Add experimental API sqlite3session_diff().

FossilOrigin-Name: c4340b2ea2115ad97dcac036f9034e132ab789e5

Makefile.in

@@ -30,7 +30,8 @@ BCC = @BUILD_CC@ @BUILD_CFLAGS@
 #
 CC = @CC@
 CFLAGS = @CPPFLAGS@ @CFLAGS@
-TCC = $(CC) $(CFLAGS) -I. -I${TOP}/src -I${TOP}/ext/rtree -I${TOP}/ext/fts3
+TCC = ${CC} ${CFLAGS} -I. -I${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
@@ -80,6 +81,7 @@ 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)
 
@@ -180,7 +182,8 @@ 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 threads.lo tokenize.lo trigger.lo \
          update.lo util.lo vacuum.lo \
          vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
@@ -338,6 +341,10 @@ 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
@@ -395,7 +402,8 @@ 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
 #
@@ -456,7 +464,8 @@ 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.
 #
@@ -572,6 +581,7 @@ mptest:	mptester$(EXE)
 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
@@ -923,6 +933,9 @@ 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.
 #
@@ -998,6 +1011,9 @@ showjournal$(TEXE):	$(TOP)/tool/showjournal.c sqlite3.lo
 showwal$(TEXE):	$(TOP)/tool/showwal.c sqlite3.lo
 	$(LTLINK) -o $@ $(TOP)/tool/showwal.c sqlite3.lo $(TLIBS)
 
+changeset$(TEXE):	$(TOP)/ext/session/changeset.c sqlite3.lo
+	$(LTLINK) -o $@ $(TOP)/ext/session/changeset.c sqlite3.lo $(TLIBS)
+
 rollback-test$(TEXE):	$(TOP)/tool/rollback-test.c sqlite3.lo
 	$(LTLINK) -o $@ $(TOP)/tool/rollback-test.c sqlite3.lo $(TLIBS)
 
@@ -1079,7 +1095,7 @@ clean:
 	rm -f testfixture$(TEXE) test.db
 	rm -f LogEst$(TEXE) fts3view$(TEXE) rollback-test$(TEXE) showdb$(TEXE)
 	rm -f showjournal$(TEXE) showstat4$(TEXE) showwal$(TEXE) speedtest1$(TEXE)
-	rm -f wordcount$(TEXE)
+	rm -f wordcount$(TEXE) changeset$(TEXE)
 	rm -f sqlite3.dll sqlite3.lib sqlite3.exp sqlite3.def
 	rm -f sqlite3.c
 	rm -f sqlite3rc.h

Makefile.msc

@@ -446,6 +446,8 @@ 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
@@ -608,6 +610,14 @@ RCC = $(RCC) -DSQLITE_TEMP_STORE=1
 # The same set of OMIT and ENABLE flags should be passed to the
 # LEMON parser generator and the mkkeywordhash tool as well.
 
+# BEGIN standard options
+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
+
 # These are the required SQLite compilation options used when compiling for
 # the Windows platform.
 #
@@ -795,7 +805,8 @@ 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 threads.lo tokenize.lo trigger.lo \
          update.lo util.lo vacuum.lo \
          vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
@@ -961,7 +972,9 @@ SRC4 = \
   $(TOP)\ext\icu\sqliteicu.h \
   $(TOP)\ext\icu\icu.c \
   $(TOP)\ext\rtree\rtree.h \
-  $(TOP)\ext\rtree\rtree.c
+  $(TOP)\ext\rtree\rtree.c \
+  $(TOP)\ext\session\sqlite3session.h \
+  $(TOP)\ext\session\sqlite3session.c
 
 
 # Generated source code files
@@ -1022,7 +1035,8 @@ 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
 #
@@ -1042,6 +1056,7 @@ TESTEXT = \
 
 
 # Source code to the library files needed by the test fixture
+# (non-amalgamation)
 #
 TESTSRC2 = \
   $(TOP)\src\attach.c \
@@ -1087,7 +1102,14 @@ 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.
 #
@@ -1138,6 +1160,8 @@ 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.
@@ -1195,6 +1219,7 @@ 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
@@ -1564,6 +1589,9 @@ fts3_write.lo:	$(TOP)\ext\fts3\fts3_write.c $(HDR) $(EXTHDR)
 rtree.lo:	$(TOP)\ext\rtree\rtree.c $(HDR) $(EXTHDR)
 	$(LTCOMPILE) $(CORE_COMPILE_OPTS) $(NO_WARN) -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.
 #
@@ -1577,7 +1605,7 @@ TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_SERVER=1 -DSQLITE_PRIVATE=""
 TESTFIXTURE_FLAGS = $(TESTFIXTURE_FLAGS) -DSQLITE_CORE $(NO_WARN)
 
 TESTFIXTURE_SRC0 = $(TESTEXT) $(TESTSRC2) $(SHELL_CORE_DEP)
-TESTFIXTURE_SRC1 = $(TESTEXT) $(SQLITE3C)
+TESTFIXTURE_SRC1 = $(TESTEXT) $(TESTSRC3) $(SQLITE3C)
 !IF $(USE_AMALGAMATION)==0
 TESTFIXTURE_SRC = $(TESTSRC) $(TOP)\src\tclsqlite.c $(TESTFIXTURE_SRC0)
 !ELSE
@@ -1641,6 +1669,10 @@ showwal.exe:	$(TOP)\tool\showwal.c $(SQLITE3C)
 	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -Fe$@ \
 		$(TOP)\tool\showwal.c $(SQLITE3C)
 
+changeset.exe:	$(TOP)\ext\session\changeset.c $(SQLITE3C)
+	$(LTLINK) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -Fe$@ \
+		$(TOP)\ext\session\changeset.c $(SQLITE3C)
+
 fts3view.exe:	$(TOP)\ext\fts3\tool\fts3view.c $(SQLITE3C)
 	$(LTLINK) $(NO_WARN) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -Fe$@ \
 		$(TOP)\ext\fts3\tool\fts3view.c $(SQLITE3C)
@@ -1678,6 +1710,7 @@ clean:
 	del /Q testloadext.dll 2>NUL
 	del /Q testfixture.exe test.db 2>NUL
 	del /Q LogEst.exe fts3view.exe rollback-test.exe showdb.exe 2>NUL
+	del /Q changeset.exe 2>NUL
 	del /Q showjournal.exe showstat4.exe showwal.exe speedtest1.exe 2>NUL
 	del /Q mptester.exe wordcount.exe 2>NUL
 	del /Q sqlite3.exe sqlite3.dll sqlite3.def 2>NUL

ext/session/changeset.c

@@ -0,0 +1,416 @@
+/*
+** 2014-08-18
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains code to implement the "changeset" command line
+** utility for displaying and transforming changesets generated by
+** the Sessions extension.
+*/
+#include "sqlite3.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <ctype.h>
+
+
+/*
+** Show a usage message on stderr then quit.
+*/
+static void usage(const char *argv0){
+  fprintf(stderr, "Usage: %s FILENAME COMMAND ...\n", argv0);
+  fprintf(stderr,
+    "COMMANDs:\n"
+    "   apply DB           Apply the changeset to database file DB\n"
+    "   concat FILE2 OUT   Concatenate FILENAME and FILE2 into OUT\n"
+    "   dump               Show the complete content of the changeset\n"
+    "   invert OUT         Write an inverted changeset into file OUT\n"
+    "   sql                Give a pseudo-SQL rendering of the changeset\n"
+  );
+  exit(1);
+}
+
+/*
+** Read the content of a disk file into an in-memory buffer
+*/
+static void readFile(const char *zFilename, int *pSz, void **ppBuf){
+  FILE *f;
+  int sz;
+  void *pBuf;
+  f = fopen(zFilename, "rb");
+  if( f==0 ){
+    fprintf(stderr, "cannot open \"%s\" for reading\n", zFilename);
+    exit(1);
+  }
+  fseek(f, 0, SEEK_END);
+  sz = (int)ftell(f);
+  rewind(f);
+  pBuf = sqlite3_malloc( sz ? sz : 1 );
+  if( pBuf==0 ){
+    fprintf(stderr, "cannot allocate %d to hold content of \"%s\"\n",
+            sz, zFilename);
+    exit(1);
+  }
+  if( sz>0 ){
+    if( fread(pBuf, sz, 1, f)!=1 ){
+      fprintf(stderr, "cannot read all %d bytes of \"%s\"\n", sz, zFilename);
+      exit(1);
+    }
+    fclose(f);
+  }
+  *pSz = sz;
+  *ppBuf = pBuf;
+}
+
+/* Array for converting from half-bytes (nybbles) into ASCII hex
+** digits. */
+static const char hexdigits[] = {
+  '0', '1', '2', '3', '4', '5', '6', '7',
+  '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' 
+};
+
+/*
+** Render an sqlite3_value as an SQL string.
+*/
+static void renderValue(sqlite3_value *pVal){
+  switch( sqlite3_value_type(pVal) ){
+    case SQLITE_FLOAT: {
+      double r1;
+      char zBuf[50];
+      r1 = sqlite3_value_double(pVal);
+      sqlite3_snprintf(sizeof(zBuf), zBuf, "%!.15g", r1);
+      printf("%s", zBuf);
+      break;
+    }
+    case SQLITE_INTEGER: {
+      printf("%lld", sqlite3_value_int64(pVal));
+      break;
+    }
+    case SQLITE_BLOB: {
+      char const *zBlob = sqlite3_value_blob(pVal);
+      int nBlob = sqlite3_value_bytes(pVal);
+      int i;
+      printf("x'");
+      for(i=0; i<nBlob; i++){
+        putchar(hexdigits[(zBlob[i]>>4)&0x0F]);
+        putchar(hexdigits[(zBlob[i])&0x0F]);
+      }
+      putchar('\'');
+      break;
+    }
+    case SQLITE_TEXT: {
+      const unsigned char *zArg = sqlite3_value_text(pVal);
+      putchar('\'');
+      while( zArg[0] ){
+        putchar(zArg[0]);
+        if( zArg[0]=='\'' ) putchar(zArg[0]);
+        zArg++;
+      }
+      putchar('\'');
+      break;
+    }
+    default: {
+      assert( sqlite3_value_type(pVal)==SQLITE_NULL );
+      printf("NULL");
+      break;
+    }
+  }
+}
+
+/*
+** Number of conflicts seen
+*/
+static int nConflict = 0;
+
+/*
+** The conflict callback
+*/
+static int conflictCallback(
+  void *pCtx,
+  int eConflict,
+  sqlite3_changeset_iter *pIter
+){
+  int op, bIndirect, nCol, i;
+  const char *zTab;
+  unsigned char *abPK;
+  const char *zType = "";
+  const char *zOp = "";
+  const char *zSep = " ";
+
+  nConflict++;
+  sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
+  sqlite3changeset_pk(pIter, &abPK, 0);
+  switch( eConflict ){
+    case SQLITE_CHANGESET_DATA:         zType = "DATA";         break;
+    case SQLITE_CHANGESET_NOTFOUND:     zType = "NOTFOUND";     break;
+    case SQLITE_CHANGESET_CONFLICT:     zType = "PRIMARY KEY";  break;
+    case SQLITE_CHANGESET_FOREIGN_KEY:  zType = "FOREIGN KEY";  break;
+    case SQLITE_CHANGESET_CONSTRAINT:   zType = "CONSTRAINT";   break;
+  }
+  switch( op ){
+    case SQLITE_UPDATE:     zOp = "UPDATE of";     break;
+    case SQLITE_INSERT:     zOp = "INSERT into";   break;
+    case SQLITE_DELETE:     zOp = "DELETE from";   break;
+  }
+  printf("%s conflict on %s table %s with primary key", zType, zOp, zTab);
+  for(i=0; i<nCol; i++){
+    sqlite3_value *pVal;
+    if( abPK[i]==0 ) continue;
+    printf("%s", zSep);
+    if( op==SQLITE_INSERT ){
+      sqlite3changeset_new(pIter, i, &pVal);
+    }else{
+      sqlite3changeset_old(pIter, i, &pVal);
+    }
+    renderValue(pVal);
+    zSep = ",";
+  }
+  printf("\n");
+  return SQLITE_CHANGESET_OMIT;
+}
+
+int main(int argc, char **argv){
+  int sz, rc;
+  void *pBuf = 0;
+  if( argc<3 ) usage(argv[0]);
+  readFile(argv[1], &sz, &pBuf);
+
+  /* changeset FILENAME apply DB
+  ** Apply the changeset in FILENAME to the database file DB
+  */
+  if( strcmp(argv[2],"apply")==0 ){
+    sqlite3 *db;
+    if( argc!=4 ) usage(argv[0]);
+    rc = sqlite3_open(argv[3], &db);
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "unable to open database file \"%s\": %s\n",
+              argv[3], sqlite3_errmsg(db));
+      sqlite3_close(db);
+      exit(1);
+    }
+    sqlite3_exec(db, "BEGIN", 0, 0, 0);
+    nConflict = 0;
+    rc = sqlite3changeset_apply(db, sz, pBuf, 0, conflictCallback, 0);
+    if( rc ){
+      fprintf(stderr, "sqlite3changeset_apply() returned %d\n", rc);
+    }
+    if( nConflict ){
+      fprintf(stderr, "%d conflicts - no changes applied\n", nConflict);
+      sqlite3_exec(db, "ROLLBACK", 0, 0, 0);
+    }else if( rc ){
+      fprintf(stderr, "sqlite3changeset_apply() returns %d "
+                      "- no changes applied\n", rc);
+      sqlite3_exec(db, "ROLLBACK", 0, 0, 0);
+    }else{
+      sqlite3_exec(db, "COMMIT", 0, 0, 0);
+    }
+    sqlite3_close(db);
+  }else
+
+  /* changeset FILENAME concat FILE2 OUT
+  ** Add changeset FILE2 onto the end of the changeset in FILENAME
+  ** and write the result into OUT.
+  */
+  if( strcmp(argv[2],"concat")==0 ){
+    int szB;
+    void *pB;
+    int szOut;
+    void *pOutBuf;
+    FILE *out;
+    const char *zOut = argv[4];
+    if( argc!=5 ) usage(argv[0]);
+    out = fopen(zOut, "wb");
+    if( out==0 ){
+      fprintf(stderr, "cannot open \"%s\" for writing\n", zOut);
+      exit(1);
+    }
+    readFile(argv[3], &szB, &pB);
+    rc = sqlite3changeset_concat(sz, pBuf, szB, pB, &szOut, &pOutBuf);
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "sqlite3changeset_concat() returns %d\n", rc);
+    }else if( szOut>0 && fwrite(pOutBuf, szOut, 1, out)!=1 ){
+      fprintf(stderr, "unable to write all %d bytes of output to \"%s\"\n",
+              szOut, zOut);
+    }
+    fclose(out);
+    sqlite3_free(pOutBuf);
+    sqlite3_free(pB);
+  }else
+
+  /* changeset FILENAME dump
+  ** Show the complete content of the changeset in FILENAME
+  */
+  if( strcmp(argv[2],"dump")==0 ){
+    int cnt = 0;
+    int i;
+    sqlite3_changeset_iter *pIter;
+    rc = sqlite3changeset_start(&pIter, sz, pBuf);
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "sqlite3changeset_start() returns %d\n", rc);
+      exit(1);
+    }
+    while( sqlite3changeset_next(pIter)==SQLITE_ROW ){
+      int op, bIndirect, nCol;
+      const char *zTab;
+      unsigned char *abPK;
+      sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
+      cnt++;
+      printf("%d: %s table=[%s] indirect=%d nColumn=%d\n",
+             cnt, op==SQLITE_INSERT ? "INSERT" :
+                       op==SQLITE_UPDATE ? "UPDATE" : "DELETE",
+             zTab, bIndirect, nCol);
+      sqlite3changeset_pk(pIter, &abPK, 0);
+      for(i=0; i<nCol; i++){
+        sqlite3_value *pVal;
+        pVal = 0;
+        sqlite3changeset_old(pIter, i, &pVal);
+        if( pVal ){
+          printf("    old[%d]%s = ", i, abPK[i] ? "pk" : "  ");
+          renderValue(pVal);
+          printf("\n");
+        }
+        pVal = 0;
+        sqlite3changeset_new(pIter, i, &pVal);
+        if( pVal ){
+          printf("    new[%d]%s = ", i, abPK[i] ? "pk" : "  ");
+          renderValue(pVal);
+          printf("\n");
+        }
+      }
+    }
+    sqlite3changeset_finalize(pIter);
+  }else
+
+  /* changeset FILENAME invert OUT
+  ** Invert the changes in FILENAME and writes the result on OUT
+  */
+  if( strcmp(argv[2],"invert")==0 ){
+    FILE *out;
+    int szOut = 0;
+    void *pOutBuf = 0;
+    const char *zOut = argv[3];
+    if( argc!=4 ) usage(argv[0]);
+    out = fopen(zOut, "wb");
+    if( out==0 ){
+      fprintf(stderr, "cannot open \"%s\" for writing\n", zOut);
+      exit(1);
+    }
+    rc = sqlite3changeset_invert(sz, pBuf, &szOut, &pOutBuf);
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "sqlite3changeset_invert() returns %d\n", rc);
+    }else if( szOut>0 && fwrite(pOutBuf, szOut, 1, out)!=1 ){
+      fprintf(stderr, "unable to write all %d bytes of output to \"%s\"\n",
+              szOut, zOut);
+    }
+    fclose(out);
+    sqlite3_free(pOutBuf);
+  }else
+
+  /* changeset FILE sql
+  ** Show the content of the changeset as pseudo-SQL
+  */
+  if( strcmp(argv[2],"sql")==0 ){
+    int cnt = 0;
+    char *zPrevTab = 0;
+    char *zSQLTabName = 0;
+    sqlite3_changeset_iter *pIter = 0;
+    rc = sqlite3changeset_start(&pIter, sz, pBuf);
+    if( rc!=SQLITE_OK ){
+      fprintf(stderr, "sqlite3changeset_start() returns %d\n", rc);
+      exit(1);
+    }
+    printf("BEGIN;\n");
+    while( sqlite3changeset_next(pIter)==SQLITE_ROW ){
+      int op, bIndirect, nCol;
+      const char *zTab;
+      sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
+      cnt++;
+      if( zPrevTab==0 || strcmp(zPrevTab,zTab)!=0 ){
+        sqlite3_free(zPrevTab);
+        sqlite3_free(zSQLTabName);
+        zPrevTab = sqlite3_mprintf("%s", zTab);
+        if( !isalnum(zTab[0]) || sqlite3_strglob("*[^a-zA-Z0-9]*",zTab)==0 ){
+          zSQLTabName = sqlite3_mprintf("\"%w\"", zTab);
+        }else{
+          zSQLTabName = sqlite3_mprintf("%s", zTab);
+        }
+        printf("/****** Changes for table %s ***************/\n", zSQLTabName);
+      }
+      switch( op ){
+        case SQLITE_DELETE: {
+          unsigned char *abPK;
+          int i;
+          const char *zSep = " ";
+          sqlite3changeset_pk(pIter, &abPK, 0);
+          printf("/* %d */ DELETE FROM %s WHERE", cnt, zSQLTabName);
+          for(i=0; i<nCol; i++){
+            sqlite3_value *pVal;
+            if( abPK[i]==0 ) continue;
+            printf("%sc%d=", zSep, i+1);
+            zSep = " AND ";
+            sqlite3changeset_old(pIter, i, &pVal);
+            renderValue(pVal);
+          }
+          printf(";\n");
+          break;
+        }
+        case SQLITE_UPDATE: {
+          unsigned char *abPK;
+          int i;
+          const char *zSep = " ";
+          sqlite3changeset_pk(pIter, &abPK, 0);
+          printf("/* %d */ UPDATE %s SET", cnt, zSQLTabName);
+          for(i=0; i<nCol; i++){
+            sqlite3_value *pVal = 0;
+            sqlite3changeset_new(pIter, i, &pVal);
+            if( pVal ){
+              printf("%sc%d=", zSep, i+1);
+              zSep = ", ";
+              renderValue(pVal);
+            }
+          }
+          printf(" WHERE");
+          zSep = " ";
+          for(i=0; i<nCol; i++){
+            sqlite3_value *pVal;
+            if( abPK[i]==0 ) continue;
+            printf("%sc%d=", zSep, i+1);
+            zSep = " AND ";
+            sqlite3changeset_old(pIter, i, &pVal);
+            renderValue(pVal);
+          }
+          printf(";\n");
+          break;
+        }
+        case SQLITE_INSERT: {
+          int i;
+          printf("/* %d */ INSERT INTO %s VALUES", cnt, zSQLTabName);
+          for(i=0; i<nCol; i++){
+            sqlite3_value *pVal;
+            printf("%c", i==0 ? '(' : ',');
+            sqlite3changeset_new(pIter, i, &pVal);
+            renderValue(pVal);
+          }
+          printf(");\n");
+          break;
+        }
+      }
+    }
+    printf("COMMIT;\n");
+    sqlite3changeset_finalize(pIter);
+    sqlite3_free(zPrevTab);
+    sqlite3_free(zSQLTabName);
+  }else
+
+  /* If nothing else matches, show the usage comment */
+  usage(argv[0]);
+  sqlite3_free(pBuf);
+  return 0; 
+}

ext/session/session1.test

@@ -0,0 +1,553 @@
+# 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_test 8.5 {
+  sqlite3session S db main
+  S attach t5
+  S attach t6
+  execsql { INSERT INTO t5 VALUES(1, 2) }
+  S isempty
+} {0}
+
+do_test 8.6 {
+  S delete
+  sqlite3session S db main
+  S attach t5
+  S attach t6
+  execsql { INSERT INTO t6 VALUES(1, 2) }
+  S isempty
+} {0}
+do_test 8.7 { 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 }
+ 
+#-------------------------------------------------------------------------
+# Test a really long table name.
+#
+reset_db
+set tblname [string repeat tblname123 100]
+do_test 10.1.1 {
+  execsql "
+    CREATE TABLE $tblname (a PRIMARY KEY, b);
+    INSERT INTO $tblname VALUES('xyz', 'def');
+  "
+  sqlite3session S db main
+  S attach $tblname
+  execsql " 
+    INSERT INTO $tblname VALUES('uvw', 'abc');
+    DELETE FROM $tblname WHERE a = 'xyz';
+  "
+} {}
+breakpoint
+do_changeset_test 10.1.2 S "
+  {INSERT $tblname 0 X. {} {t uvw t abc}}
+  {DELETE $tblname 0 X. {t xyz t def} {}}
+"
+do_test 10.1.4 { S delete } {}
+
+
+finish_test

ext/session/session2.test

@@ -0,0 +1,591 @@
+# 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 }
+
+  19 { 
+    INSERT INTO t1 VALUES('', '');
+    INSERT INTO t1 VALUES(X'', X'');
+  }
+  20 { 
+    DELETE FROM t1;
+    INSERT INTO t1 VALUES('', NULL);
+  }
+}
+
+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 +1,408 @@
+# 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 +1,91 @@
+# 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 +1,287 @@
+# 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 {}}
+
+#--------------------------------------------------------------------
+# Test that if a DELETE change cannot be applied due to an 
+# SQLITE_CONSTRAINT error thrown by a trigger program, things do not
+# go awry.
+
+drop_all_tables
+reset_db
+do_execsql_test 5.1 {
+  CREATE TABLE x1(x PRIMARY KEY, y);
+  CREATE TABLE x2(x PRIMARY KEY, y);
+  INSERT INTO x2 VALUES(1, 1);
+  INSERT INTO x1 VALUES(1, 1);
+}
+
+set ::cc [changeset_from_sql { DELETE FROM x1; }]
+
+do_execsql_test 5.2 {
+  INSERT INTO x1 VALUES(1, 1);
+  CREATE TRIGGER tr1 AFTER DELETE ON x1 BEGIN
+    INSERT INTO x2 VALUES(old.x, old.y);
+  END;
+} {}
+
+proc conflict_handler {args} { return "ABORT" }
+do_test 5.3 {
+  list [catch {sqlite3changeset_apply db $::cc conflict_handler} msg] $msg
+} {1 SQLITE_ABORT}
+
+do_execsql_test 5.4 {
+  SELECT * FROM X1;
+} {1 1}
+
+finish_test

ext/session/sessionA.test

@@ -0,0 +1,106 @@
+# 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 filter callbacks work 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}
+
+#-------------------------------------------------------------------------
+# Test that filter callbacks passed to sqlite3changeset_apply() are 
+# invoked correctly.
+#
+reset_db
+do_execsql_test 3.1 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t2(x PRIMARY KEY, y);
+}
+
+do_test 3.2 {
+  execsql BEGIN
+  set ::cs [changeset_from_sql { 
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t2 VALUES('x', 'y');
+  }]
+  execsql ROLLBACK
+  set {} {}
+} {}
+
+proc filter {x y} { 
+  return [string equal $x $y] 
+}
+
+do_test 3.3 {
+  sqlite3changeset_apply db $::cs {} [list filter t1]
+  execsql {
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+  }
+} {1 2}
+
+do_test 3.4 {
+  execsql { DELETE FROM t1 }
+  sqlite3changeset_apply db $::cs {} [list filter t2]
+  execsql {
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+  }
+} {x y}
+
+finish_test

ext/session/sessionB.test

@@ -0,0 +1,518 @@
+# 2014 August 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.
+#
+#***********************************************************************
+#
+# This file implements regression tests for sessions SQLite extension.
+# Specifically, this file contains tests for "patchset" changes.
+#
+
+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 sessionB
+
+#
+# 1.*: Test that the blobs returned by the session_patchset() API are 
+#      as expected. Also the sqlite3_changeset_iter functions.
+#
+# 2.*: Test that patchset blobs are handled by sqlite3changeset_apply().
+#
+# 3.*: Test that sqlite3changeset_invert() works with patchset blobs. 
+#      Correct behaviour is to return SQLITE_CORRUPT.
+
+proc do_patchset_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 patchset] { lappend x [set c] }
+    set x
+  }]] [list $r]
+}
+
+proc do_sql2patchset_test {tn sql res} {
+  sqlite3session S db main
+  S attach *
+  execsql $sql
+  uplevel [list do_patchset_test $tn S $res]
+  S delete
+}
+
+#-------------------------------------------------------------------------
+# Run simple tests of the _patchset() API.
+#
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a, b, c, d, PRIMARY KEY(d, a));
+  INSERT INTO t1 VALUES(1, 2, 3, 4);
+  INSERT INTO t1 VALUES(5, 6, 7, 8);
+  INSERT INTO t1 VALUES(9, 10, 11, 12);
+}
+
+do_test 1.1 {
+  sqlite3session S db main
+  S attach t1
+  execsql {
+    INSERT INTO t1 VALUES('w', 'x', 'y', 'z');
+    DELETE FROM t1 WHERE d=4;
+    UPDATE t1 SET c = 14 WHERE a=5;
+  }
+} {}
+
+do_patchset_test 1.2 S {
+  {UPDATE t1 0 X..X {i 5 {} {} {} {} i 8} {{} {} {} {} i 14 {} {}}}
+  {INSERT t1 0 X..X {} {t w t x t y t z}}
+  {DELETE t1 0 X..X {i 1 {} {} {} {} i 4} {}}
+}
+
+do_test 1.3 {
+  S delete
+} {}
+
+do_sql2patchset_test 1.4 {
+  DELETE FROM t1;
+} {
+  {DELETE t1 0 X..X {i 5 {} {} {} {} i 8} {}}
+  {DELETE t1 0 X..X {t w {} {} {} {} t z} {}}
+  {DELETE t1 0 X..X {i 9 {} {} {} {} i 12} {}}
+}
+
+do_sql2patchset_test 1.5 {
+  INSERT INTO t1 VALUES(X'61626364', NULL, NULL, 4.2);
+  INSERT INTO t1 VALUES(4.2, NULL, NULL, X'61626364');
+} {
+  {INSERT t1 0 X..X {} {f 4.2 n {} n {} b abcd}} 
+  {INSERT t1 0 X..X {} {b abcd n {} n {} f 4.2}}
+}
+
+do_sql2patchset_test 1.6 {
+  UPDATE t1 SET b=45 WHERE typeof(a)=='blob';
+  UPDATE t1 SET c='zzzz' WHERE typeof(a)!='blob';
+} {
+  {UPDATE t1 0 X..X {f 4.2 {} {} {} {} b abcd} {{} {} {} {} t zzzz {} {}}}
+  {UPDATE t1 0 X..X {b abcd {} {} {} {} f 4.2} {{} {} i 45 {} {} {} {}}}
+}
+
+do_sql2patchset_test 1.7 {
+  UPDATE t1 SET b='xyz' WHERE typeof(a)=='blob';
+  UPDATE t1 SET c='xyz' WHERE typeof(a)!='blob';
+  UPDATE t1 SET b=45 WHERE typeof(a)=='blob';
+  UPDATE t1 SET c='zzzz' WHERE typeof(a)!='blob';
+} {
+}
+
+do_sql2patchset_test 1.8 {
+  DELETE FROM t1;
+} {
+  {DELETE t1 0 X..X {f 4.2 {} {} {} {} b abcd} {}} 
+  {DELETE t1 0 X..X {b abcd {} {} {} {} f 4.2} {}}
+}
+
+#-------------------------------------------------------------------------
+# Run simple tests of _apply() with patchset objects.
+#
+reset_db
+
+proc noop {args} { error $args }
+proc exec_rollback_replay {sql} {
+  sqlite3session S db main
+  S attach *
+  execsql BEGIN
+  execsql $sql
+  set patchset [S patchset]
+  S delete
+  execsql ROLLBACK
+  sqlite3changeset_apply db $patchset noop
+}
+
+do_execsql_test 2.0 {
+  CREATE TABLE t2(a, b, c, d, PRIMARY KEY(b,c));
+  CREATE TABLE t3(w, x, y, z, PRIMARY KEY(w));
+}
+
+do_test 2.1 {
+  exec_rollback_replay {
+    INSERT INTO t2 VALUES(1, 2, 3, 4);
+    INSERT INTO t2 VALUES('w', 'x', 'y', 'z');
+  }
+  execsql { SELECT * FROM t2 }
+} {1 2 3 4 w x y z}
+
+do_test 2.2 {
+  exec_rollback_replay {
+    DELETE FROM t2 WHERE a=1;
+    UPDATE t2 SET d = 'a';
+  }
+  execsql { SELECT * FROM t2 }
+} {w x y a}
+
+#-------------------------------------------------------------------------
+# sqlite3changeset_invert()
+#
+reset_db
+
+do_execsql_test 3.1 { CREATE TABLE t1(x PRIMARY KEY, y) }
+do_test 3.2 {
+  sqlite3session S db main
+  S attach *
+  execsql { INSERT INTO t1 VALUES(1, 2) }
+  set patchset [S patchset]
+  S delete
+  list [catch { sqlite3changeset_invert $patchset } msg] [set msg]
+} {1 SQLITE_CORRUPT}
+
+
+#-------------------------------------------------------------------------
+# sqlite3changeset_concat()
+#
+reset_db
+
+proc do_patchconcat_test {tn args} {
+  set bRevert 0
+  if {[lindex $args 0] == "-revert"} {
+    set bRevert 1
+    set args [lrange $args 1 end]
+  }
+  set nSql [expr [llength $args]-1]
+  set res [lindex $args $nSql]
+  set patchlist [list]
+
+  execsql BEGIN
+  if {$bRevert} { execsql { SAVEPOINT x } }
+  foreach sql [lrange $args 0 end-1] {
+    sqlite3session S db main
+    S attach *
+    execsql $sql
+    lappend patchlist [S patchset]
+    S delete
+    if {$bRevert} { execsql { ROLLBACK TO x } }
+  }
+  execsql ROLLBACK
+
+  set patch [lindex $patchlist 0]
+  foreach p [lrange $patchlist 1 end] {
+    set patch [sqlite3changeset_concat $patch $p]
+  }
+
+  set x [list]
+  sqlite3session_foreach c $patch { lappend x $c }
+
+  uplevel [list do_test $tn [list set {} $x] [list {*}$res]]
+}
+
+do_execsql_test 4.1.1 {
+  CREATE TABLE t1(x PRIMARY KEY, y, z);
+}
+do_patchconcat_test 4.1.2 {
+  INSERT INTO t1 VALUES(1, 2, 3);
+} {
+  INSERT INTO t1 VALUES(4, 5, 6);
+} {
+  {INSERT t1 0 X.. {} {i 1 i 2 i 3}} 
+  {INSERT t1 0 X.. {} {i 4 i 5 i 6}}
+}
+
+do_execsql_test 4.2.1 {
+  INSERT INTO t1 VALUES(1, 2, 3);
+  INSERT INTO t1 VALUES(4, 5, 6);
+}
+
+do_patchconcat_test 4.2.2 {
+  UPDATE t1 SET z = 'abc' WHERE x=1
+} {
+  UPDATE t1 SET z = 'def' WHERE x=4
+} {
+  {UPDATE t1 0 X.. {i 1 {} {} {} {}} {{} {} {} {} t abc}} 
+  {UPDATE t1 0 X.. {i 4 {} {} {} {}} {{} {} {} {} t def}}
+}
+
+do_patchconcat_test 4.2.3 {
+  DELETE FROM t1 WHERE x=1;
+} {
+  DELETE FROM t1 WHERE x=4;
+} {
+  {DELETE t1 0 X.. {i 1 {} {} {} {}} {}} 
+  {DELETE t1 0 X.. {i 4 {} {} {} {}} {}}
+}
+
+
+do_execsql_test 4.3.1 {
+  CREATE TABLE t2(a, b, c, d, PRIMARY KEY(c, b));
+  INSERT INTO t2 VALUES('.', 1, 1, '.');
+  INSERT INTO t2 VALUES('.', 1, 2, '.');
+  INSERT INTO t2 VALUES('.', 2, 1, '.');
+  INSERT INTO t2 VALUES('.', 2, 2, '.');
+}
+
+# INSERT + INSERT 
+do_patchconcat_test 4.3.2 -revert {
+  INSERT INTO t2 VALUES('a', 'a', 'a', 'a');
+} {
+  INSERT INTO t2 VALUES('b', 'a', 'a', 'b');
+} {
+  {INSERT t2 0 .XX. {} {t a t a t a t a}}
+}
+
+# INSERT + DELETE 
+do_patchconcat_test 4.3.3 {
+  INSERT INTO t2 VALUES('a', 'a', 'a', 'a');
+} {
+  DELETE FROM t2 WHERE c = 'a';
+} {
+}
+
+# INSERT + UPDATE
+do_patchconcat_test 4.3.4 {
+  INSERT INTO t2 VALUES('a', 'a', 'a', 'a');
+} {
+  UPDATE t2 SET d = 'b' WHERE c='a';
+} {
+  {INSERT t2 0 .XX. {} {t a t a t a t b}}
+}
+
+# UPDATE + UPDATE
+do_patchconcat_test 4.3.5 {
+  UPDATE t2 SET a = 'a' WHERE c=1 AND b=2;
+} {
+  UPDATE t2 SET d = 'd' WHERE c=1 AND b=2;
+} {
+  {UPDATE t2 0 .XX. {{} {} i 2 i 1 {} {}} {t a {} {} {} {} t d}}
+}
+
+# UPDATE + DELETE
+do_patchconcat_test 4.3.6 {
+  UPDATE t2 SET a = 'a' WHERE c=1 AND b=2;
+} {
+  DELETE FROM t2 WHERE c=1 AND b=2;
+} {
+  {DELETE t2 0 .XX. {{} {} i 2 i 1 {} {}} {}}
+}
+
+# DELETE + INSERT
+do_patchconcat_test 4.3.7 {
+  DELETE FROM t2 WHERE b=1;
+} {
+  INSERT INTO t2 VALUES('x', 1, 2, '.');
+} {
+  {DELETE t2 0 .XX. {{} {} i 1 i 1 {} {}} {}} 
+  {UPDATE t2 0 .XX. {{} {} i 1 i 2 {} {}} {t x {} {} {} {} t .}}
+}
+
+# DELETE + UPDATE
+do_patchconcat_test 4.3.8 -revert {
+  DELETE FROM t2 WHERE b=1 AND c=2;
+} {
+  UPDATE t2 SET a=5 WHERE b=1 AND c=2;
+} {
+  {DELETE t2 0 .XX. {{} {} i 1 i 2 {} {}} {}} 
+}
+
+# DELETE + UPDATE
+do_patchconcat_test 4.3.9 -revert {
+  DELETE FROM t2 WHERE b=1 AND c=2;
+} {
+  DELETE FROM t2 WHERE b=1;
+} {
+  {DELETE t2 0 .XX. {{} {} i 1 i 1 {} {}} {}} 
+  {DELETE t2 0 .XX. {{} {} i 1 i 2 {} {}} {}} 
+}
+
+#-------------------------------------------------------------------------
+# More rigorous testing of the _patchset(), _apply and _concat() APIs.
+#
+# The inputs to each test are a populate database and a list of DML 
+# statements. This test determines that the final database is the same
+# if:
+# 
+#   1) the statements are executed directly on the database.
+#
+#   2) a single patchset is collected while executing the statements and
+#      then applied to a copy of the original database file.
+#
+#   3) individual patchsets are collected for statement while executing
+#      them and concatenated together before being applied to a copy of
+#      the original database. The concatenation is done in a couple of
+#      different ways - linear, pairwise etc.
+#
+# All tests, as it happens, are run with both changesets and patchsets.
+# But the focus is on patchset capabilities.
+#
+
+# Return a checksum of the contents of the database file. Implicit IPK
+# columns are not included in the checksum - just modifying rowids does
+# not change the database checksum.
+#
+proc databasecksum {db} {
+  set alltab [$db eval {SELECT name FROM sqlite_master WHERE type='table'}]
+  foreach tab $alltab {
+    $db eval "SELECT * FROM $tab LIMIT 1" res { }
+    set slist [list]
+    foreach col [lsort $res(*)] {
+      lappend slist "quote($col)"
+    }
+    set sql "SELECT [join $slist ,] FROM $tab"
+    append txt "[lsort [$db eval $sql]]\n"
+  }
+  return [md5 $txt]
+}
+
+proc do_patchset_test {tn tstcmd lSql} {
+  if {$tstcmd != "patchset" && $tstcmd != "changeset"} {
+    error "have $tstcmd: must be patchset or changeset"
+  }
+
+  foreach fname {test.db2 test.db3 test.db4 test.db5} {
+    forcedelete $fname
+    forcecopy test.db $fname
+  }
+
+  # Execute the SQL statements on [db]. Collect a patchset for each 
+  # individual statement, as well as a single patchset for the entire 
+  # operation.
+  sqlite3session S db main
+  S attach *
+  foreach sql $lSql { 
+    sqlite3session T db main
+    T attach *
+    db eval $sql 
+    lappend lPatch [T $tstcmd]
+    T delete
+  }
+  set patchset [S $tstcmd]
+  S delete
+
+  # Calculate a checksum for the final database.
+  set cksum [databasecksum db]
+
+  # 1. Apply the single large patchset to test.db2
+  sqlite3 db2 test.db2
+  sqlite3changeset_apply db2 $patchset noop
+  uplevel [list do_test $tn.1 { databasecksum db2 } $cksum ]
+  db2 close
+  
+  # 2. Apply each of the single-statement patchsets to test.db3
+  sqlite3 db2 test.db3
+  foreach p $lPatch {
+    sqlite3changeset_apply db2 $p noop
+  }
+  uplevel [list do_test $tn.2 { databasecksum db2 } $cksum ]
+  db2 close
+
+  # 3. Concatenate all single-statement patchsets into a single large
+  #    patchset, then apply it to test.db4.
+  #
+  sqlite3 db2 test.db4
+  set big ""
+  foreach p $lPatch {
+    set big [sqlite3changeset_concat $big $p]
+  }
+  sqlite3changeset_apply db2 $big noop
+  uplevel [list do_test $tn.3 { databasecksum db2 } $cksum ]
+  db2 close
+
+  # 4. Concatenate all single-statement patchsets pairwise into a single
+  #    large patchset, then apply it to test.db5. Pairwise concatenation:
+  #
+  #         a b c d e f g h i j k
+  #      -> {a b} {c d} {e f} {g h} {i j} k
+  #      -> {a b c d} {e f g h} {i j k}
+  #      -> {a b c d e f g h} {i j k}
+  #      -> {a b c d e f g h i j k}
+  #      -> APPLY!
+  #
+  sqlite3 db2 test.db5
+  set L $lPatch
+  while {[llength $L] > 1} {
+    set O [list]
+    for {set i 0} {$i < [llength $L]} {incr i 2} {
+      if {$i==[llength $L]-1} {
+        lappend O [lindex $L $i]
+      } else {
+        set i1 [expr $i+1]
+        lappend O [sqlite3changeset_concat [lindex $L $i] [lindex $L $i1]]
+      }
+    }
+    set L $O
+  }
+  sqlite3changeset_apply db2 [lindex $L 0] noop
+  uplevel [list do_test $tn.4 { databasecksum db2 } $cksum ]
+  db2 close
+}
+
+proc do_patchset_changeset_test {tn initsql args} {
+  foreach tstcmd {patchset changeset} {
+    reset_db
+    execsql $initsql
+    set x 0
+    foreach sql $args {
+      incr x
+      set lSql [split $sql ";"]
+      uplevel [list do_patchset_test $tn.$tstcmd.$x $tstcmd $lSql]
+    }
+  }
+}
+
+do_patchset_changeset_test 5.1 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c);
+  INSERT INTO t1 VALUES(1, 2, 3);
+} {
+  INSERT INTO t1 VALUES(4, 5, 6);
+  DELETE FROM t1 WHERE a=1;
+} {
+  INSERT INTO t1 VALUES(7, 8, 9);
+  UPDATE t1 SET c = 5;
+  INSERT INTO t1 VALUES(10, 11, 12);
+  UPDATE t1 SET c = 6;
+  INSERT INTO t1 VALUES(13, 14, 15);
+} {
+  UPDATE t1 SET c=c+1;
+  DELETE FROM t1 WHERE (a%2);
+} 
+
+do_patchset_changeset_test 5.2 {
+  CREATE TABLE t1(a PRIMARY KEY, b, c);
+  CREATE TABLE t2(a, b, c, d, PRIMARY KEY(c, b));
+} {
+  INSERT INTO t1 VALUES(x'00', 0, 'zero');
+  INSERT INTO t1 VALUES(x'01', 1, 'one');
+  INSERT INTO t1 VALUES(x'02', 4, 'four');
+  INSERT INTO t1 VALUES(x'03', 9, 'nine');
+  INSERT INTO t1 VALUES(x'04', 16, 'sixteen');
+  INSERT INTO t1 VALUES(x'05', 25, 'twenty-five');
+} {
+  UPDATE t1 SET a = b WHERE b<=4;
+  INSERT INTO t2 SELECT NULL, * FROM t1;
+  DELETE FROM t1 WHERE b=25;
+} {
+  DELETE FROM t2;
+  INSERT INTO t2 SELECT NULL, * FROM t1;
+  DELETE FROM t1;
+  INSERT INTO t1 SELECT b, c, d FROM t2;
+  UPDATE t1 SET b = b+1;
+  UPDATE t1 SET b = b+1;
+  UPDATE t1 SET b = b+1;
+}
+
+set initsql { CREATE TABLE t1(a, b, c, PRIMARY KEY(c, b)); }
+for {set i 0} {$i < 1000} {incr i} {
+  append insert "INSERT INTO t1 VALUES($i, $i, $i);"
+  append delete "DELETE FROM t1 WHERE b=$i;"
+}
+do_patchset_changeset_test 5.3 \
+  $initsql $insert $delete     \
+  $insert $delete              \
+  "$insert $delete"            \
+  $delete
+
+
+finish_test

ext/session/sessionC.test

@@ -0,0 +1,190 @@
+# 2014 August 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.
+#
+#***********************************************************************
+#
+#
+
+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 sessionC
+
+#-------------------------------------------------------------------------
+# Test the outcome of a DELETE operation made as part of applying a
+# changeset failing with SQLITE_CONSTRAINT. This may happen if an
+# ON DELETE RESTRICT foreign key action is triggered, or if a trigger
+# program raises a constraint somehow.
+#
+do_execsql_test 1.0 {
+  PRAGMA foreign_keys = 1;
+
+  CREATE TABLE p(a PRIMARY KEY, b, c);
+  CREATE TABLE c(d PRIMARY KEY, e REFERENCES p ON DELETE RESTRICT);
+
+  INSERT INTO p VALUES('one', 1, 1);
+  INSERT INTO p VALUES('two', 2, 2);
+  INSERT INTO p VALUES('three', 3, 3);
+
+  INSERT INTO c VALUES(1, 'one');
+  INSERT INTO c VALUES(3, 'three');
+}
+
+do_test 1.1 {
+  execsql BEGIN
+  set C [changeset_from_sql {
+    INSERT INTO c VALUES(4, 'one');
+    DELETE FROM p WHERE a='two';
+  }]
+  execsql ROLLBACK
+  execsql {
+    INSERT INTO c VALUES(2, 'two');
+  }
+} {}
+
+do_test 1.2.1 {
+  proc xConflict {args} { return "ABORT" }
+  catch { sqlite3changeset_apply db $C xConflict } msg
+  set msg
+} {SQLITE_ABORT}
+do_execsql_test 1.2.2 { SELECT * FROM c } {1 one 3 three 2 two}
+
+do_test 1.3.1 {
+  proc xConflict {args} { return "OMIT" }
+  catch { sqlite3changeset_apply db $C xConflict } msg
+  set msg
+} {}
+do_execsql_test 1.3.2 { SELECT * FROM c } {1 one 3 three 2 two 4 one}
+do_execsql_test 1.3.3 { 
+  SELECT * FROM p;
+} {one 1 1 two 2 2 three 3 3}
+
+
+#-------------------------------------------------------------------------
+# Test that concatenating a changeset with a patchset does not work.
+# Any attempt to do so returns SQLITE_ERROR.
+#
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE x1(t, v PRIMARY KEY);
+  INSERT INTO x1 VALUES(12, 55);
+  INSERT INTO x1 VALUES(55, 14);
+}
+
+do_test 2.1 {
+  execsql BEGIN
+
+  sqlite3session S1 db main
+  S1 attach *
+  execsql {
+    UPDATE x1 SET t=13 WHERE v=55;
+    INSERT INTO x1 VALUES(99, 123);
+  }
+  set patchset [S1 patchset]
+  S1 delete
+
+  sqlite3session S1 db main
+  S1 attach *
+  execsql {
+    UPDATE x1 SET t=56 WHERE v=14;
+    INSERT INTO x1 VALUES(22, 998);
+  }
+  set changeset [S1 changeset]
+  S1 delete
+
+  execsql ROLLBACK
+} {}
+
+do_test 2.2 {
+  set rc [catch { sqlite3changeset_concat $patchset $changeset } msg]
+  list $rc $msg
+} {1 SQLITE_ERROR}
+
+do_test 2.3 {
+  set rc [catch { sqlite3changeset_concat $changeset $patchset } msg]
+  list $rc $msg
+} {1 SQLITE_ERROR}
+
+do_test 2.4 {
+  set rc [catch { sqlite3changeset_concat {} $patchset } msg]
+  list $rc $msg
+} [list 0 $patchset]
+
+do_test 2.5 {
+  set rc [catch { sqlite3changeset_concat $patchset {} } msg]
+  list $rc $msg
+} [list 0 $patchset]
+
+do_test 2.6 {
+  set rc [catch { sqlite3changeset_concat {} $changeset } msg]
+  list $rc $msg
+} [list 0 $changeset]
+
+do_test 2.7 {
+  set rc [catch { sqlite3changeset_concat $changeset {} } msg]
+  list $rc $msg
+} [list 0 $changeset]
+
+do_test 2.8 {
+  set rc [catch { sqlite3changeset_concat {} {} } msg]
+  list $rc $msg
+} [list 0 {}]
+
+
+#-------------------------------------------------------------------------
+# Test that the xFilter argument to sqlite3changeset_apply() works.
+#
+reset_db
+do_execsql_test 3.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  CREATE TABLE t3(a PRIMARY KEY, b);
+}
+do_test 3.1 {
+  execsql BEGIN
+  set changeset [changeset_from_sql {
+    INSERT INTO t1 VALUES(1, 1);
+    INSERT INTO t2 VALUES(2, 2);
+    INSERT INTO t3 VALUES(3, 3);
+  }]
+  execsql ROLLBACK
+} {}
+do_test 3.2 {
+  proc xFilter {zName} {
+    if {$zName == "t1"} { return 1 }
+    return 0
+  }
+  sqlite3changeset_apply db $changeset noop xFilter
+  execsql {
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+    SELECT * FROM t3;
+  }
+} {1 1}
+do_test 3.3 {
+  proc xFilter {zName} {
+    if {$zName == "t3"} { return 1 }
+    return 0
+  }
+  sqlite3changeset_apply db $changeset noop xFilter
+  execsql {
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+    SELECT * FROM t3;
+  }
+} {1 1 3 3}
+
+
+
+finish_test
+

ext/session/sessionD.test

@@ -0,0 +1,150 @@
+# 2014 August 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.
+#
+#***********************************************************************
+# This file focuses on the sqlite3session_diff() function.
+#
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] session_common.tcl]
+source $testdir/tester.tcl
+ifcapable !session {finish_test; return}
+
+set testprefix sessionD
+
+proc scksum {db dbname} {
+
+  if {$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 ORDER BY type,name,sql"]
+  foreach tab $alltab {
+    set cols [list]
+    db eval "PRAGMA $dbname.table_info = $tab" x { 
+      lappend cols "quote($x(name))" 
+    }
+    set cols [join $cols ,]
+    append txt [db eval "SELECT $cols FROM $tab ORDER BY $cols"]
+  }
+  return [md5 $txt]
+}
+
+proc do_diff_test {tn setup} {
+  reset_db
+  forcedelete test.db2
+  execsql { ATTACH 'test.db2' AS aux }
+  execsql $setup
+
+  sqlite3session S db main
+  foreach tbl [db eval {SELECT name FROM sqlite_master WHERE type='table'}] {
+    S attach $tbl
+    S diff aux $tbl
+  }
+
+  set C [S changeset]
+  S delete
+
+  sqlite3 db2 test.db2
+  sqlite3changeset_apply db2 $C ""
+  uplevel do_test $tn.1 [list {execsql { PRAGMA integrity_check } db2}] ok
+  db2 close
+
+  set cksum [scksum db main]
+  uplevel do_test $tn.2 [list {scksum db aux}] [list $cksum]
+}
+
+
+forcedelete test.db2
+do_execsql_test 1.0 {
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t2 VALUES(1, 'one');
+  INSERT INTO t2 VALUES(2, 'two');
+
+  ATTACH 'test.db2' AS aux;
+  CREATE TABLE aux.t2(a PRIMARY KEY, b);
+}
+
+do_test 1.1 {
+  sqlite3session S db main
+  S attach t2
+  S diff aux t2
+  set C [S changeset]
+  S delete
+} {}
+
+do_test 1.2 {
+  sqlite3 db2 test.db2
+  sqlite3changeset_apply db2 $C ""
+  db2 close
+  db eval { SELECT * FROM aux.t2 }
+} {1 one 2 two}
+
+do_diff_test 2.1 {
+  CREATE TABLE aux.t1(x, y, PRIMARY KEY(y));
+  CREATE TABLE t1(x, y, PRIMARY KEY(y));
+
+  INSERT INTO t1 VALUES(1, 2);
+  INSERT INTO t1 VALUES(NULL, 'xyz');
+  INSERT INTO t1 VALUES(4.5, 5.5);
+}
+
+do_diff_test 2.2 {
+  CREATE TABLE aux.t1(x, y, PRIMARY KEY(y));
+  CREATE TABLE t1(x, y, PRIMARY KEY(y));
+
+  INSERT INTO aux.t1 VALUES(1, 2);
+  INSERT INTO aux.t1 VALUES(NULL, 'xyz');
+  INSERT INTO aux.t1 VALUES(4.5, 5.5);
+}
+
+do_diff_test 2.3 {
+  CREATE TABLE aux.t1(a PRIMARY KEY, b TEXT);
+  CREATE TABLE t1(a PRIMARY KEY, b TEXT);
+
+  INSERT INTO aux.t1 VALUES(1, 'one');
+  INSERT INTO aux.t1 VALUES(2, 'two');
+  INSERT INTO aux.t1 VALUES(3, 'three');
+
+  INSERT INTO t1 VALUES(1, 'I');
+  INSERT INTO t1 VALUES(2, 'two');
+  INSERT INTO t1 VALUES(3, 'III');
+}
+
+do_diff_test 2.4 {
+  CREATE TABLE aux.t1(a, b, c, d, PRIMARY KEY(c, b, a));
+  CREATE TABLE t1(a, b, c, d, PRIMARY KEY(c, b, a));
+
+  INSERT INTO t1 VALUES('hvkzyipambwdqlvwv','',-458331.50,X'DA51ED5E84');
+  INSERT INTO t1 VALUES(X'C5C6B5DD','jjxrath',40917,830244);
+  INSERT INTO t1 VALUES(-204877.54,X'1704C253D5F3AFA8',155120.88,NULL);
+  INSERT INTO t1 
+  VALUES('ckmqmzoeuvxisxqy',X'EB5A5D3A1DD22FD1','tidhjcbvbppdt',-642987.37);
+  INSERT INTO t1 VALUES(-851726,-161992,-469943,-159541);
+  INSERT INTO t1 VALUES(X'4A6A667F858938',185083,X'7A',NULL);
+
+  INSERT INTO aux.t1 VALUES(415075.74,'auawczkb',X'',X'57B4FAAF2595');
+  INSERT INTO aux.t1 VALUES(727637,711560,-181340,'hphuo');
+  INSERT INTO aux.t1 
+  VALUES(-921322.81,662959,'lvlgwdgxaurr','ajjrzrbhqflsutnymgc');
+  INSERT INTO aux.t1 VALUES(-146061,-377892,X'4E','gepvpvvuhszpxabbb');
+  INSERT INTO aux.t1 VALUES(-851726,-161992,-469943,-159541);
+  INSERT INTO aux.t1 VALUES(X'4A6A667F858938',185083,X'7A',NULL);
+  INSERT INTO aux.t1 VALUES(-204877.54,X'1704C253D5F3AFA8',155120.88, 4);
+  INSERT INTO aux.t1 
+  VALUES('ckmqmzoeuvxisxqy',X'EB5A5D3A1DD22FD1','tidgtsplhjcbvbppdt',-642987.3);
+}
+
+finish_test
+

ext/session/session_common.tcl

@@ -0,0 +1,135 @@
+
+
+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 +1,587 @@
+# 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 $testdir/tester.tcl
+
+set testprefix sessionfault
+
+forcedelete test.db2
+sqlite3 db2 test.db2
+do_common_sql {
+  CREATE TABLE t1(a, b, c, PRIMARY KEY(a, b));
+  INSERT INTO t1 VALUES(1, 2, 3);
+  INSERT INTO t1 VALUES(4, 5, 6);
+}
+faultsim_save_and_close
+db2 close
+
+#-------------------------------------------------------------------------
+# Test OOM error handling when collecting and applying a simple changeset.
+#
+# Test 1.1 attaches tables individually by name to the session object. 
+# Whereas test 1.2 passes NULL to sqlite3session_attach() to attach all
+# tables.
+#
+do_faultsim_test 1.1 -faults oom-* -prep {
+  catch {db2 close}
+  catch {db close}
+  faultsim_restore_and_reopen
+  sqlite3 db2 test.db2
+} -body {
+  do_then_apply_sql {
+    INSERT INTO t1 VALUES('a string value', 8, 9);
+    UPDATE t1 SET c = 10 WHERE a = 1;
+    DELETE FROM t1 WHERE a = 4;
+  }
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  faultsim_integrity_check
+  if {$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 5.1 -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" }
+  }
+}
+
+catch {db close}
+catch {db2 close}
+forcedelete test.db
+sqlite3 db test.db
+execsql {
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t2 VALUES(1, 'abc');
+  INSERT INTO t2 VALUES(2, 'def');
+}
+set changeset [changeset_from_sql {
+  UPDATE t2 SET b = (b || b || b || b);
+  UPDATE t2 SET b = (b || b || b || b);
+  UPDATE t2 SET b = (b || b || b || b);
+  UPDATE t2 SET b = (b || b || b || b);
+}]
+db close
+set abc [string repeat abc 256]
+set def [string repeat def 256]
+
+do_faultsim_test 5.2 -faults oom-tra* -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 "
+        {UPDATE t2 0 X. {i 1 t $::abc} {{} {} t abc}}
+        {UPDATE t2 0 X. {i 2 t $::def} {{} {} t def}}
+    " { lappend y $c }
+    if {$x != $y} { error "changeset no good" }
+  }
+}
+
+catch {db close}
+catch {db2 close}
+forcedelete test.db
+sqlite3 db test.db
+set abc [string repeat abc 256]
+set def [string repeat def 256]
+execsql "
+  CREATE TABLE t2(a PRIMARY KEY, b);
+  INSERT INTO t2 VALUES(1, '$abc');
+"
+set changeset [changeset_from_sql "
+  INSERT INTO t2 VALUES(2, '$def');
+  DELETE FROM t2 WHERE a = 1;
+"]
+db close
+
+do_faultsim_test 5.3 -faults oom-tra* -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 "
+        {INSERT t2 0 X. {} {i 1 t $::abc}}
+        {DELETE t2 0 X. {i 2 t $::def} {}}
+    " { 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] != $expected } {
+      error "changeset mismatch"
+    }
+  }
+}
+
+#-------------------------------------------------------------------------
+# Test that if a conflict-handler encounters an OOM in 
+# sqlite3_value_text() but goes on to return SQLITE_CHANGESET_REPLACE
+# anyway, the OOM is picked up by the sessions module.
+set bigstr [string repeat abcdefghij 100]
+faultsim_delete_and_reopen
+do_test 10.prep.1  {
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    INSERT INTO t1 VALUES($bigstr, $bigstr);
+  }
+
+  sqlite3session S db main
+  S attach *
+  execsql { UPDATE t1 SET b = b||'x' }
+  set C [S changeset]
+  S delete
+  execsql { UPDATE t1 SET b = b||'xyz' }
+} {}
+faultsim_save_and_close
+
+faultsim_restore_and_reopen
+do_test 10.prep.2  {
+  proc xConflict {args} { return "ABORT" }
+  list [catch { sqlite3changeset_apply db $C xConflict } msg] $msg
+} {1 SQLITE_ABORT}
+do_execsql_test 10.prep.3 { SELECT b=$bigstr||'x' FROM t1 } 0
+do_test 10.prep.4  {
+  proc xConflict {args} { return "REPLACE" }
+  list [catch { sqlite3changeset_apply db $C xConflict } msg] $msg
+} {0 {}}
+do_execsql_test 10.prep.5 { SELECT b=$bigstr||'x' FROM t1 } 1
+db close
+
+do_faultsim_test 10 -faults oom-tra* -prep {
+  faultsim_restore_and_reopen
+} -body {
+  sqlite3changeset_apply_replace_all db $::C 
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} {
+    if {[db one {SELECT b=$bigstr||'x' FROM t1}]==0} {
+      error "data does not look right"
+    }
+  }
+}
+
+#-------------------------------------------------------------------------
+# Test an OOM with an sqlite3changeset_apply() filter callback.
+#
+reset_db
+do_test 11.prep {
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b);
+    CREATE TABLE t2(x PRIMARY KEY, y);
+    BEGIN;
+  }
+
+  set ::cs [changeset_from_sql { 
+    INSERT INTO t1 VALUES(1, 2);
+    INSERT INTO t2 VALUES('x', 'y');
+  }]
+
+  execsql ROLLBACK
+  set {} {}
+} {}
+
+proc filter {x} { return [string equal t1 $x] } 
+faultsim_save_and_close
+
+do_faultsim_test 11 -faults oom-tra* -prep {
+  faultsim_restore_and_reopen
+} -body {
+  sqlite3changeset_apply db $::cs {} filter
+} -test {
+  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
+  if {$testrc==0} {
+    if {[db eval {SELECT * FROM t1 UNION ALL SELECT * FROM t2}] != "1 2"} {
+      error "data does not look right"
+    }
+  }
+}
+
+
+finish_test

ext/session/test_session.c

@@ -0,0 +1,936 @@
+
+#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;
+};
+
+typedef struct TestStreamInput TestStreamInput;
+struct TestStreamInput {
+  int nStream;                    /* Maximum chunk size */
+  unsigned char *aData;           /* Pointer to buffer containing data */
+  int nData;                      /* Size of buffer aData in bytes */
+  int iData;                      /* Bytes of data already read by sessions */
+};
+
+#define SESSION_STREAM_TCL_VAR "sqlite3session_streams"
+
+/*
+** Attempt to find the global variable zVar within interpreter interp
+** and extract an integer value from it. Return this value.
+**
+** If the named variable cannot be found, or if it cannot be interpreted
+** as a integer, return 0.
+*/
+static int test_tcl_integer(Tcl_Interp *interp, const char *zVar){
+  Tcl_Obj *pObj;
+  int iVal = 0;
+  pObj = Tcl_ObjGetVar2(interp, Tcl_NewStringObj(zVar, -1), 0, TCL_GLOBAL_ONLY);
+  if( pObj ) Tcl_GetIntFromObj(0, pObj, &iVal);
+  return iVal;
+}
+
+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;
+}
+
+struct TestSessionsBlob {
+  void *p;
+  int n;
+};
+typedef struct TestSessionsBlob TestSessionsBlob;
+
+static int testStreamOutput(
+  void *pCtx,
+  const void *pData,
+  int nData
+){
+  TestSessionsBlob *pBlob = (TestSessionsBlob*)pCtx;
+  char *pNew;
+
+  assert( nData>0 );
+  pNew = (char*)sqlite3_realloc(pBlob->p, pBlob->n + nData);
+  if( pNew==0 ){
+    return SQLITE_NOMEM;
+  }
+  pBlob->p = (void*)pNew;
+  memcpy(&pNew[pBlob->n], pData, nData);
+  pBlob->n += nData;
+  return SQLITE_OK;
+}
+
+/*
+** Tclcmd:  $session attach TABLE
+**          $session changeset
+**          $session delete
+**          $session enable BOOL
+**          $session indirect INTEGER
+**          $session patchset
+**          $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 */
+    { "patchset",     0, "",           }, /* 7 */
+    { "diff",         2, "FROMDB TBL", }, /* 8 */
+    { 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 7:        /* patchset */
+    case 1: {      /* changeset */
+      TestSessionsBlob o = {0, 0};
+      if( test_tcl_integer(interp, SESSION_STREAM_TCL_VAR) ){
+        void *pCtx = (void*)&o;
+        if( iSub==7 ){
+          rc = sqlite3session_patchset_strm(pSession, testStreamOutput, pCtx);
+        }else{
+          rc = sqlite3session_changeset_strm(pSession, testStreamOutput, pCtx);
+        }
+      }else{
+        if( iSub==7 ){
+          rc = sqlite3session_patchset(pSession, &o.n, &o.p);
+        }else{
+          rc = sqlite3session_changeset(pSession, &o.n, &o.p);
+        }
+      }
+      if( rc==SQLITE_OK ){
+        Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(o.p, o.n)); 
+      }
+      sqlite3_free(o.p);
+      if( rc!=SQLITE_OK ){
+        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;
+    }
+
+    case 8: {      /* diff */
+      char *zErr = 0;
+      rc = sqlite3session_diff(pSession, 
+          Tcl_GetString(objv[2]),
+          Tcl_GetString(objv[3]),
+          &zErr
+      );
+      assert( rc!=SQLITE_OK || zErr==0 );
+      if( zErr ){
+        Tcl_AppendResult(interp, zErr, 0);
+        return TCL_ERROR;
+      }
+      if( rc ){
+        return test_session_error(interp, rc);
+      }
+      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 );
+    }
+    if( eConf!=SQLITE_CHANGESET_FOREIGN_KEY ){
+      /* eConf!=FOREIGN_KEY is always true at this point. The condition is 
+      ** just there to make it clearer what is being tested.  */
+      int nDummy;
+      int rc = sqlite3changeset_fk_conflicts(pIter, &nDummy);
+      assert( rc==SQLITE_MISUSE );
+    }
+    /* 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;
+}
+
+/*
+** The conflict handler used by sqlite3changeset_apply_replace_all(). 
+** This conflict handler calls sqlite3_value_text16() on all available
+** sqlite3_value objects and then returns CHANGESET_REPLACE, or 
+** CHANGESET_OMIT if REPLACE is not applicable. This is used to test the
+** effect of a malloc failure within an sqlite3_value_xxx() function
+** invoked by a conflict-handler callback.
+*/
+static int replace_handler(
+  void *pCtx,                     /* Pointer to TestConflictHandler structure */
+  int eConf,                      /* DATA, MISSING, CONFLICT, CONSTRAINT */
+  sqlite3_changeset_iter *pIter   /* Handle describing change and conflict */
+){
+  int op;                         /* SQLITE_UPDATE, DELETE or INSERT */
+  const char *zTab;               /* Name of table conflict is on */
+  int nCol;                       /* Number of columns in table zTab */
+  int i;
+  int x = 0;
+
+  sqlite3changeset_op(pIter, &zTab, &nCol, &op, 0);
+
+  if( op!=SQLITE_INSERT ){
+    for(i=0; i<nCol; i++){
+      sqlite3_value *pVal;
+      sqlite3changeset_old(pIter, i, &pVal);
+      sqlite3_value_text16(pVal);
+      x++;
+    }
+  }
+
+  if( op!=SQLITE_DELETE ){
+    for(i=0; i<nCol; i++){
+      sqlite3_value *pVal;
+      sqlite3changeset_new(pIter, i, &pVal);
+      sqlite3_value_text16(pVal);
+      x++;
+    }
+  }
+
+  if( eConf==SQLITE_CHANGESET_DATA ){
+    return SQLITE_CHANGESET_REPLACE;
+  }
+  return SQLITE_CHANGESET_OMIT;
+}
+
+static int testStreamInput(
+  void *pCtx,                     /* Context pointer */
+  void *pData,                    /* Buffer to populate */
+  int *pnData                     /* IN/OUT: Bytes requested/supplied */
+){
+  TestStreamInput *p = (TestStreamInput*)pCtx;
+  int nReq = *pnData;             /* Bytes of data requested */
+  int nRem = p->nData - p->iData; /* Bytes of data available */
+  int nRet = p->nStream;          /* Bytes actually returned */
+
+  /* Allocate and free some space. There is no point to this, other than
+  ** that it allows the regular OOM fault-injection tests to cause an error
+  ** in this function.  */
+  void *pAlloc = sqlite3_malloc(10);
+  if( pAlloc==0 ) return SQLITE_NOMEM;
+  sqlite3_free(pAlloc);
+
+  if( nRet>nReq ) nRet = nReq;
+  if( nRet>nRem ) nRet = nRem;
+
+  assert( nRet>=0 );
+  if( nRet>0 ){
+    memcpy(pData, &p->aData[p->iData], nRet);
+    p->iData += nRet;
+  }
+
+  *pnData = nRet;
+  return SQLITE_OK;
+}
+
+
+/*
+** 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;
+  TestStreamInput sStr;
+
+  memset(&sStr, 0, sizeof(sStr));
+  sStr.nStream = test_tcl_integer(interp, SESSION_STREAM_TCL_VAR);
+
+  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;
+
+  if( sStr.nStream==0 ){
+    rc = sqlite3changeset_apply(db, nChangeset, pChangeset, 
+        (objc==5) ? test_filter_handler : 0, test_conflict_handler, (void *)&ctx
+    );
+  }else{
+    sStr.aData = (unsigned char*)pChangeset;
+    sStr.nData = nChangeset;
+    rc = sqlite3changeset_apply_strm(db, testStreamInput, (void*)&sStr,
+        (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_apply_replace_all DB CHANGESET 
+*/
+static int test_sqlite3changeset_apply_replace_all(
+  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 */
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB CHANGESET");
+    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);
+
+  rc = sqlite3changeset_apply(db, nChangeset, pChangeset, 0, replace_handler,0);
+  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() */
+  TestStreamInput sIn;            /* Input stream */
+  TestSessionsBlob sOut;          /* Output blob */
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "CHANGESET");
+    return TCL_ERROR;
+  }
+
+  memset(&sIn, 0, sizeof(sIn));
+  memset(&sOut, 0, sizeof(sOut));
+  sIn.nStream = test_tcl_integer(interp, SESSION_STREAM_TCL_VAR);
+  sIn.aData = Tcl_GetByteArrayFromObj(objv[1], &sIn.nData);
+
+  if( sIn.nStream ){
+    rc = sqlite3changeset_invert_strm(
+        testStreamInput, (void*)&sIn, testStreamOutput, (void*)&sOut
+    );
+  }else{
+    rc = sqlite3changeset_invert(sIn.nData, sIn.aData, &sOut.n, &sOut.p);
+  }
+  if( rc!=SQLITE_OK ){
+    rc = test_session_error(interp, rc);
+  }else{
+    Tcl_SetObjResult(interp,Tcl_NewByteArrayObj((unsigned char*)sOut.p,sOut.n));
+  }
+  sqlite3_free(sOut.p);
+  return rc;
+}
+
+/*
+** 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() */
+
+  TestStreamInput sLeft;          /* Input stream */
+  TestStreamInput sRight;         /* Input stream */
+  TestSessionsBlob sOut = {0,0};  /* Output blob */
+
+  if( objc!=3 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "LEFT RIGHT");
+    return TCL_ERROR;
+  }
+
+  memset(&sLeft, 0, sizeof(sLeft));
+  memset(&sRight, 0, sizeof(sRight));
+  sLeft.aData = Tcl_GetByteArrayFromObj(objv[1], &sLeft.nData);
+  sRight.aData = Tcl_GetByteArrayFromObj(objv[2], &sRight.nData);
+  sLeft.nStream = test_tcl_integer(interp, SESSION_STREAM_TCL_VAR);
+  sRight.nStream = sLeft.nStream;
+
+  if( sLeft.nStream>0 ){
+    rc = sqlite3changeset_concat_strm(
+        testStreamInput, (void*)&sLeft,
+        testStreamInput, (void*)&sRight,
+        testStreamOutput, (void*)&sOut
+    );
+  }else{
+    rc = sqlite3changeset_concat(
+        sLeft.nData, sLeft.aData, sRight.nData, sRight.aData, &sOut.n, &sOut.p
+    );
+  }
+
+  if( rc!=SQLITE_OK ){
+    rc = test_session_error(interp, rc);
+  }else{
+    Tcl_SetObjResult(interp,Tcl_NewByteArrayObj((unsigned char*)sOut.p,sOut.n));
+  }
+  sqlite3_free(sOut.p);
+  return rc;
+}
+
+/*
+** 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;
+
+  TestStreamInput sStr;
+  memset(&sStr, 0, sizeof(sStr));
+
+  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);
+  sStr.nStream = test_tcl_integer(interp, SESSION_STREAM_TCL_VAR);
+  if( sStr.nStream==0 ){
+    rc = sqlite3changeset_start(&pIter, nChangeset, pChangeset);
+  }else{
+    sStr.aData = (unsigned char*)pChangeset;
+    sStr.nData = nChangeset;
+    rc = sqlite3changeset_start_strm(&pIter, testStreamInput, (void*)&sStr);
+  }
+  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;
+
+    /* Test that _fk_conflicts() returns SQLITE_MISUSE if called on this
+    ** iterator. */
+    int nDummy;
+    if( SQLITE_MISUSE!=sqlite3changeset_fk_conflicts(pIter, &nDummy) ){
+      sqlite3changeset_finalize(pIter);
+      return TCL_ERROR;
+    }
+
+    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
+  );
+  Tcl_CreateObjCommand(
+      interp, "sqlite3changeset_apply_replace_all", 
+      test_sqlite3changeset_apply_replace_all, 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$(TOP)/ext/async -I$(TOP)/ext/userauth
+TCCX += -I$(TOP)/ext/session
 
 # Object files for the SQLite library.
 #
@@ -71,6 +72,8 @@ LIBOBJ+= vdbe.o parse.o \
          vdbeapi.o vdbeaux.o vdbeblob.o vdbemem.o vdbesort.o \
 	 vdbetrace.o wal.o walker.o where.o utf.o vtab.o
 
+LIBOBJ += sqlite3session.o
+
 
 
 # All of the source code files.
@@ -217,6 +220,9 @@ SRC += \
   $(TOP)/ext/rtree/sqlite3rtree.h \
   $(TOP)/ext/rtree/rtree.h \
   $(TOP)/ext/rtree/rtree.c
+SRC += \
+  $(TOP)/ext/session/sqlite3session.c \
+  $(TOP)/ext/session/sqlite3session.h
 SRC += \
   $(TOP)/ext/userauth/userauth.c \
   $(TOP)/ext/userauth/sqlite3userauth.h
@@ -338,7 +344,9 @@ 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.
 #
@@ -442,6 +450,7 @@ 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
@@ -586,6 +595,9 @@ rtree.o:	$(TOP)/ext/rtree/rtree.c $(HDR) $(EXTHDR)
 userauth.o:	$(TOP)/ext/userauth/userauth.c $(HDR) $(EXTHDR)
 	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/userauth/userauth.c
 
+sqlite3session.o:	$(TOP)/ext/session/sqlite3session.c $(HDR) $(EXTHDR)
+	$(TCCX) -DSQLITE_CORE -c $(TOP)/ext/session/sqlite3session.c
+
 
 # Rules for building test programs and for running tests
 #
@@ -593,7 +605,8 @@ 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){" >> $@
@@ -614,9 +627,11 @@ testfixture$(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) $(TOP)/src/tclsqlite.c
@@ -680,6 +695,10 @@ showwal$(EXE):	$(TOP)/tool/showwal.c sqlite3.o
 	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o showwal$(EXE) \
 		$(TOP)/tool/showwal.c sqlite3.o $(THREADLIB)
 
+changeset$(EXE):	$(TOP)/ext/session/changeset.c sqlite3.o
+	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o changeset$(EXE) \
+		$(TOP)/ext/session/changeset.c sqlite3.o $(THREADLIB)
+
 fts3view$(EXE):	$(TOP)/ext/fts3/tool/fts3view.c sqlite3.o
 	$(TCC) -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION -o fts3view$(EXE) \
 		$(TOP)/ext/fts3/tool/fts3view.c sqlite3.o $(THREADLIB)
@@ -738,6 +757,7 @@ clean:
 	rm -f showjournal showjournal.exe
 	rm -f showstat4 showstat4.exe
 	rm -f showwal showwal.exe
+	rm -f changeset changeset.exe
 	rm -f speedtest1 speedtest1.exe
 	rm -f wordcount wordcount.exe
 	rm -f sqlite3.c sqlite3-*.c fts?amal.c tclsqlite3.c

manifest

@@ -1,9 +1,9 @@
-C Avoid\ssigned\sinteger\soverflow\swhen\sconverting\soversized\sin-line\sinteger\nwidths\sand\sprecisions\sin\sprintf().
-D 2015-04-07T15:39:29.937
+C Add\sexperimental\sAPI\ssqlite3session_diff().
+D 2015-04-08T16:01:12.482
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
-F Makefile.in 00d12636df7a5b08af09116bcd6c7bfd49b8b3b4
+F Makefile.in 3083cf0c2bc6618e532b9478ce735bb512322985
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
-F Makefile.msc a8d817fa486d8c88dfbd19ae6a6567d9d350de39
+F Makefile.msc ffb3a33f21fcc6f7d4b0cc76a981f62f17c62b24
 F Makefile.vxworks e1b65dea203f054e71653415bd8f96dcaed47858
 F README.md d58e3bebc0a4145e0f2a87994015fdb575a8e866
 F VERSION 319eb1ced4b4d17a67730f2b7b85f15c1346cb60
@@ -146,13 +146,31 @@ F ext/rtree/rtree_util.tcl 06aab2ed5b826545bf215fff90ecb9255a8647ea
 F ext/rtree/sqlite3rtree.h 83349d519fe5f518b3ea025d18dd1fe51b1684bd
 F ext/rtree/tkt3363.test 142ab96eded44a3615ec79fba98c7bde7d0f96de
 F ext/rtree/viewrtree.tcl eea6224b3553599ae665b239bd827e182b466024
+F ext/session/changeset.c 4ccbaa4531944c24584bf6a61ba3a39c62b6267a
+F ext/session/session1.test 4653867f32a98ce4bbb4a181aac6debe51ca4dfb
+F ext/session/session2.test a95a2d270b32638c1acba7cb9c81856712d469ac
+F ext/session/session3.test a7a9ce59b8d1e49e2cc23d81421ac485be0eea01
+F ext/session/session4.test a6ed685da7a5293c5d6f99855bcf41dbc352ca84
+F ext/session/session5.test 716bc6fafd625ce60dfa62ae128971628c1a1169
+F ext/session/session6.test 443789bc2fca12e4f7075cf692c60b8a2bea1a26
+F ext/session/session8.test 8e194b3f655d861ca36de5d4de53f702751bab3b
+F ext/session/session9.test 5409d90d8141881d08285ed1c2c0d8d10fb92069
+F ext/session/sessionA.test 1feeab0b8e03527f08f2f1defb442da25480138f
+F ext/session/sessionB.test 06961b7c3641151f5d23088250ecad132501113c
+F ext/session/sessionC.test 3982f8577b0744c5ce3aaef7cfeb5bd903f17fe4
+F ext/session/sessionD.test 95903bd6a23dadbda7e192f730dd7dedd2d369ef
+F ext/session/session_common.tcl 9de0451b6a47218fc16b9ed8876b6238a0a3d88d
+F ext/session/sessionfault.test bef044d0952c0d62c31c8d2400be72c8684545cc
+F ext/session/sqlite3session.c 3fcf2efe81c90602db76b1da33538895034eef66
+F ext/session/sqlite3session.h d9ebd8d4c5791aafdf18165575c7f2223c09279b
+F ext/session/test_session.c 037fc25340a918eb2195972fed439d7adf7b5db9
 F ext/userauth/sqlite3userauth.h 19cb6f0e31316d0ee4afdfb7a85ef9da3333a220
 F ext/userauth/user-auth.txt e6641021a9210364665fe625d067617d03f27b04
 F ext/userauth/userauth.c 5fa3bdb492f481bbc1709fc83c91ebd13460c69e
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
 F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
 F magic.txt 8273bf49ba3b0c8559cb2774495390c31fd61c60
-F main.mk 997eee18387a3e69394f2f948c9c6ccf079655a4
+F main.mk 3876195fb0d4a873f643a3ee8ae4dc29b7bbb96b
 F mkopcodec.awk c2ff431854d702cdd2d779c9c0d1f58fa16fa4ea
 F mkopcodeh.awk c6b3fa301db6ef7ac916b14c60868aeaec1337b5
 F mkso.sh fd21c06b063bb16a5d25deea1752c2da6ac3ed83
@@ -181,7 +199,7 @@ F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
 F src/complete.c 198a0066ba60ab06fc00fba1998d870a4d575463
 F src/ctime.c 98f89724adc891a1a4c655bee04e33e716e05887
 F src/date.c e4d50b3283696836ec1036b695ead9a19e37a5ac
-F src/delete.c 37964e6c1d73ff49cbea9ff690c9605fb15f600e
+F src/delete.c 5075d88557eb4e2a7fdb2b61a96142830d8589b8
 F src/expr.c d09dac67d53c78880ba31d56e8ba2be3a6490553
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c e0444b61bed271a76840cbe6182df93a9baa3f12
@@ -190,12 +208,12 @@ F src/global.c 4f77cadbc5427d00139ba43d0f3979804cbb700e
 F src/hash.c 4263fbc955f26c2e8cdc0cf214bc42435aa4e4f5
 F src/hash.h c8f3c31722cf3277d03713909761e152a5b81094
 F src/hwtime.h d32741c8f4df852c7d959236615444e2b1063b08
-F src/insert.c 5b9243a33726008cc4132897d2be371db12a13be
+F src/insert.c 4f6df86bbed2d7b59e4601730407876825dd7b71
 F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d
 F src/legacy.c ba1863ea58c4c840335a84ec276fc2b25e22bc4e
 F src/lempar.c 7274c97d24bb46631e504332ccd3bd1b37841770
 F src/loadext.c 86bd4e2fccd520b748cba52492ab60c4a770f660
-F src/main.c 40e333960d53f7d50ee8ce09d40431c87ea653f2
+F src/main.c 4eecdeb7b3f6be5aa336252f71208344b5edd196
 F src/malloc.c 6a370b83d54e4bbf6f94021221c2a311cff26a18
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c abe6ee469b6c5a35c7f22bfeb9c9bac664a1c987
@@ -231,15 +249,15 @@ F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c 41aa91af56d960e9414ce1d7c17cfb68e0d1c6cb
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
 F src/select.c c28c52e353287434fac8473e56ee4be848d12c9d
-F src/shell.c 84a1593bd86aaa14f4da8a8f9b16fbc239d262aa
-F src/sqlite.h.in 278602140d49575e8708e643161f4263e428a02a
+F src/shell.c c4d839ad62f4986891601a21ce629a760f226682
+F src/sqlite.h.in 64287a2b3432550264a743addbf4162a692fdd1c
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 17d487c3c91b0b8c584a32fbeb393f6f795eea7d
-F src/sqliteInt.h 107b02ed6c64162b653acc2368e982de529e14f6
+F src/sqliteInt.h 19c0a189e57a68ae1d971346cb9ac9383fe29692
 F src/sqliteLimit.h 216557999cb45f2e3578ed53ebefe228d779cb46
 F src/status.c f266ad8a2892d659b74f0f50cb6a88b6e7c12179
 F src/table.c e7a09215315a978057fb42c640f890160dbcc45e
-F src/tclsqlite.c fa72a7c5278662357c105ba7925c1d0972506ff9
+F src/tclsqlite.c 7ed2644b48685cba250eb71c7c298fedab6e221a
 F src/test1.c 90fbedce75330d48d99eadb7d5f4223e86969585
 F src/test2.c 577961fe48961b2f2e5c8b56ee50c3f459d3359d
 F src/test3.c 64d2afdd68feac1bb5e2ffb8226c8c639f798622
@@ -254,7 +272,7 @@ F src/test_autoext.c dea8a01a7153b9adc97bd26161e4226329546e12
 F src/test_backup.c 2e6e6a081870150f20c526a2e9d0d29cda47d803
 F src/test_blob.c 1f2e3e25255b731c4fcf15ee7990d06347cb6c09
 F src/test_btree.c 2e9978eca99a9a4bfa8cae949efb00886860a64f
-F src/test_config.c c2d3ff6c129d50183900c7eff14158ff7e9b3f03
+F src/test_config.c 5140cf3a0b766d177dfb9f8f2a3b00224ec3f5c8
 F src/test_demovfs.c 0de72c2c89551629f58486fde5734b7d90758852
 F src/test_devsym.c e7498904e72ba7491d142d5c83b476c4e76993bc
 F src/test_fs.c ced436e3d4b8e4681328409b8081051ce614e28f
@@ -289,17 +307,17 @@ F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 6bbcc9fe50c917864d48287b4792d46d6e873481
 F src/tokenize.c a8d270b06e5f709930f7b67cf70a847969cb5bf3
 F src/trigger.c 25571661fdeae8c7f975ff40ffec205520a3f92f
-F src/update.c 3c4ecc282accf12d39edb8d524cf089645e55a13
+F src/update.c d207deb7a031f698104bee879de0632b611e72dd
 F src/utf.c fc6b889ba0779b7722634cdeaa25f1930d93820c
 F src/util.c 98a7627ca48ad3265b6940915a1d08355eb3fc7e
 F src/vacuum.c 9460b9de7b2d4e34b0d374894aa6c8a0632be8ec
-F src/vdbe.c 86ae6f4774410868af41bd839b72b7081ff03e78
-F src/vdbe.h 6fc69d9c5e146302c56e163cb4b31d1ee64a18c3
-F src/vdbeInt.h 9cbaa84f53ddd2d09a0cf61a94337a3a035d08a0
-F src/vdbeapi.c 583d56b129dd27f12bed518270de9ebe521e6a75
-F src/vdbeaux.c 413dc496248ac18eb0c19e35e86bb1ffd47b8907
-F src/vdbeblob.c 4f2e8e075d238392df98c5e03a64342465b03f90
-F src/vdbemem.c c0dc81285b7571b0a31c40f17846fe2397ec1cd9
+F src/vdbe.c 503f4f9396e1109bc9ff0fa6ee01c58e12bc782b
+F src/vdbe.h b434bb75fbec973d18d49225a59833ae39ee2afc
+F src/vdbeInt.h 96e4303a96c6f983e36e1fe32657b2c547f5c8f1
+F src/vdbeapi.c d95f2bb43d01a91d93231cde181811b38182202e
+F src/vdbeaux.c 3f36b184dbb5ca87b30c7c616d7cef6eb9e74ed6
+F src/vdbeblob.c ab33f9b57cfce7dddb23853090186da614be4846
+F src/vdbemem.c 149e585645c3f3ef063f2b7251646388cfe3d47d
 F src/vdbesort.c 919717d7599fa31d343ec28bffd0f9e91a4ff5f6
 F src/vdbetrace.c 7e4222955e07dd707a2f360c0eb73452be1cb010
 F src/vtab.c 62d49237bd8f3be4863815a39387b0f9897fa5e1
@@ -509,7 +527,7 @@ F test/fkey2.test 1db212cda86b0d3ce72714001f7b6381c321341c
 F test/fkey3.test 76d475c80b84ee7a5d062e56ccb6ea68882e2b49
 F test/fkey4.test 86446017011273aad8f9a99c1a65019e7bd9ca9d
 F test/fkey5.test 56bcb5a6e8b725b17febc267fb041a6695e86853
-F test/fkey6.test abb59f866c1b44926fd02d1fdd217d831fe04f48
+F test/fkey6.test 6697550baa38505c9952eff130ab26a2d156c0cc
 F test/fkey7.test 72e915890ee4a005daaf3002cb208e8fe973ac13
 F test/fkey8.test 8f08203458321e6c19a263829de4cfc936274ab0
 F test/fkey_malloc.test 594a7ea1fbab553c036c70813cd8bd9407d63749
@@ -634,7 +652,7 @@ F test/fuzzer1.test d4c52aaf3ef923da293a2653cfab33d02f718a36
 F test/fuzzerfault.test 8792cd77fd5bce765b05d0c8e01b9edcf8af8536
 F test/genesis.tcl 1e2e2e8e5cc4058549a154ff1892fe5c9de19f98
 F test/hexlit.test f9ecde8145bfc2341573473256c74ae37a200497
-F test/hook.test 162d7cef7a2d2b04839fe14402934e6a1b79442f
+F test/hook.test aa41c095d26822b8a51aa4c82904a14347961be6
 F test/icu.test 70df4faca133254c042d02ae342c0a141f2663f4
 F test/imposter1.test c3f1db2d3db2c24611a6596a3fc0ffc14f1466c8
 F test/in.test 047c4671328e9032ab95666a67021adbbd36e98e
@@ -793,7 +811,7 @@ F test/pagesize.test 1dd51367e752e742f58e861e65ed7390603827a0
 F test/pcache.test b09104b03160aca0d968d99e8cd2c5b1921a993d
 F test/pcache2.test a83efe2dec0d392f814bfc998def1d1833942025
 F test/percentile.test 4243af26b8f3f4555abe166f723715a1f74c77ff
-F test/permutations.test f9cc1dd987986c9d4949211c7a4ed55ec9aecba1
+F test/permutations.test e5e9f708879336e10095ded8d61966007f4a2c5c
 F test/pragma.test ad99d05e411c7687302124be56f3b362204be041
 F test/pragma2.test f624a496a95ee878e81e59961eade66d5c00c028
 F test/pragma3.test 6f849ccffeee7e496d2f2b5e74152306c0b8757c
@@ -853,6 +871,7 @@ F test/selectE.test fc02a1eb04c8eb537091482644b7d778ae8759b7
 F test/selectF.test 21c94e6438f76537b72532fa9fd4710cdd455fc3
 F test/selectG.test e8600e379589e85e9fefd2fe4d44a4cdd63f6982
 F test/server1.test 46803bd3fe8b99b30dbc5ff38ffc756f5c13a118
+F test/session.test 78fa2365e93d3663a6e933f86e7afc395adf18be
 F test/shared.test 1da9dbad400cee0d93f252ccf76e1ae007a63746
 F test/shared2.test 03eb4a8d372e290107d34b6ce1809919a698e879
 F test/shared3.test fcd65cb11d189eff5f5c85cc4fad246fb0933108
@@ -911,11 +930,11 @@ F test/sysfault.test fa776e60bf46bdd3ae69f0b73e46ee3977a58ae6
 F test/table.test 06271d61eb13871490d38168433c1ef3dd82bb2a
 F test/tableapi.test 2674633fa95d80da917571ebdd759a14d9819126
 F test/tableopts.test dba698ba97251017b7c80d738c198d39ab747930
-F test/tclsqlite.test 7fb866443c7deceed22b63948ccd6f76b52ad054
+F test/tclsqlite.test 7179b4e0bf236ddf0bfa6bfaefa76fbe0a23c28a
 F test/tempdb.test 19d0f66e2e3eeffd68661a11c83ba5e6ace9128c
 F test/temptable.test d2c9b87a54147161bcd1822e30c1d1cd891e5b30
 F test/temptrigger.test 8ec228b0db5d7ebc4ee9b458fc28cb9e7873f5e1
-F test/tester.tcl ed77454e6c7b40eb501db7e79d1c6fbfd3eebbff
+F test/tester.tcl 655afed0715958ec50fd575549e6c4e57311ff18
 F test/thread001.test 9f22fd3525a307ff42a326b6bc7b0465be1745a5
 F test/thread002.test e630504f8a06c00bf8bbe68528774dd96aeb2e58
 F test/thread003.test ee4c9efc3b86a6a2767516a37bd64251272560a7
@@ -1215,8 +1234,8 @@ F tool/mkopts.tcl 66ac10d240cc6e86abd37dc908d50382f84ff46e
 F tool/mkpragmatab.tcl 94f196c9961e0ca3513e29f57125a3197808be2d
 F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
 F tool/mksqlite3c-noext.tcl 69bae8ce4aa52d2ff82d4a8a856bf283ec035b2e
-F tool/mksqlite3c.tcl 52a3352f7aa15f1db851e45ac3a5e2173d6fe93c
-F tool/mksqlite3h.tcl 44730d586c9031638cdd2eb443b801c0d2dbd9f8
+F tool/mksqlite3c.tcl ebbf1198e19d84b4c34cca077d8f727a06ff8a11
+F tool/mksqlite3h.tcl 96d92fcac21c6037d9db20c7cb2e06b534b550ac
 F tool/mksqlite3internalh.tcl eb994013e833359137eb53a55acdad0b5ae1049b
 F tool/mkvsix.tcl 52a4c613707ac34ae9c226e5ccc69cb948556105
 F tool/offsets.c fe4262fdfa378e8f5499a42136d17bf3b98f6091
@@ -1241,7 +1260,7 @@ 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/varint.c 5d94cb5003db9dbbcbcc5df08d66f16071aee003
 F tool/vdbe-compress.tcl 5926c71f9c12d2ab73ef35c29376e756eb68361c
@@ -1249,7 +1268,10 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 95625ef3adc3c408d67e70f877f390445fbb8292
-R 5875861747bb686954783d9ce4259b86
-U drh
-Z e5281cee406ead55e17262e5bdbb2163
+P aeca95ac77f6f320a916f7e3c5a7a588ef4a20c8
+R 5c3cbffcff665bc16c7e835a4d990399
+T *branch * sessions-diff
+T *sym-sessions-diff *
+T -sym-sessions *
+U dan
+Z b513e16008d3799dcac5a3d5f415d7d8

manifest.uuid

@@ -1 +1 @@
-8e4ac2ce24415926247961b00a62425ae85d6ffb
+c4340b2ea2115ad97dcac036f9034e132ab789e5

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 );
@@ -671,13 +678,18 @@ 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

@@ -1332,9 +1332,21 @@ 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;
@@ -1590,7 +1602,7 @@ 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);
 }
@@ -1978,7 +1990,7 @@ 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

@@ -1856,6 +1856,27 @@ 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/shell.c

@@ -504,6 +504,19 @@ static char *one_input_line(FILE *in, char *zPrior, int isContinuation){
   return zResult;
 }
 
+#if defined(SQLITE_ENABLE_SESSION)
+/*
+** State information for a single open session
+*/
+typedef struct OpenSession OpenSession;
+struct OpenSession {
+  char *zName;             /* Symbolic name for this session */
+  int nFilter;             /* Number of xFilter rejection GLOB patterns */
+  char **azFilter;         /* Array of xFilter rejection GLOB patterns */
+  sqlite3_session *p;      /* The open session */
+};
+#endif
+
 /*
 ** Shell output mode information from before ".explain on", 
 ** saved so that it can be restored by ".explain off"
@@ -553,6 +566,10 @@ struct ShellState {
   int *aiIndent;         /* Array of indents used in MODE_Explain */
   int nIndent;           /* Size of array aiIndent[] */
   int iIndent;           /* Index of current op in aiIndent[] */
+#if defined(SQLITE_ENABLE_SESSION)
+  int nSession;             /* Number of active sessions */
+  OpenSession aSession[4];  /* Array of sessions.  [0] is in focus. */
+#endif
 };
 
 /*
@@ -1822,6 +1839,9 @@ static char zHelp[] =
   "                         LIKE pattern TABLE.\n"
   ".separator COL ?ROW?   Change the column separator and optionally the row\n"
   "                         separator for both the output mode and .import\n"
+#if defined(SQLITE_ENABLE_SESSION)
+  ".session CMD ...       Create or control sessions\n"
+#endif
   ".shell CMD ARGS...     Run CMD ARGS... in a system shell\n"
   ".show                  Show the current values for various settings\n"
   ".stats on|off          Turn stats on or off\n"
@@ -1837,6 +1857,30 @@ static char zHelp[] =
   "                         Negative values right-justify\n"
 ;
 
+#if defined(SQLITE_ENABLE_SESSION)
+/*
+** Print help information for the ".sessions" command
+*/
+void session_help(ShellState *p){
+  fprintf(p->out,
+    ".session ?NAME? SUBCOMMAND ?ARGS...?\n"
+    "If ?NAME? is omitted, the first defined session is used.\n"
+    "Subcommands:\n"
+    "   attach TABLE             Attach TABLE\n"
+    "   changeset FILE           Write a changeset into FILE\n"
+    "   close                    Close one session\n"
+    "   enable ?BOOLEAN?         Set or query the enable bit\n"
+    "   filter GLOB...           Reject tables matching GLOBs\n" 
+    "   indirect ?BOOLEAN?       Mark or query the indirect status\n"
+    "   isempty                  Query whether the session is empty\n"
+    "   list                     List currently open session names\n"
+    "   open DB NAME             Open a new session on DB\n"
+    "   patchset FILE            Write a patchset into FILE\n"
+  );
+}
+#endif
+
+
 /* Forward reference */
 static int process_input(ShellState *p, FILE *in);
 /*
@@ -1900,6 +1944,51 @@ static void writefileFunc(
   sqlite3_result_int64(context, rc);
 }
 
+#if defined(SQLITE_ENABLE_SESSION)
+/*
+** Close a single OpenSession object and release all of its associated
+** resources.
+*/
+static void session_close(OpenSession *pSession){
+  int i;
+  sqlite3session_delete(pSession->p);
+  sqlite3_free(pSession->zName);
+  for(i=0; i<pSession->nFilter; i++){
+    sqlite3_free(pSession->azFilter[i]);
+  }
+  sqlite3_free(pSession->azFilter);
+  memset(pSession, 0, sizeof(OpenSession));
+}
+#endif
+
+/*
+** Close all OpenSession objects and release all assocaited resources.
+*/
+static void session_close_all(ShellState *p){
+#if defined(SQLITE_ENABLE_SESSION)
+  int i;
+  for(i=0; i<p->nSession; i++){
+    session_close(&p->aSession[i]);
+  }
+  p->nSession = 0;
+#endif
+}
+
+/*
+** Implementation of the xFilter function for an open session.  Omit
+** any tables named by ".session filter" but let all other table through.
+*/
+#if defined(SQLITE_ENABLE_SESSION)
+static int session_filter(void *pCtx, const char *zTab){
+  OpenSession *pSession = (OpenSession*)pCtx;
+  int i;
+  for(i=0; i<pSession->nFilter; i++){
+    if( sqlite3_strglob(pSession->azFilter[i], zTab)==0 ) return 0;
+  }
+  return 1;
+}
+#endif
+
 /*
 ** Make sure the database is open.  If it is not, then open it.  If
 ** the database fails to open, print an error message and exit.
@@ -3253,6 +3342,7 @@ static int do_meta_command(char *zLine, ShellState *p){
     }
     open_db(p, 1);
     if( p->db!=0 ){
+      session_close_all(p);
       sqlite3_close(savedDb);
       sqlite3_free(p->zFreeOnClose);
       p->zFreeOnClose = zNewFilename;
@@ -3493,7 +3583,6 @@ static int do_meta_command(char *zLine, ShellState *p){
     }
   }else
 
-
 #if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
   if( c=='s' && n==11 && strncmp(azArg[0], "selecttrace", n)==0 ){
     extern int sqlite3SelectTrace;
@@ -3501,6 +3590,198 @@ static int do_meta_command(char *zLine, ShellState *p){
   }else
 #endif
 
+#if defined(SQLITE_ENABLE_SESSION)
+  if( c=='s' && strncmp(azArg[0],"session",n)==0 && n>=3 ){
+    OpenSession *pSession = &p->aSession[0];
+    char **azCmd = &azArg[1];
+    int iSes = 0;
+    int nCmd = nArg - 1;
+    int i;
+    if( nArg<=1 ) goto session_syntax_error;
+    open_db(p, 0);
+    if( nArg>=3 ){
+      for(iSes=0; iSes<p->nSession; iSes++){
+        if( strcmp(p->aSession[iSes].zName, azArg[1])==0 ) break;
+      }
+      if( iSes<p->nSession ){
+        pSession = &p->aSession[iSes];
+        azCmd++;
+        nCmd--;
+      }else{
+        pSession = &p->aSession[0];
+        iSes = 0;
+      }
+    }
+
+    /* .session attach TABLE
+    ** Invoke the sqlite3session_attach() interface to attach a particular
+    ** table so that it is never filtered.
+    */
+    if( strcmp(azCmd[0],"attach")==0 ){
+      if( nCmd!=2 ) goto session_syntax_error;
+      if( pSession->p==0 ){
+        session_not_open:
+        fprintf(stderr, "ERROR: No sessions are open\n");
+      }else{
+        rc = sqlite3session_attach(pSession->p, azCmd[1]);
+        if( rc ){
+          fprintf(stderr, "ERROR: sqlite3session_attach() returns %d\n", rc);
+          rc = 0;
+        }
+      }
+    }else
+
+    /* .session changeset FILE
+    ** .session patchset FILE
+    ** Write a changeset or patchset into a file.  The file is overwritten.
+    */
+    if( strcmp(azCmd[0],"changeset")==0 || strcmp(azCmd[0],"patchset")==0 ){
+      FILE *out = 0;
+      if( nCmd!=2 ) goto session_syntax_error;
+      if( pSession->p==0 ) goto session_not_open;
+      out = fopen(azCmd[1], "wb");
+      if( out==0 ){
+        fprintf(stderr, "ERROR: cannot open \"%s\" for writing\n", azCmd[1]);
+      }else{
+        int szChng;
+        void *pChng;
+        if( azCmd[0][0]=='c' ){
+          rc = sqlite3session_changeset(pSession->p, &szChng, &pChng);
+        }else{
+          rc = sqlite3session_patchset(pSession->p, &szChng, &pChng);
+        }
+        if( rc ){
+          printf("Error: error code %d\n", rc);
+          rc = 0;
+        }
+        if( pChng 
+          && fwrite(pChng, szChng, 1, out)!=1 ){
+          fprintf(stderr, "ERROR: Failed to write entire %d-byte output\n",
+                  szChng);
+        }
+        sqlite3_free(pChng);
+        fclose(out);
+      }
+    }else
+
+    /* .session close
+    ** Close the identified session
+    */
+    if( strcmp(azCmd[0], "close")==0 ){
+      if( nCmd!=1 ) goto session_syntax_error;
+      if( p->nSession ){
+        session_close(pSession);
+        p->aSession[iSes] = p->aSession[--p->nSession];
+      }
+    }else
+
+    /* .session enable ?BOOLEAN?
+    ** Query or set the enable flag
+    */
+    if( strcmp(azCmd[0], "enable")==0 ){
+      int ii;
+      if( nCmd>2 ) goto session_syntax_error;
+      ii = nCmd==1 ? -1 : booleanValue(azCmd[1]);
+      if( p->nSession ){
+        ii = sqlite3session_enable(pSession->p, ii);
+        fprintf(p->out, "session %s enable flag = %d\n", pSession->zName, ii);
+      }
+    }else
+
+    /* .session filter GLOB ....
+    ** Set a list of GLOB patterns of table names to be excluded.
+    */
+    if( strcmp(azCmd[0], "filter")==0 ){
+      int ii, nByte;
+      if( nCmd<2 ) goto session_syntax_error;
+      if( p->nSession ){
+        for(ii=0; ii<pSession->nFilter; ii++){
+          sqlite3_free(pSession->azFilter[ii]);
+        }
+        sqlite3_free(pSession->azFilter);
+        nByte = sizeof(pSession->azFilter[0])*(nCmd-1);
+        pSession->azFilter = sqlite3_malloc( nByte );
+        if( pSession->azFilter==0 ){
+          fprintf(stderr, "Error: out or memory\n");
+          exit(1);
+        }
+        for(ii=1; ii<nCmd; ii++){
+          pSession->azFilter[ii-1] = sqlite3_mprintf("%s", azCmd[ii]); 
+        }
+        pSession->nFilter = ii-1;
+      }
+    }else
+
+    /* .session indirect ?BOOLEAN?
+    ** Query or set the indirect flag
+    */
+    if( strcmp(azCmd[0], "indirect")==0 ){
+      int ii;
+      if( nCmd>2 ) goto session_syntax_error;
+      ii = nCmd==1 ? -1 : booleanValue(azCmd[1]);
+      if( p->nSession ){
+        ii = sqlite3session_indirect(pSession->p, ii);
+        fprintf(p->out, "session %s indirect flag = %d\n", pSession->zName,ii);
+      }
+    }else
+
+    /* .session isempty
+    ** Determine if the session is empty
+    */
+    if( strcmp(azCmd[0], "isempty")==0 ){
+      int ii;
+      if( nCmd!=1 ) goto session_syntax_error;
+      if( p->nSession ){
+        ii = sqlite3session_isempty(pSession->p);
+        fprintf(p->out, "session %s isempty flag = %d\n", pSession->zName, ii);
+      }
+    }else
+
+    /* .session list
+    ** List all currently open sessions
+    */
+    if( strcmp(azCmd[0],"list")==0 ){
+      for(i=0; i<p->nSession; i++){
+        fprintf(p->out, "%d %s\n", i, p->aSession[i].zName);
+      }
+    }else
+
+    /* .session open DB NAME
+    ** Open a new session called NAME on the attached database DB.
+    ** DB is normally "main".
+    */
+    if( strcmp(azCmd[0],"open")==0 ){
+      char *zName;
+      if( nCmd!=3 ) goto session_syntax_error;
+      zName = azCmd[2];
+      if( zName[0]==0 ) goto session_syntax_error;
+      for(i=0; i<p->nSession; i++){
+        if( strcmp(p->aSession[i].zName,zName)==0 ){
+          fprintf(stderr, "Session \"%s\" already exists\n", zName);
+          goto meta_command_exit;
+        }
+      }
+      if( p->nSession>=ArraySize(p->aSession) ){
+        fprintf(stderr, "Maximum of %d sessions\n", ArraySize(p->aSession));
+        goto meta_command_exit;
+      }
+      pSession = &p->aSession[p->nSession];
+      rc = sqlite3session_create(p->db, azCmd[1], &pSession->p);
+      if( rc ){
+        fprintf(stderr, "Cannot open session: error code=%d\n", rc);
+        rc = 0;
+        goto meta_command_exit;
+      }
+      pSession->nFilter = 0;
+      sqlite3session_table_filter(pSession->p, session_filter, pSession);
+      p->nSession++;
+      pSession->zName = sqlite3_mprintf("%s", zName);
+    }else
+    /* If no command name matches, show a syntax error */
+    session_syntax_error:
+    session_help(p);
+  }else
+#endif
 
 #ifdef SQLITE_DEBUG
   /* Undocumented commands for internal testing.  Subject to change
@@ -4696,6 +4977,7 @@ int SQLITE_CDECL main(int argc, char **argv){
   }
   set_table_name(&data, 0);
   if( data.db ){
+    session_close_all(&data);
     sqlite3_close(data.db);
   }
   sqlite3_free(data.zFreeOnClose); 

src/sqlite.h.in

@@ -5064,8 +5064,8 @@ 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*, 
@@ -6535,7 +6535,7 @@ 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>
 **
@@ -7625,6 +7625,101 @@ SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus(
 SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
 
 
+/*
+** 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

@@ -875,6 +875,7 @@ 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;
@@ -1125,6 +1126,13 @@ 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;
@@ -2698,6 +2706,9 @@ 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_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */
@@ -2705,6 +2716,7 @@ struct AuthContext {
 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */
+#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

@@ -140,6 +140,7 @@ 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) */
@@ -518,6 +519,9 @@ 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);
   }
@@ -685,6 +689,42 @@ 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,
@@ -694,14 +734,18 @@ 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));
@@ -1613,6 +1657,46 @@ 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
@@ -1638,11 +1722,12 @@ 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,
@@ -1652,11 +1737,11 @@ 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 */
 
@@ -2852,6 +2937,90 @@ 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?
   **    $db update_hook ?script?
@@ -2860,42 +3029,19 @@ static int DbObjCmd(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
   case DB_WAL_HOOK: 
   case DB_UPDATE_HOOK: 
   case DB_ROLLBACK_HOOK: {
-
     /* set ppHook to point at pUpdateHook or pRollbackHook, depending on 
     ** whether [$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;
   }
 
@@ -3771,6 +3917,9 @@ 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);
@@ -3814,6 +3963,9 @@ 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

@@ -131,6 +131,12 @@ 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
@@ -479,6 +485,12 @@ 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/update.c

@@ -584,10 +584,23 @@ 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
@@ -2798,7 +2808,7 @@ case OP_Savepoint: {
         }else{
           db->nSavepoint++;
         }
-    
+
         /* Link the new savepoint into the database handle's list. */
         pNew->pNext = db->pSavepoint;
         db->pSavepoint = pNew;
@@ -4119,9 +4129,9 @@ 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
@@ -4147,8 +4157,8 @@ 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 );
@@ -4158,6 +4168,7 @@ 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 ){
@@ -4171,6 +4182,25 @@ 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)
+   && 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 ){
@@ -4193,18 +4223,13 @@ 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.
 **
@@ -4219,14 +4244,24 @@ 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: {
   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 );
@@ -4234,26 +4269,51 @@ case OP_Delete: {
   assert( pC->deferredMoveto==0 );
 
 #ifdef SQLITE_DEBUG
-  /* The seek operation that positioned the cursor prior to OP_Delete will
-  ** have also set the pC->movetoTarget field to the rowid of the row that
-  ** is being deleted */
-  if( pOp->p4.z && pC->isTable ){
+  if( pOp->p4type==P4_TABLE && HasRowid(pOp->p4.pTab) ){
+    /* The seek operation that positioned the cursor prior to OP_Delete will
+    ** have also set the pC->movetoTarget field to the rowid of the row that
+    ** is being deleted */
     i64 iKey = 0;
     sqlite3BtreeKeySize(pC->pCursor, &iKey);
-    assert( pC->movetoTarget==iKey ); 
+    assert( pC->movetoTarget==iKey );
   }
 #endif
+
+  /* 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 );
+    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, pC->movetoTarget,
+        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, pC->movetoTarget);
-    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,
+                          pC->movetoTarget);
+    }
   }
-  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

@@ -388,6 +388,25 @@ 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
 */
@@ -447,6 +466,8 @@ int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
 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 *, int, VdbeCursor *);

src/vdbeapi.c

@@ -1508,6 +1508,187 @@ int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
   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);
+  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);
+  return sqlite3ApiExit(db, rc);
+}
+#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */
+
 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
 /*
 ** Return status data for a single loop within query pStmt.

src/vdbeaux.c

@@ -66,6 +66,7 @@ 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;
@@ -3237,6 +3238,7 @@ void sqlite3VdbeRecordUnpack(
     pMem->db = pKeyInfo->db;
     /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
     pMem->szMalloc = 0;
+    pMem->z = 0;
     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
     pMem++;
     if( (++u)>=p->nField ) break;
@@ -4183,3 +4185,85 @@ 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 */
 };
 
 
@@ -205,6 +207,8 @@ 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++) {
@@ -392,6 +396,30 @@ 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 ){

src/vdbemem.c

@@ -799,7 +799,6 @@ void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
 int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
   int rc = SQLITE_OK;
 
-  assert( pTo->db==pFrom->db );
   assert( (pFrom->flags & MEM_RowSet)==0 );
   if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);

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
@@ -196,10 +197,13 @@ 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 {
     INSERT INTO t1w VALUES(4, 'four');
+PRAGMA vdbe_debug=on;
+PRAGMA vdbe_addoptrace=on;
     DELETE FROM t1w WHERE b = 'two';
     UPDATE t1w SET b = '' WHERE a = 1 OR a = 3;
     DELETE FROM t1w WHERE 1; -- Avoid the truncate optimization (for now)
@@ -438,4 +442,413 @@ 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';
+}
+
+ifcapable !session {
+  # 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 {
@@ -939,6 +942,26 @@ 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 "session_strm" -description {
+  All session module related tests using the streaming APIs.
+} -files [
+  glob -nocomplain $::testdir/../ext/session/*.test
+] -dbconfig {
+  set ::sqlite3session_streams 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 +1,22 @@
+# 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
+  run_test_suite session_strm
+}
+
+finish_test

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

@@ -109,6 +109,7 @@ foreach hdr {
    pcache.h
    pragma.h
    rtree.h
+   sqlite3session.h
    sqlite3ext.h
    sqlite3.h
    sqliteicu.h
@@ -123,6 +124,7 @@ foreach hdr {
   set available_hdr($hdr) 1
 }
 set available_hdr(sqliteInt.h) 0
+set available_hdr(sqlite3session.h) 0
 
 # These headers should be copied into the amalgamation without modifying any
 # of their function declarations or definitions.
@@ -212,7 +214,7 @@ proc copy_file {filename} {
         regsub {^SQLITE_API } $line {} line
         # 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]} {
           set line SQLITE_API
           append line " " [string trim $rettype]
           if {[string index $rettype end] ne "*"} {
@@ -366,6 +368,8 @@ foreach file {
    rtree.c
    icu.c
    fts3_icu.c
+
+   sqlite3session.c
 } {
   copy_file tsrc/$file
 }

tool/mksqlite3h.tcl

@@ -71,6 +71,7 @@ fconfigure stdout -translation lf
 set filelist [subst {
   $TOP/src/sqlite.h.in
   $TOP/ext/rtree/sqlite3rtree.h
+  $TOP/ext/session/sqlite3session.h
 }]
 
 # These are the functions that accept a variable number of arguments.  They
@@ -90,6 +91,9 @@ set cdecllist {
 #
 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]
@@ -123,4 +127,7 @@ 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