Merge all recent enhancements and fixes from trunk.

FossilOrigin-Name: 199bfb67fdf642cca6cd5d460fa4dc602b94837a

19 files changed, 241 insertions, 120 deletions

diff --git a/src/btree.c b/src/btree.c
index 53e0ebbfc..eab5b9842 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1441,7 +1441,7 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
   
     /* At this point:
     **    iFreeBlk:   First freeblock after iStart, or zero if none
-    **    iPtr:       The address of a pointer iFreeBlk
+    **    iPtr:       The address of a pointer to iFreeBlk
     **
     ** Check to see if iFreeBlk should be coalesced onto the end of iStart.
     */
@@ -1449,6 +1449,7 @@ static int freeSpace(MemPage *pPage, u16 iStart, u16 iSize){
       nFrag = iFreeBlk - iEnd;
       if( iEnd>iFreeBlk ) return SQLITE_CORRUPT_BKPT;
       iEnd = iFreeBlk + get2byte(&data[iFreeBlk+2]);
+      if( iEnd > pPage->pBt->usableSize ) return SQLITE_CORRUPT_BKPT;
       iSize = iEnd - iStart;
       iFreeBlk = get2byte(&data[iFreeBlk]);
     }
@@ -3984,13 +3985,6 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
 **
 ** BtCursor.info is a cache of the information in the current cell.
 ** Using this cache reduces the number of calls to btreeParseCell().
-**
-** 2007-06-25:  There is a bug in some versions of MSVC that cause the
-** compiler to crash when getCellInfo() is implemented as a macro.
-** But there is a measureable speed advantage to using the macro on gcc
-** (when less compiler optimizations like -Os or -O0 are used and the
-** compiler is not doing aggressive inlining.)  So we use a real function
-** for MSVC and a macro for everything else.  Ticket #2457.
 */
 #ifndef NDEBUG
   static void assertCellInfo(BtCursor *pCur){
@@ -4003,28 +3997,15 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
 #else
   #define assertCellInfo(x)
 #endif
-#ifdef _MSC_VER
-  /* Use a real function in MSVC to work around bugs in that compiler. */
-  static void getCellInfo(BtCursor *pCur){
-    if( pCur->info.nSize==0 ){
-      int iPage = pCur->iPage;
-      btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
-      pCur->curFlags |= BTCF_ValidNKey;
-    }else{
-      assertCellInfo(pCur);
-    }
-  }
-#else /* if not _MSC_VER */
-  /* Use a macro in all other compilers so that the function is inlined */
-#define getCellInfo(pCur)                                                      \
-  if( pCur->info.nSize==0 ){                                                   \
-    int iPage = pCur->iPage;                                                   \
-    btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);        \
-    pCur->curFlags |= BTCF_ValidNKey;                                          \
-  }else{                                                                       \
-    assertCellInfo(pCur);                                                      \
+static SQLITE_NOINLINE void getCellInfo(BtCursor *pCur){
+  if( pCur->info.nSize==0 ){
+    int iPage = pCur->iPage;
+    pCur->curFlags |= BTCF_ValidNKey;
+    btreeParseCell(pCur->apPage[iPage],pCur->aiIdx[iPage],&pCur->info);
+  }else{
+    assertCellInfo(pCur);
   }
-#endif /* _MSC_VER */
+}
 
 #ifndef NDEBUG  /* The next routine used only within assert() statements */
 /*
diff --git a/src/build.c b/src/build.c
index 8c62fd18d..293680536 100644
--- a/src/build.c
+++ b/src/build.c
@@ -976,7 +976,7 @@ void sqlite3StartTable(
     int j1;
     int fileFormat;
     int reg1, reg2, reg3;
-    sqlite3BeginWriteOperation(pParse, 0, iDb);
+    sqlite3BeginWriteOperation(pParse, 1, iDb);
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     if( isVirtual ){
@@ -1924,6 +1924,7 @@ void sqlite3EndTable(
       regRec = ++pParse->nMem;
       regRowid = ++pParse->nMem;
       assert(pParse->nTab==1);
+      sqlite3MayAbort(pParse);
       sqlite3VdbeAddOp3(v, OP_OpenWrite, 1, pParse->regRoot, iDb);
       sqlite3VdbeChangeP5(v, OPFLAG_P2ISREG);
       pParse->nTab = 2;
diff --git a/src/expr.c b/src/expr.c
index 06993e737..ddf939d3f 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2208,17 +2208,6 @@ static void sqlite3ExprCodeIN(
 }
 #endif /* SQLITE_OMIT_SUBQUERY */
 
-/*
-** Duplicate an 8-byte value
-*/
-static char *dup8bytes(Vdbe *v, const char *in){
-  char *out = sqlite3DbMallocRaw(sqlite3VdbeDb(v), 8);
-  if( out ){
-    memcpy(out, in, 8);
-  }
-  return out;
-}
-
 #ifndef SQLITE_OMIT_FLOATING_POINT
 /*
 ** Generate an instruction that will put the floating point
@@ -2231,12 +2220,10 @@ static char *dup8bytes(Vdbe *v, const char *in){
 static void codeReal(Vdbe *v, const char *z, int negateFlag, int iMem){
   if( ALWAYS(z!=0) ){
     double value;
-    char *zV;
     sqlite3AtoF(z, &value, sqlite3Strlen30(z), SQLITE_UTF8);
     assert( !sqlite3IsNaN(value) ); /* The new AtoF never returns NaN */
     if( negateFlag ) value = -value;
-    zV = dup8bytes(v, (char*)&value);
-    sqlite3VdbeAddOp4(v, OP_Real, 0, iMem, 0, zV, P4_REAL);
+    sqlite3VdbeAddOp4Dup8(v, OP_Real, 0, iMem, 0, (u8*)&value, P4_REAL);
   }
 }
 #endif
@@ -2262,10 +2249,8 @@ static void codeInteger(Parse *pParse, Expr *pExpr, int negFlag, int iMem){
     assert( z!=0 );
     c = sqlite3DecOrHexToI64(z, &value);
     if( c==0 || (c==2 && negFlag) ){
-      char *zV;
       if( negFlag ){ value = c==2 ? SMALLEST_INT64 : -value; }
-      zV = dup8bytes(v, (char*)&value);
-      sqlite3VdbeAddOp4(v, OP_Int64, 0, iMem, 0, zV, P4_INT64);
+      sqlite3VdbeAddOp4Dup8(v, OP_Int64, 0, iMem, 0, (u8*)&value, P4_INT64);
     }else{
 #ifdef SQLITE_OMIT_FLOATING_POINT
       sqlite3ErrorMsg(pParse, "oversized integer: %s%s", negFlag ? "-" : "", z);
diff --git a/src/func.c b/src/func.c
index 62abf13d4..d0565357d 100644
--- a/src/func.c
+++ b/src/func.c
@@ -575,17 +575,15 @@ struct compareInfo {
 
 /*
 ** For LIKE and GLOB matching on EBCDIC machines, assume that every
-** character is exactly one byte in size.  Also, all characters are
-** able to participate in upper-case-to-lower-case mappings in EBCDIC
-** whereas only characters less than 0x80 do in ASCII.
+** character is exactly one byte in size.  Also, provde the Utf8Read()
+** macro for fast reading of the next character in the common case where
+** the next character is ASCII.
 */
 #if defined(SQLITE_EBCDIC)
 # define sqlite3Utf8Read(A)        (*((*A)++))
-# define GlobUpperToLower(A)       A = sqlite3UpperToLower[A]
-# define GlobUpperToLowerAscii(A)  A = sqlite3UpperToLower[A]
+# define Utf8Read(A)               (*(A++))
 #else
-# define GlobUpperToLower(A)       if( A<=0x7f ){ A = sqlite3UpperToLower[A]; }
-# define GlobUpperToLowerAscii(A)  A = sqlite3UpperToLower[A]
+# define Utf8Read(A)               (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))
 #endif
 
 static const struct compareInfo globInfo = { '*', '?', '[', 0 };
@@ -627,7 +625,7 @@ static const struct compareInfo likeInfoAlt = { '%', '_',   0, 0 };
 **      Ec        Where E is the "esc" character and c is any other
 **                character, including '%', '_', and esc, match exactly c.
 **
-** The comments through this routine usually assume glob matching.
+** The comments within this routine usually assume glob matching.
 **
 ** This routine is usually quick, but can be N**2 in the worst case.
 */
@@ -651,13 +649,12 @@ static int patternCompare(
   */
   matchOther = esc ? esc : pInfo->matchSet;
 
-  while( (c = sqlite3Utf8Read(&zPattern))!=0 ){
+  while( (c = Utf8Read(zPattern))!=0 ){
     if( c==matchAll ){  /* Match "*" */
       /* Skip over multiple "*" characters in the pattern.  If there
       ** are also "?" characters, skip those as well, but consume a
       ** single character of the input string for each "?" skipped */
-      while( (c=sqlite3Utf8Read(&zPattern)) == matchAll
-               || c == matchOne ){
+      while( (c=Utf8Read(zPattern)) == matchAll || c == matchOne ){
         if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){
           return 0;
         }
@@ -702,7 +699,7 @@ static int patternCompare(
           if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
         }
       }else{
-        while( (c2 = sqlite3Utf8Read(&zString))!=0 ){
+        while( (c2 = Utf8Read(zString))!=0 ){
           if( c2!=c ) continue;
           if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
         }
@@ -748,7 +745,7 @@ static int patternCompare(
         continue;
       }
     }
-    c2 = sqlite3Utf8Read(&zString);
+    c2 = Utf8Read(zString);
     if( c==c2 ) continue;
     if( noCase && c<0x80 && c2<0x80 && sqlite3Tolower(c)==sqlite3Tolower(c2) ){
       continue;
diff --git a/src/loadext.c b/src/loadext.c
index 5a2b9d297..dcdbb2812 100644
--- a/src/loadext.c
+++ b/src/loadext.c
@@ -402,7 +402,10 @@ static const sqlite3_api_routines sqlite3Apis = {
   sqlite3_reset_auto_extension,
   sqlite3_result_blob64,
   sqlite3_result_text64,
-  sqlite3_strglob
+  sqlite3_strglob,
+  /* Version 3.8.11 and later */
+  (sqlite3_value*(*)(const sqlite3_value*))sqlite3_value_dup,
+  sqlite3_value_free
 };
 
 /*
diff --git a/src/main.c b/src/main.c
index e0de69e75..20e09cf1f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2103,9 +2103,11 @@ int sqlite3TempInMemory(const sqlite3 *db){
   return ( db->temp_store!=1 );
 #endif
 #if SQLITE_TEMP_STORE==3
+  UNUSED_PARAMETER(db);
   return 1;
 #endif
 #if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
+  UNUSED_PARAMETER(db);
   return 0;
 #endif
 }
@@ -3377,7 +3379,9 @@ int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
 */
 int sqlite3_test_control(int op, ...){
   int rc = 0;
-#ifndef SQLITE_OMIT_BUILTIN_TEST
+#ifdef SQLITE_OMIT_BUILTIN_TEST
+  UNUSED_PARAMETER(op);
+#else
   va_list ap;
   va_start(ap, op);
   switch( op ){
diff --git a/src/mutex.c b/src/mutex.c
index 2b4503628..64efd3b05 100644
--- a/src/mutex.c
+++ b/src/mutex.c
@@ -45,9 +45,14 @@ int sqlite3MutexInit(void){
     }else{
       pFrom = sqlite3NoopMutex();
     }
-    memcpy(pTo, pFrom, offsetof(sqlite3_mutex_methods, xMutexAlloc));
-    memcpy(&pTo->xMutexFree, &pFrom->xMutexFree,
-           sizeof(*pTo) - offsetof(sqlite3_mutex_methods, xMutexFree));
+    pTo->xMutexInit = pFrom->xMutexInit;
+    pTo->xMutexEnd = pFrom->xMutexEnd;
+    pTo->xMutexFree = pFrom->xMutexFree;
+    pTo->xMutexEnter = pFrom->xMutexEnter;
+    pTo->xMutexTry = pFrom->xMutexTry;
+    pTo->xMutexLeave = pFrom->xMutexLeave;
+    pTo->xMutexHeld = pFrom->xMutexHeld;
+    pTo->xMutexNotheld = pFrom->xMutexNotheld;
     pTo->xMutexAlloc = pFrom->xMutexAlloc;
   }
   rc = sqlite3GlobalConfig.mutex.xMutexInit();
diff --git a/src/pcache1.c b/src/pcache1.c
index a8755a314..c394ff178 100644
--- a/src/pcache1.c
+++ b/src/pcache1.c
@@ -148,8 +148,15 @@ static SQLITE_WSD struct PCacheGlobal {
 /*
 ** Macros to enter and leave the PCache LRU mutex.
 */
-#define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
-#define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)
+#if !defined(SQLITE_ENABLE_MEMORY_MANAGEMENT) || SQLITE_THREADSAFE==0
+# define pcache1EnterMutex(X)  assert((X)->mutex==0)
+# define pcache1LeaveMutex(X)  assert((X)->mutex==0)
+# define PCACHE1_MIGHT_USE_GROUP_MUTEX 0
+#else
+# define pcache1EnterMutex(X) sqlite3_mutex_enter((X)->mutex)
+# define pcache1LeaveMutex(X) sqlite3_mutex_leave((X)->mutex)
+# define PCACHE1_MIGHT_USE_GROUP_MUTEX 1
+#endif
 
 /******************************************************************************/
 /******** Page Allocation/SQLITE_CONFIG_PCACHE Related Functions **************/
@@ -425,31 +432,30 @@ static void pcache1ResizeHash(PCache1 *p){
 **
 ** The PGroup mutex must be held when this function is called.
 */
-static void pcache1PinPage(PgHdr1 *pPage){
+static PgHdr1 *pcache1PinPage(PgHdr1 *pPage){
   PCache1 *pCache;
-  PGroup *pGroup;
 
   assert( pPage!=0 );
   assert( pPage->isPinned==0 );
   pCache = pPage->pCache;
-  pGroup = pCache->pGroup;
-  assert( pPage->pLruNext || pPage==pGroup->pLruTail );
-  assert( pPage->pLruPrev || pPage==pGroup->pLruHead );
-  assert( sqlite3_mutex_held(pGroup->mutex) );
+  assert( pPage->pLruNext || pPage==pCache->pGroup->pLruTail );
+  assert( pPage->pLruPrev || pPage==pCache->pGroup->pLruHead );
+  assert( sqlite3_mutex_held(pCache->pGroup->mutex) );
   if( pPage->pLruPrev ){
     pPage->pLruPrev->pLruNext = pPage->pLruNext;
   }else{
-    pGroup->pLruHead = pPage->pLruNext;
+    pCache->pGroup->pLruHead = pPage->pLruNext;
   }
   if( pPage->pLruNext ){
     pPage->pLruNext->pLruPrev = pPage->pLruPrev;
   }else{
-    pGroup->pLruTail = pPage->pLruPrev;
+    pCache->pGroup->pLruTail = pPage->pLruPrev;
   }
   pPage->pLruNext = 0;
   pPage->pLruPrev = 0;
   pPage->isPinned = 1;
   pCache->nRecyclable--;
+  return pPage;
 }
 
 
@@ -530,10 +536,12 @@ static int pcache1Init(void *NotUsed){
   UNUSED_PARAMETER(NotUsed);
   assert( pcache1.isInit==0 );
   memset(&pcache1, 0, sizeof(pcache1));
+#if SQLITE_THREADSAFE
   if( sqlite3GlobalConfig.bCoreMutex ){
     pcache1.grp.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_LRU);
     pcache1.mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_PMEM);
   }
+#endif
   pcache1.grp.mxPinned = 10;
   pcache1.isInit = 1;
   return SQLITE_OK;
@@ -729,9 +737,9 @@ static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
   ** attempt to allocate a new one. 
   */
   if( !pPage ){
-    if( createFlag==1 ) sqlite3BeginBenignMalloc();
+    if( createFlag==1 ){ sqlite3BeginBenignMalloc(); }
     pPage = pcache1AllocPage(pCache);
-    if( createFlag==1 ) sqlite3EndBenignMalloc();
+    if( createFlag==1 ){ sqlite3EndBenignMalloc(); }
   }
 
   if( pPage ){
@@ -805,8 +813,13 @@ static SQLITE_NOINLINE PgHdr1 *pcache1FetchStage2(
 **      proceed to step 5. 
 **
 **   5. Otherwise, allocate and return a new page buffer.
+**
+** There are two versions of this routine.  pcache1FetchWithMutex() is
+** the general case.  pcache1FetchNoMutex() is a faster implementation for
+** the common case where pGroup->mutex is NULL.  The pcache1Fetch() wrapper
+** invokes the appropriate routine.
 */
-static sqlite3_pcache_page *pcache1Fetch(
+static PgHdr1 *pcache1FetchNoMutex(
   sqlite3_pcache *p, 
   unsigned int iKey, 
   int createFlag
@@ -814,28 +827,63 @@ static sqlite3_pcache_page *pcache1Fetch(
   PCache1 *pCache = (PCache1 *)p;
   PgHdr1 *pPage = 0;
 
-  assert( offsetof(PgHdr1,page)==0 );
-  assert( pCache->bPurgeable || createFlag!=1 );
-  assert( pCache->bPurgeable || pCache->nMin==0 );
-  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
-  assert( pCache->nMin==0 || pCache->bPurgeable );
-  assert( pCache->nHash>0 );
-  pcache1EnterMutex(pCache->pGroup);
-
   /* Step 1: Search the hash table for an existing entry. */
   pPage = pCache->apHash[iKey % pCache->nHash];
   while( pPage && pPage->iKey!=iKey ){ pPage = pPage->pNext; }
 
   /* Step 2: Abort if no existing page is found and createFlag is 0 */
   if( pPage ){
-    if( !pPage->isPinned ) pcache1PinPage(pPage);
+    if( !pPage->isPinned ){
+      return pcache1PinPage(pPage);
+    }else{
+      return pPage;
+    }
   }else if( createFlag ){
     /* Steps 3, 4, and 5 implemented by this subroutine */
-    pPage = pcache1FetchStage2(pCache, iKey, createFlag);
+    return pcache1FetchStage2(pCache, iKey, createFlag);
+  }else{
+    return 0;
   }
+}
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX
+static PgHdr1 *pcache1FetchWithMutex(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
+  PCache1 *pCache = (PCache1 *)p;
+  PgHdr1 *pPage;
+
+  pcache1EnterMutex(pCache->pGroup);
+  pPage = pcache1FetchNoMutex(p, iKey, createFlag);
   assert( pPage==0 || pCache->iMaxKey>=iKey );
   pcache1LeaveMutex(pCache->pGroup);
-  return (sqlite3_pcache_page*)pPage;
+  return pPage;
+}
+#endif
+static sqlite3_pcache_page *pcache1Fetch(
+  sqlite3_pcache *p, 
+  unsigned int iKey, 
+  int createFlag
+){
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX || defined(SQLITE_DEBUG)
+  PCache1 *pCache = (PCache1 *)p;
+#endif
+
+  assert( offsetof(PgHdr1,page)==0 );
+  assert( pCache->bPurgeable || createFlag!=1 );
+  assert( pCache->bPurgeable || pCache->nMin==0 );
+  assert( pCache->bPurgeable==0 || pCache->nMin==10 );
+  assert( pCache->nMin==0 || pCache->bPurgeable );
+  assert( pCache->nHash>0 );
+#if PCACHE1_MIGHT_USE_GROUP_MUTEX
+  if( pCache->pGroup->mutex ){
+    return (sqlite3_pcache_page*)pcache1FetchWithMutex(p, iKey, createFlag);
+  }else
+#endif
+  {
+    return (sqlite3_pcache_page*)pcache1FetchNoMutex(p, iKey, createFlag);
+  }
 }
 
 
diff --git a/src/shell.c b/src/shell.c
index c6317e99f..746e7229b 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -1348,7 +1348,10 @@ static void display_scanstats(
   sqlite3 *db,                    /* Database to query */
   ShellState *pArg                /* Pointer to ShellState */
 ){
-#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
+#ifndef SQLITE_ENABLE_STMT_SCANSTATUS
+  UNUSED_PARAMETER(db);
+  UNUSED_PARAMETER(pArg);
+#else
   int i, k, n, mx;
   fprintf(pArg->out, "-------- scanstats --------\n");
   mx = 0;
@@ -1910,6 +1913,7 @@ static void readfileFunc(
   long nIn;
   void *pBuf;
 
+  UNUSED_PARAMETER(argc);
   zName = (const char*)sqlite3_value_text(argv[0]);
   if( zName==0 ) return;
   in = fopen(zName, "rb");
@@ -1942,6 +1946,7 @@ static void writefileFunc(
   sqlite3_int64 rc;
   const char *zFile;
 
+  UNUSED_PARAMETER(argc);
   zFile = (const char*)sqlite3_value_text(argv[0]);
   if( zFile==0 ) return;
   out = fopen(zFile, "wb");
@@ -2666,7 +2671,7 @@ static int shell_dbinfo_command(ShellState *p, int nArg, char **azArg){
   fprintf(p->out, "%-20s %d\n", "write format:", aHdr[18]);
   fprintf(p->out, "%-20s %d\n", "read format:", aHdr[19]);
   fprintf(p->out, "%-20s %d\n", "reserved bytes:", aHdr[20]);
-  for(i=0; i<sizeof(aField)/sizeof(aField[0]); i++){
+  for(i=0; i<ArraySize(aField); i++){
     int ofst = aField[i].ofst;
     unsigned int val = get4byteInt(aHdr + ofst);
     fprintf(p->out, "%-20s %u", aField[i].zName, val);
@@ -2686,7 +2691,7 @@ static int shell_dbinfo_command(ShellState *p, int nArg, char **azArg){
   }else{
     zSchemaTab = sqlite3_mprintf("\"%w\".sqlite_master", zDb);
   }
-  for(i=0; i<sizeof(aQuery)/sizeof(aQuery[0]); i++){
+  for(i=0; i<ArraySize(aQuery); i++){
     char *zSql = sqlite3_mprintf(aQuery[i].zSql, zSchemaTab);
     int val = db_int(p, zSql);
     sqlite3_free(zSql);
@@ -3317,7 +3322,7 @@ static int do_meta_command(char *zLine, ShellState *p){
     int i, n2;
     open_db(p, 0);
     if( nArg==1 ){
-      for(i=0; i<sizeof(aLimit)/sizeof(aLimit[0]); i++){
+      for(i=0; i<ArraySize(aLimit); i++){
         printf("%20s %d\n", aLimit[i].zLimitName, 
                sqlite3_limit(p->db, aLimit[i].limitCode, -1));
       }
@@ -3328,7 +3333,7 @@ static int do_meta_command(char *zLine, ShellState *p){
     }else{
       int iLimit = -1;
       n2 = strlen30(azArg[1]);
-      for(i=0; i<sizeof(aLimit)/sizeof(aLimit[0]); i++){
+      for(i=0; i<ArraySize(aLimit); i++){
         if( sqlite3_strnicmp(aLimit[i].zLimitName, azArg[1], n2)==0 ){
           if( iLimit<0 ){
             iLimit = i;
@@ -3438,9 +3443,8 @@ static int do_meta_command(char *zLine, ShellState *p){
     const char *zSavedFilename = p->zDbFilename;
     char *zNewFilename = 0;
     p->db = 0;
-    if( nArg>=2 ){
-      p->zDbFilename = zNewFilename = sqlite3_mprintf("%s", azArg[1]);
-    }
+    if( nArg>=2 ) zNewFilename = sqlite3_mprintf("%s", azArg[1]);
+    p->zDbFilename = zNewFilename;
     open_db(p, 1);
     if( p->db!=0 ){
       session_close_all(p);
@@ -4096,7 +4100,7 @@ static int do_meta_command(char *zLine, ShellState *p){
     /* convert testctrl text option to value. allow any unique prefix
     ** of the option name, or a numerical value. */
     n2 = strlen30(azArg[1]);
-    for(i=0; i<(int)(sizeof(aCtrl)/sizeof(aCtrl[0])); i++){
+    for(i=0; i<ArraySize(aCtrl); i++){
       if( strncmp(azArg[1], aCtrl[i].zCtrlName, n2)==0 ){
         if( testctrl<0 ){
           testctrl = aCtrl[i].ctrlCode;
@@ -5073,7 +5077,7 @@ int SQLITE_CDECL main(int argc, char **argv){
           sqlite3_snprintf(nHistory, zHistory,"%s/.sqlite_history", zHome);
         }
       }
-      if( zHistory ) shell_read_history(zHistory);
+      if( zHistory ){ shell_read_history(zHistory); }
       rc = process_input(&data, 0);
       if( zHistory ){
         shell_stifle_history(100);
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index a04030df8..963b55c27 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -23,7 +23,7 @@
 **
 ** The official C-language API documentation for SQLite is derived
 ** from comments in this file.  This file is the authoritative source
-** on how SQLite interfaces are suppose to operate.
+** on how SQLite interfaces are supposed to operate.
 **
 ** The name of this file under configuration management is "sqlite.h.in".
 ** The makefile makes some minor changes to this file (such as inserting
diff --git a/src/sqlite3ext.h b/src/sqlite3ext.h
index 5c4488c3b..b56cc4e54 100644
--- a/src/sqlite3ext.h
+++ b/src/sqlite3ext.h
@@ -267,7 +267,8 @@ struct sqlite3_api_routines {
   void (*result_text64)(sqlite3_context*,const char*,sqlite3_uint64,
                          void(*)(void*), unsigned char);
   int (*strglob)(const char*,const char*);
-  sqlite3_value (*value_dup)(const sqlite3_value*);
+  /* Version 3.8.11 and later */
+  sqlite3_value *(*value_dup)(const sqlite3_value*);
   void (*value_free)(sqlite3_value*);
 };
 
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index a0608abbe..bcfc1ea3e 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3078,7 +3078,9 @@ int sqlite3CantopenError(int);
 # define sqlite3Isxdigit(x)  isxdigit((unsigned char)(x))
 # define sqlite3Tolower(x)   tolower((unsigned char)(x))
 #endif
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
 int sqlite3IsIdChar(u8);
+#endif
 
 /*
 ** Internal function prototypes
@@ -3106,7 +3108,9 @@ void sqlite3ScratchFree(void*);
 void *sqlite3PageMalloc(int);
 void sqlite3PageFree(void*);
 void sqlite3MemSetDefault(void);
+#ifndef SQLITE_OMIT_BUILTIN_TEST
 void sqlite3BenignMallocHooks(void (*)(void), void (*)(void));
+#endif
 int sqlite3HeapNearlyFull(void);
 
 /*
@@ -3250,7 +3254,9 @@ int sqlite3BitvecSet(Bitvec*, u32);
 void sqlite3BitvecClear(Bitvec*, u32, void*);
 void sqlite3BitvecDestroy(Bitvec*);
 u32 sqlite3BitvecSize(Bitvec*);
+#ifndef SQLITE_OMIT_BUILTIN_TEST
 int sqlite3BitvecBuiltinTest(int,int*);
+#endif
 
 RowSet *sqlite3RowSetInit(sqlite3*, void*, unsigned int);
 void sqlite3RowSetClear(RowSet*);
@@ -3355,8 +3361,10 @@ void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
 int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
 Vdbe *sqlite3GetVdbe(Parse*);
+#ifndef SQLITE_OMIT_BUILTIN_TEST
 void sqlite3PrngSaveState(void);
 void sqlite3PrngRestoreState(void);
+#endif
 void sqlite3RollbackAll(sqlite3*,int);
 void sqlite3CodeVerifySchema(Parse*, int);
 void sqlite3CodeVerifyNamedSchema(Parse*, const char *zDb);
diff --git a/src/tokenize.c b/src/tokenize.c
index b5934d247..3d08f75a2 100644
--- a/src/tokenize.c
+++ b/src/tokenize.c
@@ -102,7 +102,11 @@ const char sqlite3IsEbcdicIdChar[] = {
 };
 #define IdChar(C)  (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40]))
 #endif
+
+/* Make the IdChar function accessible from ctime.c */
+#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
 int sqlite3IsIdChar(u8 c){ return IdChar(c); }
+#endif
 
 
 /*
diff --git a/src/vdbe.c b/src/vdbe.c
index cba5c380e..ef639145c 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -3521,6 +3521,26 @@ case OP_Close: {
   break;
 }
 
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+/* Opcode: ColumnsUsed P1 * * P4 *
+**
+** This opcode (which only exists if SQLite was compiled with
+** SQLITE_ENABLE_COLUMN_USED_MASK) identifies which columns of the
+** table or index for cursor P1 are used.  P4 is a 64-bit integer
+** (P4_INT64) in which the first 63 bits are one for each of the
+** first 63 columns of the table or index that are actually used
+** by the cursor.  The high-order bit is set if any column after
+** the 64th is used.
+*/
+case OP_ColumnsUsed: {
+  VdbeCursor *pC;
+  pC = p->apCsr[pOp->p1];
+  assert( pC->pCursor );
+  pC->maskUsed = *(u64*)pOp->p4.pI64;
+  break;
+}
+#endif
+
 /* Opcode: SeekGE P1 P2 P3 P4 *
 ** Synopsis: key=r[P3@P4]
 **
diff --git a/src/vdbe.h b/src/vdbe.h
index ffce30377..f6a8b6107 100644
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -171,6 +171,7 @@ int sqlite3VdbeAddOp1(Vdbe*,int,int);
 int sqlite3VdbeAddOp2(Vdbe*,int,int,int);
 int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
+int sqlite3VdbeAddOp4Dup8(Vdbe*,int,int,int,int,const u8*,int);
 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp, int iLineno);
 void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 06ffd95b5..6fe6f6dc4 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -83,6 +83,9 @@ struct VdbeCursor {
   i64 seqCount;         /* Sequence counter */
   i64 movetoTarget;     /* Argument to the deferred sqlite3BtreeMoveto() */
   VdbeSorter *pSorter;  /* Sorter object for OP_SorterOpen cursors */
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+  u64 maskUsed;         /* Mask of columns used by this cursor */
+#endif
 
   /* Cached information about the header for the data record that the
   ** cursor is currently pointing to.  Only valid if cacheStatus matches
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 28018ed46..38ca6475c 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -235,6 +235,23 @@ int sqlite3VdbeAddOp4(
 }
 
 /*
+** Add an opcode that includes the p4 value with a P4_INT64 type.
+*/
+int sqlite3VdbeAddOp4Dup8(
+  Vdbe *p,            /* Add the opcode to this VM */
+  int op,             /* The new opcode */
+  int p1,             /* The P1 operand */
+  int p2,             /* The P2 operand */
+  int p3,             /* The P3 operand */
+  const u8 *zP4,      /* The P4 operand */
+  int p4type          /* P4 operand type */
+){
+  char *p4copy = sqlite3DbMallocRaw(sqlite3VdbeDb(p), 8);
+  if( p4copy ) memcpy(p4copy, zP4, 8);
+  return sqlite3VdbeAddOp4(p, op, p1, p2, p3, p4copy, p4type);
+}
+
+/*
 ** Add an OP_ParseSchema opcode.  This routine is broken out from
 ** sqlite3VdbeAddOp4() since it needs to also needs to mark all btrees
 ** as having been used.
@@ -398,6 +415,7 @@ static Op *opIterNext(VdbeOpIter *p){
 **   *  OP_VUpdate
 **   *  OP_VRename
 **   *  OP_FkCounter with P2==0 (immediate foreign key constraint)
+**   *  OP_CreateTable and OP_InitCoroutine (for CREATE TABLE AS SELECT ...)
 **
 ** Then check that the value of Parse.mayAbort is true if an
 ** ABORT may be thrown, or false otherwise. Return true if it does
@@ -409,6 +427,8 @@ static Op *opIterNext(VdbeOpIter *p){
 int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   int hasAbort = 0;
   int hasFkCounter = 0;
+  int hasCreateTable = 0;
+  int hasInitCoroutine = 0;
   Op *pOp;
   VdbeOpIter sIter;
   memset(&sIter, 0, sizeof(sIter));
@@ -423,6 +443,8 @@ int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
       hasAbort = 1;
       break;
     }
+    if( opcode==OP_CreateTable ) hasCreateTable = 1;
+    if( opcode==OP_InitCoroutine ) hasInitCoroutine = 1;
 #ifndef SQLITE_OMIT_FOREIGN_KEY
     if( opcode==OP_FkCounter && pOp->p1==0 && pOp->p2==1 ){
       hasFkCounter = 1;
@@ -436,7 +458,8 @@ int sqlite3VdbeAssertMayAbort(Vdbe *v, int mayAbort){
   ** through all opcodes and hasAbort may be set incorrectly. Return
   ** true for this case to prevent the assert() in the callers frame
   ** from failing.  */
-  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter );
+  return ( v->db->mallocFailed || hasAbort==mayAbort || hasFkCounter
+              || (hasCreateTable && hasInitCoroutine) );
 }
 #endif /* SQLITE_DEBUG - the sqlite3AssertMayAbort() function */
 
@@ -1219,12 +1242,11 @@ void sqlite3VdbeEnter(Vdbe *p){
 /*
 ** Unlock all of the btrees previously locked by a call to sqlite3VdbeEnter().
 */
-void sqlite3VdbeLeave(Vdbe *p){
+static SQLITE_NOINLINE void vdbeLeave(Vdbe *p){
   int i;
   sqlite3 *db;
   Db *aDb;
   int nDb;
-  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
   db = p->db;
   aDb = db->aDb;
   nDb = db->nDb;
@@ -1234,6 +1256,10 @@ void sqlite3VdbeLeave(Vdbe *p){
     }
   }
 }
+void sqlite3VdbeLeave(Vdbe *p){
+  if( DbMaskAllZero(p->lockMask) ) return;  /* The common case */
+  vdbeLeave(p);
+}
 #endif
 
 #if defined(VDBE_PROFILE) || defined(SQLITE_DEBUG)
diff --git a/src/vdbemem.c b/src/vdbemem.c
index 95378954f..c91ced11a 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -942,6 +942,32 @@ int sqlite3VdbeMemSetStr(
 ** If this routine fails for any reason (malloc returns NULL or unable
 ** to read from the disk) then the pMem is left in an inconsistent state.
 */
+static SQLITE_NOINLINE int vdbeMemFromBtreeResize(
+  BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
+  u32 offset,       /* Offset from the start of data to return bytes from. */
+  u32 amt,          /* Number of bytes to return. */
+  int key,          /* If true, retrieve from the btree key, not data. */
+  Mem *pMem         /* OUT: Return data in this Mem structure. */
+){
+  int rc;
+  pMem->flags = MEM_Null;
+  if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+2)) ){
+    if( key ){
+      rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
+    }else{
+      rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
+    }
+    if( rc==SQLITE_OK ){
+      pMem->z[amt] = 0;
+      pMem->z[amt+1] = 0;
+      pMem->flags = MEM_Blob|MEM_Term;
+      pMem->n = (int)amt;
+    }else{
+      sqlite3VdbeMemRelease(pMem);
+    }
+  }
+  return rc;
+}
 int sqlite3VdbeMemFromBtree(
   BtCursor *pCur,   /* Cursor pointing at record to retrieve. */
   u32 offset,       /* Offset from the start of data to return bytes from. */
@@ -971,22 +997,7 @@ int sqlite3VdbeMemFromBtree(
     pMem->flags = MEM_Blob|MEM_Ephem;
     pMem->n = (int)amt;
   }else{
-    pMem->flags = MEM_Null;
-    if( SQLITE_OK==(rc = sqlite3VdbeMemClearAndResize(pMem, amt+2)) ){
-      if( key ){
-        rc = sqlite3BtreeKey(pCur, offset, amt, pMem->z);
-      }else{
-        rc = sqlite3BtreeData(pCur, offset, amt, pMem->z);
-      }
-      if( rc==SQLITE_OK ){
-        pMem->z[amt] = 0;
-        pMem->z[amt+1] = 0;
-        pMem->flags = MEM_Blob|MEM_Term;
-        pMem->n = (int)amt;
-      }else{
-        sqlite3VdbeMemRelease(pMem);
-      }
-    }
+    rc = vdbeMemFromBtreeResize(pCur, offset, amt, key, pMem);
   }
 
   return rc;
diff --git a/src/where.c b/src/where.c
index e32d176ea..5be830e7e 100644
--- a/src/where.c
+++ b/src/where.c
@@ -4213,6 +4213,10 @@ WhereInfo *sqlite3WhereBegin(
                             SQLITE_INT_TO_PTR(n), P4_INT32);
         assert( n<=pTab->nCol );
       }
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+      sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, pTabItem->iCursor, 0, 0,
+                            (const u8*)&pTabItem->colUsed, P4_INT64);
+#endif
     }else{
       sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
     }
@@ -4258,6 +4262,21 @@ WhereInfo *sqlite3WhereBegin(
           sqlite3VdbeChangeP5(v, OPFLAG_SEEKEQ); /* Hint to COMDB2 */
         }
         VdbeComment((v, "%s", pIx->zName));
+#ifdef SQLITE_ENABLE_COLUMN_USED_MASK
+        {
+          u64 colUsed = 0;
+          int ii, jj;
+          for(ii=0; ii<pIx->nColumn; ii++){
+            jj = pIx->aiColumn[ii];
+            if( jj<0 ) continue;
+            if( jj>63 ) jj = 63;
+            if( (pTabItem->colUsed & MASKBIT(jj))==0 ) continue;
+            colUsed |= ((u64)1)<<(ii<63 ? ii : 63);
+          }
+          sqlite3VdbeAddOp4Dup8(v, OP_ColumnsUsed, iIndexCur, 0, 0,
+                                (u8*)&colUsed, P4_INT64);
+        }
+#endif /* SQLITE_ENABLE_COLUMN_USED_MASK */
       }
     }
     if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb);