLBACK_HOOK: {
-
     /* set ppHook to point at pUpdateHook or pRollbackHook, depending on 
     ** whether [$db update_hook] or [$db rollback_hook] was invoked.
     */
     Tcl_Obj **ppHook; 
-    if( choice==DB_UPDATE_HOOK ){
-      ppHook = &pDb->pUpdateHook;
-    }else if( choice==DB_WAL_HOOK ){
-      ppHook = &pDb->pWalHook;
-    }else{
-      ppHook = &pDb->pRollbackHook;
-    }
-
-    if( objc!=2 && objc!=3 ){
+    if( choice==DB_WAL_HOOK ) ppHook = &pDb->pWalHook;
+    if( choice==DB_UPDATE_HOOK ) ppHook = &pDb->pUpdateHook;
+    if( choice==DB_ROLLBACK_HOOK ) ppHook = &pDb->pRollbackHook;
+    if( objc>3 ){
        Tcl_WrongNumArgs(interp, 2, objv, "?SCRIPT?");
        return TCL_ERROR;
     }
-    if( *ppHook ){
-      Tcl_SetObjResult(interp, *ppHook);
-      if( objc==3 ){
-        Tcl_DecrRefCount(*ppHook);
-        *ppHook = 0;
-      }
-    }
-    if( objc==3 ){
-      assert( !(*ppHook) );
-      if( Tcl_GetCharLength(objv[2])>0 ){
-        *ppHook = objv[2];
-        Tcl_IncrRefCount(*ppHook);
-      }
-    }
-
-    sqlite3_update_hook(pDb->db, (pDb->pUpdateHook?DbUpdateHandler:0), pDb);
-    sqlite3_rollback_hook(pDb->db,(pDb->pRollbackHook?DbRollbackHandler:0),pDb);
-    sqlite3_wal_hook(pDb->db,(pDb->pWalHook?DbWalHandler:0),pDb);
 
+    DbHookCmd(interp, pDb, (objc==3 ? objv[2] : 0), ppHook);
     break;
   }
 
@@ -3698,6 +3844,9 @@ static void init_all(Tcl_Interp *interp){
     extern int Sqlitemultiplex_Init(Tcl_Interp*);
     extern int SqliteSuperlock_Init(Tcl_Interp*);
     extern int SqlitetestSyscall_Init(Tcl_Interp*);
+#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+    extern int TestSession_Init(Tcl_Interp*);
+#endif
 
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
     extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
@@ -3740,6 +3889,9 @@ static void init_all(Tcl_Interp *interp){
     Sqlitemultiplex_Init(interp);
     SqliteSuperlock_Init(interp);
     SqlitetestSyscall_Init(interp);
+#if defined(SQLITE_ENABLE_SESSION) && defined(SQLITE_ENABLE_PREUPDATE_HOOK)
+    TestSession_Init(interp);
+#endif
 
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
     Sqlitetestfts3_Init(interp);

src/test_config.c

@@ -123,6 +123,12 @@ static void set_options(Tcl_Interp *interp){
   Tcl_SetVar2(interp, "sqlite_options", "mem5", "0", TCL_GLOBAL_ONLY);
 #endif
 
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  Tcl_SetVar2(interp, "sqlite_options", "preupdate", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "preupdate", "0", TCL_GLOBAL_ONLY);
+#endif
+
 #ifdef SQLITE_MUTEX_OMIT
   Tcl_SetVar2(interp, "sqlite_options", "mutex", "0", TCL_GLOBAL_ONLY);
 #else
@@ -465,6 +471,12 @@ Tcl_SetVar2(interp, "sqlite_options", "mergesort", "1", TCL_GLOBAL_ONLY);
   Tcl_SetVar2(interp, "sqlite_options", "schema_version", "1", TCL_GLOBAL_ONLY);
 #endif
 
+#ifdef SQLITE_ENABLE_SESSION
+  Tcl_SetVar2(interp, "sqlite_options", "session", "1", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "session", "0", TCL_GLOBAL_ONLY);
+#endif
+
 #ifdef SQLITE_ENABLE_STAT4
   Tcl_SetVar2(interp, "sqlite_options", "stat4", "1", TCL_GLOBAL_ONLY);
 #else

src/test_rtree.c

@@ -50,11 +50,7 @@ static void circle_del(void *p){
 static int circle_geom(
   sqlite3_rtree_geometry *p,
   int nCoord, 
-#ifdef SQLITE_RTREE_INT_ONLY
-  sqlite3_int64 *aCoord,
-#else
-  double *aCoord, 
-#endif
+  sqlite3_rtree_dbl *aCoord,
   int *pRes
 ){
   int i;                          /* Iterator variable */
@@ -154,6 +150,113 @@ static int circle_geom(
   return SQLITE_OK;
 }
 
+/*
+** Implementation of "circle" r-tree geometry callback using the 
+** 2nd-generation interface that allows scoring.
+*/
+static int circle_query_func(sqlite3_rtree_query_info *p){
+  int i;                          /* Iterator variable */
+  Circle *pCircle;                /* Structure defining circular region */
+  double xmin, xmax;              /* X dimensions of box being tested */
+  double ymin, ymax;              /* X dimensions of box being tested */
+  int nWithin = 0;                /* Number of corners inside the circle */
+
+  if( p->pUser==0 ){
+    /* If pUser is still 0, then the parameter values have not been tested
+    ** for correctness or stored into a Circle structure yet. Do this now. */
+
+    /* This geometry callback is for use with a 2-dimensional r-tree table.
+    ** Return an error if the table does not have exactly 2 dimensions. */
+    if( p->nCoord!=4 ) return SQLITE_ERROR;
+
+    /* Test that the correct number of parameters (3) have been supplied,
+    ** and that the parameters are in range (that the radius of the circle 
+    ** radius is greater than zero). */
+    if( p->nParam!=3 || p->aParam[2]<0.0 ) return SQLITE_ERROR;
+
+    /* Allocate a structure to cache parameter data in. Return SQLITE_NOMEM
+    ** if the allocation fails. */
+    pCircle = (Circle *)(p->pUser = sqlite3_malloc(sizeof(Circle)));
+    if( !pCircle ) return SQLITE_NOMEM;
+    p->xDelUser = circle_del;
+
+    /* Record the center and radius of the circular region. One way that
+    ** tested bounding boxes that intersect the circular region are detected
+    ** is by testing if each corner of the bounding box lies within radius
+    ** units of the center of the circle. */
+    pCircle->centerx = p->aParam[0];
+    pCircle->centery = p->aParam[1];
+    pCircle->radius = p->aParam[2];
+
+    /* Define two bounding box regions. The first, aBox[0], extends to
+    ** infinity in the X dimension. It covers the same range of the Y dimension
+    ** as the circular region. The second, aBox[1], extends to infinity in
+    ** the Y dimension and is constrained to the range of the circle in the
+    ** X dimension.
+    **
+    ** Then imagine each box is split in half along its short axis by a line
+    ** that intersects the center of the circular region. A bounding box
+    ** being tested can be said to intersect the circular region if it contains
+    ** points from each half of either of the two infinite bounding boxes.
+    */
+    pCircle->aBox[0].xmin = pCircle->centerx;
+    pCircle->aBox[0].xmax = pCircle->centerx;
+    pCircle->aBox[0].ymin = pCircle->centery + pCircle->radius;
+    pCircle->aBox[0].ymax = pCircle->centery - pCircle->radius;
+    pCircle->aBox[1].xmin = pCircle->centerx + pCircle->radius;
+    pCircle->aBox[1].xmax = pCircle->centerx - pCircle->radius;
+    pCircle->aBox[1].ymin = pCircle->centery;
+    pCircle->aBox[1].ymax = pCircle->centery;
+  }
+
+  pCircle = (Circle *)p->pUser;
+  xmin = p->aCoord[0];
+  xmax = p->aCoord[1];
+  ymin = p->aCoord[2];
+  ymax = p->aCoord[3];
+
+  /* Check if any of the 4 corners of the bounding-box being tested lie 
+  ** inside the circular region. If they do, then the bounding-box does
+  ** intersect the region of interest. Set the output variable to true and
+  ** return SQLITE_OK in this case. */
+  for(i=0; i<4; i++){
+    double x = (i&0x01) ? xmax : xmin;
+    double y = (i&0x02) ? ymax : ymin;
+    double d2;
+    
+    d2  = (x-pCircle->centerx)*(x-pCircle->centerx);
+    d2 += (y-pCircle->centery)*(y-pCircle->centery);
+    if( d2<(pCircle->radius*pCircle->radius) ) nWithin++;
+  }
+
+  /* Check if the bounding box covers any other part of the circular region.
+  ** See comments above for a description of how this test works. If it does
+  ** cover part of the circular region, set the output variable to true
+  ** and return SQLITE_OK. */
+  if( nWithin==0 ){
+    for(i=0; i<2; i++){
+      if( xmin<=pCircle->aBox[i].xmin 
+       && xmax>=pCircle->aBox[i].xmax 
+       && ymin<=pCircle->aBox[i].ymin 
+       && ymax>=pCircle->aBox[i].ymax 
+      ){
+        nWithin = 1;
+        break;
+      }
+    }
+  }
+
+  p->rScore = p->iLevel;
+  if( nWithin==0 ){
+    p->eWithin = NOT_WITHIN;
+  }else if( nWithin>=4 ){
+    p->eWithin = FULLY_WITHIN;
+  }else{
+    p->eWithin = PARTLY_WITHIN;
+  }
+  return SQLITE_OK;
+}
+
 /* END of implementation of "circle" geometry callback.
 **************************************************************************
 *************************************************************************/
@@ -194,11 +297,7 @@ static int gHere = 42;
 static int cube_geom(
   sqlite3_rtree_geometry *p,
   int nCoord,
-#ifdef SQLITE_RTREE_INT_ONLY
-  sqlite3_int64 *aCoord, 
-#else
-  double *aCoord, 
-#endif
+  sqlite3_rtree_dbl *aCoord,
   int *piRes
 ){
   Cube *pCube = (Cube *)p->pUser;
@@ -293,6 +392,10 @@ static int register_circle_geom(
   }
   if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
   rc = sqlite3_rtree_geometry_callback(db, "circle", circle_geom, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_rtree_query_callback(db, "Qcircle",
+                                      circle_query_func, 0, 0);
+  }
   Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
 #endif
   return TCL_OK;

src/update.c

@@ -583,10 +583,23 @@ void sqlite3Update(
       VdbeCoverageNeverTaken(v);
     }
     sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx);
-  
-    /* If changing the record number, delete the old record.  */
-    if( hasFK || chngKey || pPk!=0 ){
-      sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0);
+
+    /* If changing the rowid value, or if there are foreign key constraints
+    ** to process, delete the old record. Otherwise, add a noop OP_Delete
+    ** to invoke the pre-update hook.
+    **
+    ** That (regNew==regnewRowid+1) is true is also important for the 
+    ** pre-update hook. If the caller invokes preupdate_new(), the returned
+    ** value is copied from memory cell (regNewRowid+1+iCol), where iCol
+    ** is the column index supplied by the user.
+    */
+    assert( regNew==regNewRowid+1 );
+    sqlite3VdbeAddOp3(v, OP_Delete, iDataCur,
+        OPFLAG_ISUPDATE | ((hasFK || chngKey || pPk!=0) ? 0 : OPFLAG_ISNOOP),
+        regNewRowid
+    );
+    if( !pParse->nested ){
+      sqlite3VdbeChangeP4(v, -1, (char*)pTab, P4_TABLE);
     }
     if( bReplace || chngKey ){
       sqlite3VdbeJumpHere(v, j1);

src/vdbe.c

@@ -86,6 +86,16 @@ static void updateMaxBlobsize(Mem *p){
 }
 #endif
 
+/*
+** This macro evaluates to true if either the update hook or the preupdate
+** hook are enabled for database connect DB.
+*/
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+# define HAS_UPDATE_HOOK(DB)   ((DB)->xPreUpdateCallback||(DB)->xUpdateCallback)
+#else
+# define HAS_UPDATE_HOOK(DB)  ((DB)->xUpdateCallback)
+#endif
+
 /*
 ** The next global variable is incremented each time the OP_Found opcode
 ** is executed. This is used to test whether or not the foreign key
@@ -2811,7 +2821,7 @@ case OP_Savepoint: {
         }else{
           db->nSavepoint++;
         }
-    
+
         /* Link the new savepoint into the database handle's list. */
         pNew->pNext = db->pSavepoint;
         db->pSavepoint = pNew;
@@ -4035,9 +4045,9 @@ case OP_NewRowid: {           /* out2-prerelease */
 ** is part of an INSERT operation.  The difference is only important to
 ** the update hook.
 **
-** Parameter P4 may point to a string containing the table-name, or
-** may be NULL. If it is not NULL, then the update-hook 
-** (sqlite3.xUpdateCallback) is invoked following a successful insert.
+** Parameter P4 may point to a Table structure, or may be NULL. If it is 
+** not NULL, then the update-hook (sqlite3.xUpdateCallback) is invoked 
+** following a successful insert.
 **
 ** (WARNING/TODO: If P1 is a pseudo-cursor and P2 is dynamically
 ** allocated, then ownership of P2 is transferred to the pseudo-cursor
@@ -4063,8 +4073,8 @@ case OP_InsertInt: {
   int nZero;        /* Number of zero-bytes to append */
   int seekResult;   /* Result of prior seek or 0 if no USESEEKRESULT flag */
   const char *zDb;  /* database name - used by the update hook */
-  const char *zTbl; /* Table name - used by the opdate hook */
-  int op;           /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
+  Table *pTab;      /* Table structure - used by update and pre-update hooks */
+  int op = 0;       /* Opcode for update hook: SQLITE_UPDATE or SQLITE_INSERT */
 
   pData = &aMem[pOp->p2];
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
@@ -4074,6 +4084,7 @@ case OP_InsertInt: {
   assert( pC->pCursor!=0 );
   assert( pC->pseudoTableReg==0 );
   assert( pC->isTable );
+  assert( pOp->p4type==P4_TABLE || pOp->p4type>=P4_STATIC );
   REGISTER_TRACE(pOp->p2, pData);
 
   if( pOp->opcode==OP_Insert ){
@@ -4087,6 +4098,25 @@ case OP_InsertInt: {
     iKey = pOp->p3;
   }
 
+  if( pOp->p4type==P4_TABLE && HAS_UPDATE_HOOK(db) ){
+    assert( pC->isTable );
+    assert( pC->iDb>=0 );
+    zDb = db->aDb[pC->iDb].zName;
+    pTab = pOp->p4.pTab;
+    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
+  }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  /* Invoke the pre-update hook, if any */
+  if( db->xPreUpdateCallback 
+   && pOp->p4type==P4_TABLE
+   && (!(pOp->p5 & OPFLAG_ISUPDATE) || pC->rowidIsValid==0)
+   && HasRowid(pTab)
+  ){
+    sqlite3VdbePreUpdateHook(p, pC, SQLITE_INSERT, zDb, pTab, iKey, pOp->p2);
+  }
+#endif
+
   if( pOp->p5 & OPFLAG_NCHANGE ) p->nChange++;
   if( pOp->p5 & OPFLAG_LASTROWID ) db->lastRowid = lastRowid = iKey;
   if( pData->flags & MEM_Null ){
@@ -4110,18 +4140,13 @@ case OP_InsertInt: {
   pC->cacheStatus = CACHE_STALE;
 
   /* Invoke the update-hook if required. */
-  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z ){
-    zDb = db->aDb[pC->iDb].zName;
-    zTbl = pOp->p4.z;
-    op = ((pOp->p5 & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_INSERT);
-    assert( pC->isTable );
-    db->xUpdateCallback(db->pUpdateArg, op, zDb, zTbl, iKey);
-    assert( pC->iDb>=0 );
+  if( rc==SQLITE_OK && db->xUpdateCallback && op && HasRowid(pTab) ){
+    db->xUpdateCallback(db->pUpdateArg, op, zDb, pTab->zName, iKey);
   }
   break;
 }
 
-/* Opcode: Delete P1 P2 * P4 *
+/* Opcode: Delete P1 P2 P3 P4 *
 **
 ** Delete the record at which the P1 cursor is currently pointing.
 **
@@ -4136,15 +4161,25 @@ case OP_InsertInt: {
 ** P1 must not be pseudo-table.  It has to be a real table with
 ** multiple rows.
 **
-** If P4 is not NULL, then it is the name of the table that P1 is
-** pointing to.  The update hook will be invoked, if it exists.
-** If P4 is not NULL then the P1 cursor must have been positioned
-** using OP_NotFound prior to invoking this opcode.
+** If P4 is not NULL then it points to a Table struture. In this case either 
+** the update or pre-update hook, or both, may be invoked. The P1 cursor must
+** have been positioned using OP_NotFound prior to invoking this opcode in 
+** this case. Specifically, if one is configured, the pre-update hook is 
+** invoked if P4 is not NULL. The update-hook is invoked if one is configured, 
+** P4 is not NULL, and the OPFLAG_NCHANGE flag is set in P2.
+**
+** If the OPFLAG_ISUPDATE flag is set in P2, then P3 contains the address
+** of the memory cell that contains the value that the rowid of the row will
+** be set to by the update.
 */
 case OP_Delete: {
   i64 iKey;
   VdbeCursor *pC;
+  const char *zDb;
+  Table *pTab;
+  int opflags;
 
+  opflags = pOp->p2;
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
@@ -4162,16 +4197,42 @@ case OP_Delete: {
   rc = sqlite3VdbeCursorMoveto(pC);
   if( NEVER(rc!=SQLITE_OK) ) goto abort_due_to_error;
 
+  /* If the update-hook or pre-update-hook will be invoked, set iKey to 
+  ** the rowid of the row being deleted. Set zDb and zTab as well.
+  */
+  if( pOp->p4.z && HAS_UPDATE_HOOK(db) ){
+    assert( pC->iDb>=0 );
+    assert( pC->rowidIsValid || !HasRowid(pOp->p4.pTab) );
+    iKey = pC->lastRowid;
+    zDb = db->aDb[pC->iDb].zName;
+    pTab = pOp->p4.pTab;
+ }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+  /* Invoke the pre-update-hook if required. */
+  if( db->xPreUpdateCallback && pOp->p4.z && HasRowid(pTab) ){
+    assert( !(opflags & OPFLAG_ISUPDATE) || (aMem[pOp->p3].flags & MEM_Int) );
+    sqlite3VdbePreUpdateHook(p, pC,
+        (opflags & OPFLAG_ISUPDATE) ? SQLITE_UPDATE : SQLITE_DELETE, 
+        zDb, pTab, iKey,
+        pOp->p3
+    );
+  }
+#endif
+
+  if( opflags & OPFLAG_ISNOOP ) break;
+
   rc = sqlite3BtreeDelete(pC->pCursor);
   pC->cacheStatus = CACHE_STALE;
 
-  /* Invoke the update-hook if required. */
-  if( rc==SQLITE_OK && db->xUpdateCallback && pOp->p4.z && pC->isTable ){
-    db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE,
-                        db->aDb[pC->iDb].zName, pOp->p4.z, iKey);
-    assert( pC->iDb>=0 );
+  /* Update the change-counter and invoke the update-hook if required. */
+  if( opflags & OPFLAG_NCHANGE ){
+    p->nChange++;
+    assert( pOp->p4.z );
+    if( rc==SQLITE_OK && db->xUpdateCallback && HasRowid(pTab) ){
+      db->xUpdateCallback(db->pUpdateArg, SQLITE_DELETE, zDb, pTab->zName,iKey);
+    }
   }
-  if( pOp->p2 & OPFLAG_NCHANGE ) p->nChange++;
   break;
 }
 /* Opcode: ResetCount * * * * *

src/vdbe.h

@@ -59,6 +59,7 @@ struct VdbeOp {
     KeyInfo *pKeyInfo;     /* Used when p4type is P4_KEYINFO */
     int *ai;               /* Used when p4type is P4_INTARRAY */
     SubProgram *pProgram;  /* Used when p4type is P4_SUBPROGRAM */
+    Table *pTab;           /* Used when p4type is P4_TABLE */
     int (*xAdvance)(BtCursor *, int *);
   } p4;
 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
@@ -119,6 +120,7 @@ typedef struct VdbeOpList VdbeOpList;
 #define P4_INTARRAY (-15) /* P4 is a vector of 32-bit integers */
 #define P4_SUBPROGRAM  (-18) /* P4 is a pointer to a SubProgram structure */
 #define P4_ADVANCE  (-19) /* P4 is a pointer to BtreeNext() or BtreePrev() */
+#define P4_TABLE    (-20) /* P4 is a pointer to a Table structure */
 
 /* Error message codes for OP_Halt */
 #define P5_ConstraintNotNull 1

src/vdbeInt.h

@@ -376,6 +376,25 @@ struct Vdbe {
 #define VDBE_MAGIC_HALT     0x519c2973    /* VDBE has completed execution */
 #define VDBE_MAGIC_DEAD     0xb606c3c8    /* The VDBE has been deallocated */
 
+/*
+** Structure used to store the context required by the 
+** sqlite3_preupdate_*() API functions.
+*/
+struct PreUpdate {
+  Vdbe *v;
+  VdbeCursor *pCsr;               /* Cursor to read old values from */
+  int op;                         /* One of SQLITE_INSERT, UPDATE, DELETE */
+  u8 *aRecord;                    /* old.* database record */
+  KeyInfo keyinfo;
+  UnpackedRecord *pUnpacked;      /* Unpacked version of aRecord[] */
+  UnpackedRecord *pNewUnpacked;   /* Unpacked version of new.* record */
+  int iNewReg;                    /* Register for new.* values */
+  i64 iKey1;                      /* First key value passed to hook */
+  i64 iKey2;                      /* Second key value passed to hook */
+  int iPKey;                      /* If not negative index of IPK column */
+  Mem *aNew;                      /* Array of new.* values */
+};
+
 /*
 ** Function prototypes
 */
@@ -435,6 +454,8 @@ int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
 int sqlite3VdbeCloseStatement(Vdbe *, int);
 void sqlite3VdbeFrameDelete(VdbeFrame*);
 int sqlite3VdbeFrameRestore(VdbeFrame *);
+void sqlite3VdbePreUpdateHook(
+    Vdbe *, VdbeCursor *, int, const char*, Table *, i64, int);
 int sqlite3VdbeTransferError(Vdbe *p);
 
 int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);

src/vdbeapi.c

@@ -1353,3 +1353,184 @@ int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
   if( resetFlag ) pVdbe->aCounter[op] = 0;
   return (int)v;
 }
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** Allocate and populate an UnpackedRecord structure based on the serialized
+** record in nKey/pKey. Return a pointer to the new UnpackedRecord structure
+** if successful, or a NULL pointer if an OOM error is encountered.
+*/
+static UnpackedRecord *vdbeUnpackRecord(
+  KeyInfo *pKeyInfo, 
+  int nKey, 
+  const void *pKey
+){
+  char *dummy;                    /* Dummy argument for AllocUnpackedRecord() */
+  UnpackedRecord *pRet;           /* Return value */
+
+  pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo, 0, 0, &dummy);
+  if( pRet ){
+    memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nField+1));
+    sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
+  }
+  return pRet;
+}
+
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or deleted.
+*/
+int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  int rc = SQLITE_OK;
+
+  /* Test that this call is being made from within an SQLITE_DELETE or
+  ** SQLITE_UPDATE pre-update callback, and that iIdx is within range. */
+  if( !p || p->op==SQLITE_INSERT ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_old_out;
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_old_out;
+  }
+
+  /* If the old.* record has not yet been loaded into memory, do so now. */
+  if( p->pUnpacked==0 ){
+    u32 nRec;
+    u8 *aRec;
+
+    rc = sqlite3BtreeDataSize(p->pCsr->pCursor, &nRec);
+    if( rc!=SQLITE_OK ) goto preupdate_old_out;
+    aRec = sqlite3DbMallocRaw(db, nRec);
+    if( !aRec ) goto preupdate_old_out;
+    rc = sqlite3BtreeData(p->pCsr->pCursor, 0, nRec, aRec);
+    if( rc==SQLITE_OK ){
+      p->pUnpacked = vdbeUnpackRecord(&p->keyinfo, nRec, aRec);
+      if( !p->pUnpacked ) rc = SQLITE_NOMEM;
+    }
+    if( rc!=SQLITE_OK ){
+      sqlite3DbFree(db, aRec);
+      goto preupdate_old_out;
+    }
+    p->aRecord = aRec;
+  }
+
+  if( iIdx>=p->pUnpacked->nField ){
+    *ppValue = (sqlite3_value *)columnNullValue();
+  }else{
+    *ppValue = &p->pUnpacked->aMem[iIdx];
+    if( iIdx==p->iPKey ){
+      sqlite3VdbeMemSetInt64(*ppValue, p->iKey1);
+    }
+  }
+
+ preupdate_old_out:
+  sqlite3Error(db, rc, 0);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** the number of columns in the row being updated, deleted or inserted.
+*/
+int sqlite3_preupdate_count(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->keyinfo.nField : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is designed to be called from within a pre-update callback
+** only. It returns zero if the change that caused the callback was made
+** immediately by a user SQL statement. Or, if the change was made by a
+** trigger program, it returns the number of trigger programs currently
+** on the stack (1 for a top-level trigger, 2 for a trigger fired by a 
+** top-level trigger etc.).
+**
+** For the purposes of the previous paragraph, a foreign key CASCADE, SET NULL
+** or SET DEFAULT action is considered a trigger.
+*/
+int sqlite3_preupdate_depth(sqlite3 *db){
+  PreUpdate *p = db->pPreUpdate;
+  return (p ? p->v->nFrame : 0);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+/*
+** This function is called from within a pre-update callback to retrieve
+** a field of the row currently being updated or inserted.
+*/
+int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
+  PreUpdate *p = db->pPreUpdate;
+  int rc = SQLITE_OK;
+  Mem *pMem;
+
+  if( !p || p->op==SQLITE_DELETE ){
+    rc = SQLITE_MISUSE_BKPT;
+    goto preupdate_new_out;
+  }
+  if( iIdx>=p->pCsr->nField || iIdx<0 ){
+    rc = SQLITE_RANGE;
+    goto preupdate_new_out;
+  }
+
+  if( p->op==SQLITE_INSERT ){
+    /* For an INSERT, memory cell p->iNewReg contains the serialized record
+    ** that is being inserted. Deserialize it. */
+    UnpackedRecord *pUnpack = p->pNewUnpacked;
+    if( !pUnpack ){
+      Mem *pData = &p->v->aMem[p->iNewReg];
+      rc = sqlite3VdbeMemExpandBlob(pData);
+      if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      pUnpack = vdbeUnpackRecord(&p->keyinfo, pData->n, pData->z);
+      if( !pUnpack ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+      p->pNewUnpacked = pUnpack;
+    }
+    if( iIdx>=pUnpack->nField ){
+      pMem = (sqlite3_value *)columnNullValue();
+    }else{
+      pMem = &pUnpack->aMem[iIdx];
+      if( iIdx==p->iPKey ){
+        sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+      }
+    }
+  }else{
+    /* For an UPDATE, memory cell (p->iNewReg+1+iIdx) contains the required
+    ** value. Make a copy of the cell contents and return a pointer to it.
+    ** It is not safe to return a pointer to the memory cell itself as the
+    ** caller may modify the value text encoding.
+    */
+    assert( p->op==SQLITE_UPDATE );
+    if( !p->aNew ){
+      p->aNew = (Mem *)sqlite3DbMallocZero(db, sizeof(Mem) * p->pCsr->nField);
+      if( !p->aNew ){
+        rc = SQLITE_NOMEM;
+        goto preupdate_new_out;
+      }
+    }
+    assert( iIdx>=0 && iIdx<p->pCsr->nField );
+    pMem = &p->aNew[iIdx];
+    if( pMem->flags==0 ){
+      if( iIdx==p->iPKey ){
+        sqlite3VdbeMemSetInt64(pMem, p->iKey2);
+      }else{
+        rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
+        if( rc!=SQLITE_OK ) goto preupdate_new_out;
+      }
+    }
+  }
+  *ppValue = pMem;
+
+ preupdate_new_out:
+  sqlite3Error(db, rc, 0);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

src/vdbeaux.c

@@ -68,6 +68,7 @@ const char *sqlite3_sql(sqlite3_stmt *pStmt){
 void sqlite3VdbeSwap(Vdbe *pA, Vdbe *pB){
   Vdbe tmp, *pTmp;
   char *zTmp;
+  assert( pA->db==pB->db );
   tmp = *pA;
   *pA = *pB;
   *pB = tmp;
@@ -3121,6 +3122,7 @@ void sqlite3VdbeRecordUnpack(
     pMem->db = pKeyInfo->db;
     /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
     pMem->zMalloc = 0;
+    pMem->z = 0;
     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
     pMem++;
     u++;
@@ -4012,3 +4014,85 @@ void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
   pVtab->zErrMsg = 0;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+
+/*
+** If the second argument is not NULL, release any allocations associated 
+** with the memory cells in the p->aMem[] array. Also free the UnpackedRecord
+** structure itself, using sqlite3DbFree().
+**
+** This function is used to free UnpackedRecord structures allocated by
+** the vdbeUnpackRecord() function found in vdbeapi.c.
+*/
+static void vdbeFreeUnpacked(sqlite3 *db, UnpackedRecord *p){
+  if( p ){
+    int i;
+    for(i=0; i<p->nField; i++){
+      Mem *pMem = &p->aMem[i];
+      if( pMem->zMalloc ) sqlite3VdbeMemRelease(pMem);
+    }
+    sqlite3DbFree(db, p);
+  }
+}
+
+/*
+** Invoke the pre-update hook. If this is an UPDATE or DELETE pre-update call,
+** then cursor passed as the second argument should point to the row about
+** to be update or deleted. If the application calls sqlite3_preupdate_old(),
+** the required value will be read from the row the cursor points to.
+*/
+void sqlite3VdbePreUpdateHook(
+  Vdbe *v,                        /* Vdbe pre-update hook is invoked by */
+  VdbeCursor *pCsr,               /* Cursor to grab old.* values from */
+  int op,                         /* SQLITE_INSERT, UPDATE or DELETE */
+  const char *zDb,                /* Database name */
+  Table *pTab,                    /* Modified table */
+  i64 iKey1,                      /* Initial key value */
+  int iReg                        /* Register for new.* record */
+){
+  sqlite3 *db = v->db;
+  i64 iKey2;
+  PreUpdate preupdate;
+  const char *zTbl = pTab->zName;
+  static const u8 fakeSortOrder = 0;
+
+  assert( db->pPreUpdate==0 );
+  memset(&preupdate, 0, sizeof(PreUpdate));
+  if( op==SQLITE_UPDATE ){
+    iKey2 = v->aMem[iReg].u.i;
+  }else{
+    iKey2 = iKey1;
+  }
+
+  assert( pCsr->nField==pTab->nCol 
+       || (pCsr->nField==pTab->nCol+1 && op==SQLITE_DELETE && iReg==-1)
+  );
+
+  preupdate.v = v;
+  preupdate.pCsr = pCsr;
+  preupdate.op = op;
+  preupdate.iNewReg = iReg;
+  preupdate.keyinfo.db = db;
+  preupdate.keyinfo.enc = ENC(db);
+  preupdate.keyinfo.nField = pTab->nCol;
+  preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;
+  preupdate.iKey1 = iKey1;
+  preupdate.iKey2 = iKey2;
+  preupdate.iPKey = pTab->iPKey;
+
+  db->pPreUpdate = &preupdate;
+  db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
+  db->pPreUpdate = 0;
+  sqlite3DbFree(db, preupdate.aRecord);
+  vdbeFreeUnpacked(db, preupdate.pUnpacked);
+  vdbeFreeUnpacked(db, preupdate.pNewUnpacked);
+  if( preupdate.aNew ){
+    int i;
+    for(i=0; i<pCsr->nField; i++){
+      sqlite3VdbeMemRelease(&preupdate.aNew[i]);
+    }
+    sqlite3DbFree(db, preupdate.aNew);
+  }
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

src/vdbeblob.c

@@ -30,6 +30,8 @@ struct Incrblob {
   BtCursor *pCsr;         /* Cursor pointing at blob row */
   sqlite3_stmt *pStmt;    /* Statement holding cursor open */
   sqlite3 *db;            /* The associated database */
+  char *zDb;              /* Database name */
+  Table *pTab;            /* Table object */
 };
 
 
@@ -197,6 +199,8 @@ int sqlite3_blob_open(
       sqlite3BtreeLeaveAll(db);
       goto blob_open_out;
     }
+    pBlob->pTab = pTab;
+    pBlob->zDb = db->aDb[sqlite3SchemaToIndex(db, pTab->pSchema)].zName;
 
     /* Now search pTab for the exact column. */
     for(iCol=0; iCol<pTab->nCol; iCol++) {
@@ -385,6 +389,30 @@ static int blobReadWrite(
     */
     assert( db == v->db );
     sqlite3BtreeEnterCursor(p->pCsr);
+
+#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
+    if( xCall==sqlite3BtreePutData && db->xPreUpdateCallback ){
+      /* If a pre-update hook is registered and this is a write cursor, 
+      ** invoke it here. 
+      ** 
+      ** TODO: The preupdate-hook is passed SQLITE_DELETE, even though this
+      ** operation should really be an SQLITE_UPDATE. This is probably
+      ** incorrect, but is convenient because at this point the new.* values 
+      ** are not easily obtainable. And for the sessions module, an 
+      ** SQLITE_UPDATE where the PK columns do not change is handled in the 
+      ** same way as an SQLITE_DELETE (the SQLITE_DELETE code is actually
+      ** slightly more efficient). Since you cannot write to a PK column
+      ** using the incremental-blob API, this works. For the sessions module
+      ** anyhow.
+      */
+      sqlite3_int64 iKey;
+      sqlite3BtreeKeySize(p->pCsr, &iKey);
+      sqlite3VdbePreUpdateHook(
+          v, v->apCsr[0], SQLITE_DELETE, p->zDb, p->pTab, iKey, -1
+      );
+    }
+#endif
+
     rc = xCall(p->pCsr, iOffset+p->iOffset, n, z);
     sqlite3BtreeLeaveCursor(p->pCsr);
     if( rc==SQLITE_ABORT ){

test/fkey6.test

@@ -1,4 +1,4 @@
-# 2013-07-11
+# 2012 December 17
 #
 # The author disclaims copyright to this source code.  In place of
 # a legal notice, here is a blessing:

test/hook.test

@@ -21,6 +21,7 @@
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
+set ::testprefix hook
 
 do_test hook-1.2 {
   db commit_hook
@@ -196,6 +197,7 @@ do_test hook-4.1.2 {
 # EVIDENCE-OF: R-33257-44249 The update hook is not invoked when WITHOUT
 # ROWID tables are modified.
 #
+breakpoint
 do_test hook-4.1.2w {
   set ::update_hook {}
   execsql {
@@ -438,4 +440,411 @@ do_test hook-6.2 {
 } {COMMIT ROLLBACK}
 unset ::hooks
 
+#----------------------------------------------------------------------------
+# The following tests - hook-7.* - test the pre-update hook.
+#
+ifcapable !preupdate {
+  finish_test
+  return
+}
+#
+# 7.1.1 - INSERT statement.
+# 7.1.2 - INSERT INTO ... SELECT statement.
+# 7.1.3 - REPLACE INTO ... (rowid conflict)
+# 7.1.4 - REPLACE INTO ... (other index conflicts)
+# 7.1.5 - REPLACE INTO ... (both rowid and other index conflicts)
+#
+# 7.2.1 - DELETE statement.
+# 7.2.2 - DELETE statement that uses the truncate optimization.
+#
+# 7.3.1 - UPDATE statement.
+# 7.3.2 - UPDATE statement that modifies the rowid.
+# 7.3.3 - UPDATE OR REPLACE ... (rowid conflict).
+# 7.3.4 - UPDATE OR REPLACE ... (other index conflicts)
+# 7.3.4 - UPDATE OR REPLACE ... (both rowid and other index conflicts)
+#
+# 7.4.1 - Test that the pre-update-hook is invoked only once if a row being
+#         deleted is removed by a BEFORE trigger.
+#
+# 7.4.2 - Test that the pre-update-hook is invoked if a BEFORE trigger 
+#         removes a row being updated. In this case the update hook should
+#         be invoked with SQLITE_INSERT as the opcode when inserting the
+#         new version of the row.
+#         
+# TODO: Short records (those created before a column is added to a table 
+#       using ALTER TABLE)
+#
+
+proc do_preupdate_test {tn sql x} {
+  set X [list]
+  foreach elem $x {lappend X $elem}
+  uplevel do_test $tn [list "
+    set ::preupdate \[list\]
+    execsql { $sql }
+    set ::preupdate
+  "] [list $X]
+}
+
+proc preupdate_hook {args} {
+  set type [lindex $args 0]
+  eval lappend ::preupdate $args
+  if {$type != "INSERT"} {
+    for {set i 0} {$i < [db preupdate count]} {incr i} {
+      lappend ::preupdate [db preupdate old $i]
+    }
+  }
+  if {$type != "DELETE"} {
+    for {set i 0} {$i < [db preupdate count]} {incr i} {
+      set rc [catch { db preupdate new $i } v]
+      lappend ::preupdate $v
+    }
+  }
+}
+
+db close
+forcedelete test.db
+sqlite3 db test.db
+db preupdate hook preupdate_hook
+
+# Set up a schema to use for tests 7.1.* to 7.3.*.
+do_execsql_test 7.0 { 
+  CREATE TABLE t1(a, b); 
+  CREATE TABLE t2(x, y); 
+  CREATE TABLE t3(i, j, UNIQUE(i));
+
+  INSERT INTO t2 VALUES('a', 'b');
+  INSERT INTO t2 VALUES('c', 'd');
+
+  INSERT INTO t3 VALUES(4, 16);
+  INSERT INTO t3 VALUES(5, 25);
+  INSERT INTO t3 VALUES(6, 36);
+} 
+
+do_preupdate_test 7.1.1 {
+  INSERT INTO t1 VALUES('x', 'y')
+} {INSERT main t1 1 1  x y}
+
+# 7.1.2.1 does not use the xfer optimization. 7.1.2.2 does.
+do_preupdate_test 7.1.2.1 {
+  INSERT INTO t1 SELECT y, x FROM t2;
+} {INSERT main t1 2 2 b a   INSERT main t1 3 3 d c}
+do_preupdate_test 7.1.2.2 {
+  INSERT INTO t1 SELECT * FROM t2;
+} {INSERT main t1 4 4 a b   INSERT main t1 5 5 c d}
+
+do_preupdate_test 7.1.3 {
+  REPLACE INTO t1(rowid, a, b) VALUES(1, 1, 1);
+} {
+  DELETE main t1 1 1   x y
+  INSERT main t1 1 1   1 1
+}
+
+do_preupdate_test 7.1.4 {
+  REPLACE INTO t3 VALUES(4, NULL);
+} {
+  DELETE main t3 1 1   4 16
+  INSERT main t3 4 4   4 {}
+}
+
+do_preupdate_test 7.1.5 {
+  REPLACE INTO t3(rowid, i, j) VALUES(2, 6, NULL);
+} {
+  DELETE main t3 2 2  5 25
+  DELETE main t3 3 3  6 36
+  INSERT main t3 2 2  6 {}
+}
+
+do_execsql_test 7.2.0 { SELECT rowid FROM t1 } {1 2 3 4 5}
+
+do_preupdate_test 7.2.1 {
+  DELETE FROM t1 WHERE rowid = 3
+} {
+  DELETE main t1 3 3  d c
+}
+do_preupdate_test 7.2.2 {
+  DELETE FROM t1
+} {
+  DELETE main t1 1 1   1 1
+  DELETE main t1 2 2   b a
+  DELETE main t1 4 4   a b
+  DELETE main t1 5 5   c d
+}
+
+do_execsql_test 7.3.0 { 
+  DELETE FROM t1;
+  DELETE FROM t2;
+  DELETE FROM t3;
+
+  INSERT INTO t2 VALUES('a', 'b');
+  INSERT INTO t2 VALUES('c', 'd');
+
+  INSERT INTO t3 VALUES(4, 16);
+  INSERT INTO t3 VALUES(5, 25);
+  INSERT INTO t3 VALUES(6, 36);
+}
+
+do_preupdate_test 7.3.1 {
+  UPDATE t2 SET y = y||y;
+} {
+  UPDATE main t2 1 1   a b  a bb
+  UPDATE main t2 2 2   c d  c dd
+}
+
+do_preupdate_test 7.3.2 {
+  UPDATE t2 SET rowid = rowid-1;
+} {
+  UPDATE main t2 1 0   a bb  a bb
+  UPDATE main t2 2 1   c dd  c dd
+}
+
+do_preupdate_test 7.3.3 {
+  UPDATE OR REPLACE t2 SET rowid = 1 WHERE x = 'a'
+} {
+  DELETE main t2 1 1   c dd
+  UPDATE main t2 0 1   a bb  a bb
+}
+
+do_preupdate_test 7.3.4.1 {
+  UPDATE OR REPLACE t3 SET i = 5 WHERE i = 6
+} {
+  DELETE main t3 2 2   5 25
+  UPDATE main t3 3 3   6 36  5 36
+}
+
+do_execsql_test 7.3.4.2 {
+  INSERT INTO t3 VALUES(10, 100);
+  SELECT rowid, * FROM t3;
+} {1 4 16   3 5 36   4 10 100}
+
+do_preupdate_test 7.3.5 {
+  UPDATE OR REPLACE t3 SET rowid = 1, i = 5 WHERE j = 100;
+} {
+  DELETE main t3 1 1    4  16
+  DELETE main t3 3 3    5  36
+  UPDATE main t3 4 1   10 100  5 100
+}
+
+do_execsql_test 7.4.1.0 {
+  CREATE TABLE t4(a, b);
+  INSERT INTO t4 VALUES('a', 1);
+  INSERT INTO t4 VALUES('b', 2);
+  INSERT INTO t4 VALUES('c', 3);
+
+  CREATE TRIGGER t4t BEFORE DELETE ON t4 BEGIN
+    DELETE FROM t4 WHERE b = 1;
+  END;
+}
+
+do_preupdate_test 7.4.1.1 {
+  DELETE FROM t4 WHERE b = 3
+} {
+  DELETE main t4 1 1   a 1
+  DELETE main t4 3 3   c 3
+}
+
+do_execsql_test 7.4.1.2 {
+  INSERT INTO t4(rowid, a, b) VALUES(1, 'a', 1);
+  INSERT INTO t4(rowid, a, b) VALUES(3, 'c', 3);
+}
+do_preupdate_test 7.4.1.3 {
+  DELETE FROM t4 WHERE b = 1
+} {
+  DELETE main t4 1 1   a 1
+}
+
+do_execsql_test 7.4.2.0 {
+  CREATE TABLE t5(a, b);
+  INSERT INTO t5 VALUES('a', 1);
+  INSERT INTO t5 VALUES('b', 2);
+  INSERT INTO t5 VALUES('c', 3);
+
+  CREATE TRIGGER t5t BEFORE UPDATE ON t5 BEGIN
+    DELETE FROM t5 WHERE b = 1;
+  END;
+}
+do_preupdate_test 7.4.2.1 {
+  UPDATE t5 SET b = 4 WHERE a = 'c'
+} {
+  DELETE main t5 1 1   a 1
+  UPDATE main t5 3 3   c 3  c 4
+}
+
+do_execsql_test 7.4.2.2 {
+  INSERT INTO t5(rowid, a, b) VALUES(1, 'a', 1);
+}
+
+do_preupdate_test 7.4.2.3 {
+  UPDATE t5 SET b = 5 WHERE a = 'a'
+} {
+  DELETE main t5 1 1   a 1
+}
+
+do_execsql_test 7.5.1.0 {
+  CREATE TABLE t7(a, b);
+  INSERT INTO t7 VALUES('one', 'two');
+  INSERT INTO t7 VALUES('three', 'four');
+  ALTER TABLE t7 ADD COLUMN c DEFAULT NULL;
+}
+
+do_preupdate_test 7.5.1.1 {
+  DELETE FROM t7 WHERE a = 'one'
+} {
+  DELETE main t7 1 1   one two {}
+}
+
+do_preupdate_test 7.5.1.2 {
+  UPDATE t7 SET b = 'five'
+} {
+  UPDATE main t7 2 2   three four {}  three five {}
+}
+
+do_execsql_test 7.5.2.0 {
+  CREATE TABLE t8(a, b);
+  INSERT INTO t8 VALUES('one', 'two');
+  INSERT INTO t8 VALUES('three', 'four');
+  ALTER TABLE t8 ADD COLUMN c DEFAULT 'xxx';
+}
+
+# At time of writing, these two are broken. They demonstrate that the
+# sqlite3_preupdate_old() method does not handle the case where ALTER TABLE
+# has been used to add a column with a default value other than NULL.
+#
+do_preupdate_test 7.5.2.1 {
+  DELETE FROM t8 WHERE a = 'one'
+} {
+  DELETE main t8 1 1   one two xxx
+}
+do_preupdate_test 7.5.2.2 {
+  UPDATE t8 SET b = 'five'
+} {
+  UPDATE main t8 2 2   three four xxx  three five xxx
+}
+
+# This block of tests verifies that IPK values are correctly reported
+# by the sqlite3_preupdate_old() and sqlite3_preupdate_new() functions.
+#
+do_execsql_test 7.6.1 { CREATE TABLE t9(a, b INTEGER PRIMARY KEY, c) }
+do_preupdate_test 7.6.2 {
+  INSERT INTO t9 VALUES(1, 2, 3);
+  UPDATE t9 SET b = b+1, c = c+1;
+  DELETE FROM t9 WHERE a = 1;
+} {
+  INSERT main t9 2 2   1 2 3
+  UPDATE main t9 2 3   1 2 3   1 3 4
+  DELETE main t9 3 3   1 3 4
+}
+
+#--------------------------------------------------------------------------
+# Test that the sqlite3_preupdate_depth() API seems to work.
+#
+proc preupdate_hook {args} {
+  set type [lindex $args 0]
+  eval lappend ::preupdate $args
+  eval lappend ::preupdate [db preupdate depth]
+
+  if {$type != "INSERT"} {
+    for {set i 0} {$i < [db preupdate count]} {incr i} {
+      lappend ::preupdate [db preupdate old $i]
+    }
+  }
+  if {$type != "DELETE"} {
+    for {set i 0} {$i < [db preupdate count]} {incr i} {
+      set rc [catch { db preupdate new $i } v]
+      lappend ::preupdate $v
+    }
+  }
+}
+
+db close
+forcedelete test.db
+sqlite3 db test.db
+db preupdate hook preupdate_hook
+
+do_execsql_test 7.6.1 { 
+  CREATE TABLE t1(x PRIMARY KEY);
+  CREATE TABLE t2(x PRIMARY KEY);
+  CREATE TABLE t3(x PRIMARY KEY);
+  CREATE TABLE t4(x PRIMARY KEY);
+
+  CREATE TRIGGER a AFTER INSERT ON t1 BEGIN INSERT INTO t2 VALUES(new.x); END;
+  CREATE TRIGGER b AFTER INSERT ON t2 BEGIN INSERT INTO t3 VALUES(new.x); END;
+  CREATE TRIGGER c AFTER INSERT ON t3 BEGIN INSERT INTO t4 VALUES(new.x); END;
+
+  CREATE TRIGGER d AFTER UPDATE ON t1 BEGIN UPDATE t2 SET x = new.x; END;
+  CREATE TRIGGER e AFTER UPDATE ON t2 BEGIN UPDATE t3 SET x = new.x; END;
+  CREATE TRIGGER f AFTER UPDATE ON t3 BEGIN UPDATE t4 SET x = new.x; END;
+
+  CREATE TRIGGER g AFTER DELETE ON t1 BEGIN DELETE FROM t2 WHERE 1; END;
+  CREATE TRIGGER h AFTER DELETE ON t2 BEGIN DELETE FROM t3 WHERE 1; END;
+  CREATE TRIGGER i AFTER DELETE ON t3 BEGIN DELETE FROM t4 WHERE 1; END;
+}
+
+do_preupdate_test 7.6.2 {
+  INSERT INTO t1 VALUES('xyz');
+} {
+  INSERT main t1 1 1   0      xyz
+  INSERT main t2 1 1   1      xyz
+  INSERT main t3 1 1   2      xyz
+  INSERT main t4 1 1   3      xyz
+}
+do_preupdate_test 7.6.3 {
+  UPDATE t1 SET x = 'abc';
+} {
+  UPDATE main t1 1 1   0      xyz abc
+  UPDATE main t2 1 1   1      xyz abc
+  UPDATE main t3 1 1   2      xyz abc
+  UPDATE main t4 1 1   3      xyz abc
+}
+do_preupdate_test 7.6.4 {
+  DELETE FROM t1 WHERE 1;
+} {
+  DELETE main t1 1 1   0      abc
+  DELETE main t2 1 1   1      abc
+  DELETE main t3 1 1   2      abc
+  DELETE main t4 1 1   3      abc
+}
+
+do_execsql_test 7.6.5 { 
+  DROP TRIGGER a; DROP TRIGGER b; DROP TRIGGER c;
+  DROP TRIGGER d; DROP TRIGGER e; DROP TRIGGER f;
+  DROP TRIGGER g; DROP TRIGGER h; DROP TRIGGER i;
+
+  CREATE TRIGGER a BEFORE INSERT ON t1 BEGIN INSERT INTO t2 VALUES(new.x); END;
+  CREATE TRIGGER b BEFORE INSERT ON t2 BEGIN INSERT INTO t3 VALUES(new.x); END;
+  CREATE TRIGGER c BEFORE INSERT ON t3 BEGIN INSERT INTO t4 VALUES(new.x); END;
+
+  CREATE TRIGGER d BEFORE UPDATE ON t1 BEGIN UPDATE t2 SET x = new.x; END;
+  CREATE TRIGGER e BEFORE UPDATE ON t2 BEGIN UPDATE t3 SET x = new.x; END;
+  CREATE TRIGGER f BEFORE UPDATE ON t3 BEGIN UPDATE t4 SET x = new.x; END;
+
+  CREATE TRIGGER g BEFORE DELETE ON t1 BEGIN DELETE FROM t2 WHERE 1; END;
+  CREATE TRIGGER h BEFORE DELETE ON t2 BEGIN DELETE FROM t3 WHERE 1; END;
+  CREATE TRIGGER i BEFORE DELETE ON t3 BEGIN DELETE FROM t4 WHERE 1; END;
+}
+
+do_preupdate_test 7.6.6 {
+  INSERT INTO t1 VALUES('xyz');
+} {
+  INSERT main t4 1 1   3      xyz
+  INSERT main t3 1 1   2      xyz
+  INSERT main t2 1 1   1      xyz
+  INSERT main t1 1 1   0      xyz
+}
+do_preupdate_test 7.6.3 {
+  UPDATE t1 SET x = 'abc';
+} {
+  UPDATE main t4 1 1   3      xyz abc
+  UPDATE main t3 1 1   2      xyz abc
+  UPDATE main t2 1 1   1      xyz abc
+  UPDATE main t1 1 1   0      xyz abc
+}
+do_preupdate_test 7.6.4 {
+  DELETE FROM t1 WHERE 1;
+} {
+  DELETE main t4 1 1   3      abc
+  DELETE main t3 1 1   2      abc
+  DELETE main t2 1 1   1      abc
+  DELETE main t1 1 1   0      abc
+}
+
 finish_test

test/permutations.test

@@ -89,6 +89,9 @@ foreach f [glob $testdir/*.test] { lappend alltests [file tail $f] }
 foreach f [glob -nocomplain $testdir/../ext/rtree/*.test] { 
   lappend alltests $f 
 }
+foreach f [glob -nocomplain $testdir/../ext/session/*.test] { 
+  lappend alltests $f 
+}
 
 if {$::tcl_platform(platform)!="unix"} {
   set alltests [test_set $alltests -exclude crash.test crash2.test]
@@ -96,7 +99,7 @@ if {$::tcl_platform(platform)!="unix"} {
 set alltests [test_set $alltests -exclude {
   all.test        async.test         quick.test  veryquick.test
   memleak.test    permutations.test  soak.test   fts3.test
-  mallocAll.test  rtree.test         full.test
+  mallocAll.test  rtree.test         full.test   session.test
 }]
 
 set allquicktests [test_set $alltests -exclude {
@@ -893,6 +896,18 @@ test_suite "rtree" -description {
   All R-tree related tests. Provides coverage of source file rtree.c.
 } -files [glob -nocomplain $::testdir/../ext/rtree/*.test]
 
+test_suite "session" -description {
+  All session module related tests. 
+} -files [glob -nocomplain $::testdir/../ext/session/*.test]
+
+test_suite "session_eec" -description {
+  All session module related tests with sqlite3_extended_result_codes() set. 
+} -files [
+  glob -nocomplain $::testdir/../ext/session/*.test
+] -dbconfig {
+  sqlite3_extended_result_codes $::dbhandle 1
+}
+
 test_suite "no_optimization" -description {
   Run test scripts with optimizations disabled using the
   sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS) interface.

test/session.test

@@ -0,0 +1,21 @@
+# 2008 June 23
+#
+#    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 runs all rtree related tests.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/permutations.test
+
+ifcapable session {
+  # First run tests with sqlite3_extended_error_codes() set, then
+  # again with it clear.
+  run_test_suite session_eec
+  run_test_suite session
+}
+
+finish_test

test/show_speedtest1_rtree.tcl

@@ -0,0 +1,57 @@
+#!/usr/bin/tclsh
+#
+# This script displays the field of rectangles used by --testset rtree
+# of speedtest1.  Run this script as follows:
+#
+#      rm test.db
+#      ./speedtest1 --testset rtree --size 25 test.db
+#      sqlite3 --separator ' ' test.db 'SELECT * FROM rt1' >data.txt
+#      wish show_speedtest1_rtree.tcl
+#
+# The filename "data.txt" is hard coded into this script and so that name
+# must be used on lines 3 and 4 above.  Elsewhere, different filenames can
+# be used.  The --size N parameter can be adjusted as desired.
+#
+package require Tk
+set f [open data.txt rb]
+set data [read $f]
+close $f
+canvas .c
+frame .b
+button .b.b1 -text X-Y -command refill-xy
+button .b.b2 -text X-Z -command refill-xz
+button .b.b3 -text Y-Z -command refill-yz
+pack .b.b1 .b.b2 .b.b3 -side left
+pack .c -side top -fill both -expand 1
+pack .b -side top
+proc resize_canvas_to_fit {} {
+  foreach {x0 y0 x1 y1} [.c bbox all] break
+  set w [expr {$x1-$x0}]
+  set h [expr {$y1-$y0}]
+  .c config -width $w -height $h
+}
+proc refill-xy {} {
+  .c delete all
+  foreach {id x0 x1 y0 y1 z0 z1} $::data {
+    .c create rectangle $x0 $y0 $x1 $y1
+  }
+  .c scale all 0 0 0.05 0.05
+  resize_canvas_to_fit
+}
+proc refill-xz {} {
+  .c delete all
+  foreach {id x0 x1 y0 y1 z0 z1} $::data {
+    .c create rectangle $x0 $z0 $x1 $z1
+  }
+  .c scale all 0 0 0.05 0.05
+  resize_canvas_to_fit
+}
+proc refill-yz {} {
+  .c delete all
+  foreach {id x0 x1 y0 y1 z0 z1} $::data {
+    .c create rectangle $y0 $z0 $y1 $z1
+  }
+  .c scale all 0 0 0.05 0.05
+  resize_canvas_to_fit
+}
+refill-xy

test/speedtest1.c

@@ -29,6 +29,7 @@ static const char zHelp[] =
   "  --trace             Turn on SQL tracing\n"
   "  --utf16be           Set text encoding to UTF-16BE\n"
   "  --utf16le           Set text encoding to UTF-16LE\n"
+  "  --verify            Run additional verification steps.\n"
   "  --without-rowid     Use WITHOUT ROWID where appropriate\n"
 ;
 
@@ -51,6 +52,7 @@ static struct Global {
   int bReprepare;            /* True to reprepare the SQL on each rerun */
   int bSqlOnly;              /* True to print the SQL once only */
   int bExplain;              /* Print SQL with EXPLAIN prefix */
+  int bVerify;               /* Try to verify that results are correct */
   int szTest;                /* Scale factor for test iterations */
   const char *zWR;           /* Might be WITHOUT ROWID */
   const char *zNN;           /* Might be NOT NULL */
@@ -931,6 +933,183 @@ void testset_cte(void){
 
 }
 
+/* Generate two numbers between 1 and mx.  The first number is less than
+** the second.  Usually the numbers are near each other but can sometimes
+** be far apart.
+*/
+static void twoCoords(
+  int p1, int p2,                   /* Parameters adjusting sizes */
+  unsigned mx,                      /* Range of 1..mx */
+  unsigned *pX0, unsigned *pX1      /* OUT: write results here */
+){
+  unsigned d, x0, x1, span;
+
+  span = mx/100 + 1;
+  if( speedtest1_random()%3==0 ) span *= p1;
+  if( speedtest1_random()%p2==0 ) span = mx/2;
+  d = speedtest1_random()%span + 1;
+  x0 = speedtest1_random()%(mx-d) + 1;
+  x1 = x0 + d;
+  *pX0 = x0;
+  *pX1 = x1;
+}
+
+/* The following routine is an R-Tree geometry callback.  It returns
+** true if the object overlaps a slice on the Y coordinate between the
+** two values given as arguments.  In other words
+**
+**     SELECT count(*) FROM rt1 WHERE id MATCH xslice(10,20);
+**
+** Is the same as saying:
+**
+**     SELECT count(*) FROM rt1 WHERE y1>=10 AND y0<=20;
+*/
+static int xsliceGeometryCallback(
+  sqlite3_rtree_geometry *p,
+  int nCoord,
+  double *aCoord,
+  int *pRes
+){
+  *pRes = aCoord[3]>=p->aParam[0] && aCoord[2]<=p->aParam[1];
+  return SQLITE_OK;
+}
+
+/*
+** A testset for the R-Tree virtual table
+*/
+void testset_rtree(int p1, int p2){
+  unsigned i, n;
+  unsigned mxCoord;
+  unsigned x0, x1, y0, y1, z0, z1;
+  unsigned iStep;
+  int *aCheck = sqlite3_malloc( sizeof(int)*g.szTest*100 );
+
+  mxCoord = 15000;
+  n = g.szTest*100;
+  speedtest1_begin_test(100, "%d INSERTs into an r-tree", n);
+  speedtest1_exec("BEGIN");
+  speedtest1_exec("CREATE VIRTUAL TABLE rt1 USING rtree(id,x0,x1,y0,y1,z0,z1)");
+  speedtest1_prepare("INSERT INTO rt1(id,x0,x1,y0,y1,z0,z1)"
+                     "VALUES(?1,?2,?3,?4,?5,?6,?7)");
+  for(i=1; i<=n; i++){
+    twoCoords(p1, p2, mxCoord, &x0, &x1);
+    twoCoords(p1, p2, mxCoord, &y0, &y1);
+    twoCoords(p1, p2, mxCoord, &z0, &z1);
+    sqlite3_bind_int(g.pStmt, 1, i);
+    sqlite3_bind_int(g.pStmt, 2, x0);
+    sqlite3_bind_int(g.pStmt, 3, x1);
+    sqlite3_bind_int(g.pStmt, 4, y0);
+    sqlite3_bind_int(g.pStmt, 5, y1);
+    sqlite3_bind_int(g.pStmt, 6, z0);
+    sqlite3_bind_int(g.pStmt, 7, z1);
+    speedtest1_run();
+  }
+  speedtest1_exec("COMMIT");
+  speedtest1_end_test();
+
+  speedtest1_begin_test(101, "Copy from rtree to a regular table");
+  speedtest1_exec("CREATE TABLE t1(id INTEGER PRIMARY KEY,x0,x1,y0,y1,z0,z1)");
+  speedtest1_exec("INSERT INTO t1 SELECT * FROM rt1");
+  speedtest1_end_test();
+
+  n = g.szTest*20;
+  speedtest1_begin_test(110, "%d one-dimensional intersect slice queries", n);
+  speedtest1_prepare("SELECT count(*) FROM rt1 WHERE x0>=?1 AND x1<=?2");
+  iStep = mxCoord/n;
+  for(i=0; i<n; i++){
+    sqlite3_bind_int(g.pStmt, 1, i*iStep);
+    sqlite3_bind_int(g.pStmt, 2, (i+1)*iStep);
+    speedtest1_run();
+    aCheck[i] = atoi(g.zResult);
+  }
+  speedtest1_end_test();
+
+  if( g.bVerify ){
+    n = g.szTest*20;
+    speedtest1_begin_test(111, "Verify result from 1-D intersect slice queries");
+    speedtest1_prepare("SELECT count(*) FROM t1 WHERE x0>=?1 AND x1<=?2");
+    iStep = mxCoord/n;
+    for(i=0; i<n; i++){
+      sqlite3_bind_int(g.pStmt, 1, i*iStep);
+      sqlite3_bind_int(g.pStmt, 2, (i+1)*iStep);
+      speedtest1_run();
+      if( aCheck[i]!=atoi(g.zResult) ){
+        fatal_error("Count disagree step %d: %d..%d.  %d vs %d",
+                    i, i*iStep, (i+1)*iStep, aCheck[i], atoi(g.zResult));
+      }
+    }
+    speedtest1_end_test();
+  }
+  
+  n = g.szTest*20;
+  speedtest1_begin_test(120, "%d one-dimensional overlap slice queries", n);
+  speedtest1_prepare("SELECT count(*) FROM rt1 WHERE y1>=?1 AND y0<=?2");
+  iStep = mxCoord/n;
+  for(i=0; i<n; i++){
+    sqlite3_bind_int(g.pStmt, 1, i*iStep);
+    sqlite3_bind_int(g.pStmt, 2, (i+1)*iStep);
+    speedtest1_run();
+    aCheck[i] = atoi(g.zResult);
+  }
+  speedtest1_end_test();
+
+  if( g.bVerify ){
+    n = g.szTest*20;
+    speedtest1_begin_test(121, "Verify result from 1-D overlap slice queries");
+    speedtest1_prepare("SELECT count(*) FROM t1 WHERE y1>=?1 AND y0<=?2");
+    iStep = mxCoord/n;
+    for(i=0; i<n; i++){
+      sqlite3_bind_int(g.pStmt, 1, i*iStep);
+      sqlite3_bind_int(g.pStmt, 2, (i+1)*iStep);
+      speedtest1_run();
+      if( aCheck[i]!=atoi(g.zResult) ){
+        fatal_error("Count disagree step %d: %d..%d.  %d vs %d",
+                    i, i*iStep, (i+1)*iStep, aCheck[i], atoi(g.zResult));
+      }
+    }
+    speedtest1_end_test();
+  }
+  
+
+  n = g.szTest*20;
+  speedtest1_begin_test(125, "%d custom geometry callback queries", n);
+  sqlite3_rtree_geometry_callback(g.db, "xslice", xsliceGeometryCallback, 0);
+  speedtest1_prepare("SELECT count(*) FROM rt1 WHERE id MATCH xslice(?1,?2)");
+  iStep = mxCoord/n;
+  for(i=0; i<n; i++){
+    sqlite3_bind_int(g.pStmt, 1, i*iStep);
+    sqlite3_bind_int(g.pStmt, 2, (i+1)*iStep);
+    speedtest1_run();
+    if( aCheck[i]!=atoi(g.zResult) ){
+      fatal_error("Count disagree step %d: %d..%d.  %d vs %d",
+                  i, i*iStep, (i+1)*iStep, aCheck[i], atoi(g.zResult));
+    }
+  }
+  speedtest1_end_test();
+
+  n = g.szTest*80;
+  speedtest1_begin_test(130, "%d three-dimensional intersect box queries", n);
+  speedtest1_prepare("SELECT count(*) FROM rt1 WHERE x1>=?1 AND x0<=?2"
+                     " AND y1>=?1 AND y0<=?2 AND z1>=?1 AND z0<=?2");
+  iStep = mxCoord/n;
+  for(i=0; i<n; i++){
+    sqlite3_bind_int(g.pStmt, 1, i*iStep);
+    sqlite3_bind_int(g.pStmt, 2, (i+1)*iStep);
+    speedtest1_run();
+    aCheck[i] = atoi(g.zResult);
+  }
+  speedtest1_end_test();
+
+  n = g.szTest*100;
+  speedtest1_begin_test(140, "%d rowid queries", n);
+  speedtest1_prepare("SELECT * FROM rt1 WHERE id=?1");
+  for(i=1; i<=n; i++){
+    sqlite3_bind_int(g.pStmt, 1, i);
+    speedtest1_run();
+  }
+  speedtest1_end_test();
+}
+
 /*
 ** A testset used for debugging speedtest1 itself.
 */
@@ -1050,6 +1229,8 @@ int main(int argc, char **argv){
         zEncoding = "utf16le";
       }else if( strcmp(z,"utf16be")==0 ){
         zEncoding = "utf16be";
+      }else if( strcmp(z,"verify")==0 ){
+        g.bVerify = 1;
       }else if( strcmp(z,"without-rowid")==0 ){
         g.zWR = "WITHOUT ROWID";
         g.zPK = "PRIMARY KEY";
@@ -1141,8 +1322,11 @@ int main(int argc, char **argv){
     testset_debug1();
   }else if( strcmp(zTSet,"cte")==0 ){
     testset_cte();
+  }else if( strcmp(zTSet,"rtree")==0 ){
+    testset_rtree(6, 147);
   }else{
-    fatal_error("unknown testset: \"%s\"\n", zTSet);
+    fatal_error("unknown testset: \"%s\"\nChoices: main debug1 cte rtree\n",
+                 zTSet);
   }
   speedtest1_final();
 

test/tclsqlite.test

@@ -35,7 +35,7 @@ do_test tcl-1.1 {
 do_test tcl-1.2 {
   set v [catch {db bogus} msg]
   lappend v $msg
-} {1 {bad option "bogus": must be authorizer, backup, busy, cache, changes, close, collate, collation_needed, commit_hook, complete, copy, enable_load_extension, errorcode, eval, exists, function, incrblob, interrupt, last_insert_rowid, nullvalue, onecolumn, profile, progress, rekey, restore, rollback_hook, status, timeout, total_changes, trace, transaction, unlock_notify, update_hook, version, or wal_hook}}
+} {1 {bad option "bogus": must be authorizer, backup, busy, cache, changes, close, collate, collation_needed, commit_hook, complete, copy, enable_load_extension, errorcode, eval, exists, function, incrblob, interrupt, last_insert_rowid, nullvalue, onecolumn, preupdate, profile, progress, rekey, restore, rollback_hook, status, timeout, total_changes, trace, transaction, unlock_notify, update_hook, version, or wal_hook}}
 do_test tcl-1.2.1 {
   set v [catch {db cache bogus} msg]
   lappend v $msg

test/tester.tcl

@@ -710,6 +710,12 @@ proc fix_testname {varname} {
   }
 }
 
+proc normalize_list {L} {
+  set L2 [list]
+  foreach l $L {lappend L2 $l}
+  set L2
+}
+
 proc do_execsql_test {testname sql {result {}}} {
   fix_testname testname
   uplevel do_test [list $testname] [list "execsql {$sql}"] [list [list {*}$result]]

tool/mksqlite3c.tcl

@@ -108,6 +108,7 @@ foreach hdr {
    parse.h
    pcache.h
    rtree.h
+   sqlite3session.h
    sqlite3ext.h
    sqlite3.h
    sqliteicu.h
@@ -121,6 +122,7 @@ foreach hdr {
   set available_hdr($hdr) 1
 }
 set available_hdr(sqliteInt.h) 0
+set available_hdr(sqlite3session.h) 0
 
 # 78 stars used for comment formatting.
 set s78 \
@@ -188,7 +190,7 @@ proc copy_file {filename} {
       if {[regexp $declpattern $line all funcname]} {
         # Add the SQLITE_PRIVATE or SQLITE_API keyword before functions.
         # so that linkage can be modified at compile-time.
-        if {[regexp {^sqlite3_} $funcname]} {
+        if {[regexp {^sqlite3[a-z]*_} $funcname]} {
           puts $out "SQLITE_API $line"
         } else {
           puts $out "SQLITE_PRIVATE $line"
@@ -327,6 +329,8 @@ foreach file {
    rtree.c
    icu.c
    fts3_icu.c
+
+   sqlite3session.c
 } {
   copy_file tsrc/$file
 }

tool/mksqlite3h.tcl

@@ -71,12 +71,16 @@ fconfigure stdout -translation lf
 set filelist [subst {
   $TOP/src/sqlite.h.in
   $TOP/ext/rtree/sqlite3rtree.h
+  $TOP/ext/session/sqlite3session.h
 }]
 
 # Process the source files.
 #
 foreach file $filelist {
   set in [open $file]
+  if {![regexp {sqlite\.h\.in} $file]} {
+    puts "/******** Begin file [file tail $file] *********/"
+  }
   while {![eof $in]} {
   
     set line [gets $in]
@@ -108,4 +112,7 @@ foreach file $filelist {
     puts $line
   }
   close $in
+  if {![regexp {sqlite\.h\.in} $file]} {
+    puts "/******** End of [file tail $file] *********/"
+  }
 }

tool/symbols.sh

@@ -10,7 +10,7 @@ gcc -c -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE \
   -DSQLITE_ENABLE_MEMORY_MANAGEMENT -DSQLITE_ENABLE_STAT3 \
   -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_ENABLE_UNLOCK_NOTIFY \
   -DSQLITE_ENABLE_COLUMN_METADATA -DSQLITE_ENABLE_ATOMIC_WRITE \
-  -DSQLITE_ENABLE_ICU \
+  -DSQLITE_ENABLE_ICU -DSQLITE_ENABLE_PREUPDATE_HOOK -DSQLITE_ENABLE_SESSION \
   sqlite3.c
 nm sqlite3.o | grep ' [TD] ' | sort -k 3