Merge in all recent preformance enhancements from trunk.

FossilOrigin-Name: 32477642d79615fb85680bdac812ad9655cf6902

27 files changed, 451 insertions, 346 deletions

diff --git a/src/backup.c b/src/backup.c
index 1bac821f3..4a6bc7493 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -526,7 +526,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
 
           /* Sync the database file to disk. */
           if( rc==SQLITE_OK ){
-            rc = sqlite3PagerSync(pDestPager);
+            rc = sqlite3PagerSync(pDestPager, 0);
           }
         }else{
           sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
@@ -601,10 +601,10 @@ int sqlite3_backup_finish(sqlite3_backup *p){
 
   /* Set the error code of the destination database handle. */
   rc = (p->rc==SQLITE_DONE) ? SQLITE_OK : p->rc;
-  sqlite3Error(p->pDestDb, rc, 0);
-
-  /* Exit the mutexes and free the backup context structure. */
   if( p->pDestDb ){
+    sqlite3Error(p->pDestDb, rc, 0);
+
+    /* Exit the mutexes and free the backup context structure. */
     sqlite3LeaveMutexAndCloseZombie(p->pDestDb);
   }
   sqlite3BtreeLeave(p->pSrc);
diff --git a/src/btree.c b/src/btree.c
index 30fdf4256..20bed057e 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -1652,7 +1652,7 @@ static int getAndInitPage(
     rc = SQLITE_CORRUPT_BKPT;
   }else{
     rc = btreeGetPage(pBt, pgno, ppPage, bReadonly);
-    if( rc==SQLITE_OK ){
+    if( rc==SQLITE_OK && (*ppPage)->isInit==0 ){
       rc = btreeInitPage(*ppPage);
       if( rc!=SQLITE_OK ){
         releasePage(*ppPage);
@@ -1673,10 +1673,11 @@ static void releasePage(MemPage *pPage){
   if( pPage ){
     assert( pPage->aData );
     assert( pPage->pBt );
+    assert( pPage->pDbPage!=0 );
     assert( sqlite3PagerGetExtra(pPage->pDbPage) == (void*)pPage );
     assert( sqlite3PagerGetData(pPage->pDbPage)==pPage->aData );
     assert( sqlite3_mutex_held(pPage->pBt->mutex) );
-    sqlite3PagerUnref(pPage->pDbPage);
+    sqlite3PagerUnrefNotNull(pPage->pDbPage);
   }
 }
 
@@ -4192,10 +4193,10 @@ int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
 /*
 ** Return a pointer to payload information from the entry that the 
 ** pCur cursor is pointing to.  The pointer is to the beginning of
-** the key if skipKey==0 and it points to the beginning of data if
-** skipKey==1.  The number of bytes of available key/data is written
-** into *pAmt.  If *pAmt==0, then the value returned will not be
-** a valid pointer.
+** the key if index btrees (pPage->intKey==0) and is the data for
+** table btrees (pPage->intKey==1). The number of bytes of available
+** key/data is written into *pAmt.  If *pAmt==0, then the value
+** returned will not be a valid pointer.
 **
 ** This routine is an optimization.  It is common for the entire key
 ** and data to fit on the local page and for there to be no overflow
@@ -4208,41 +4209,21 @@ int sqlite3BtreeData(BtCursor *pCur, u32 offset, u32 amt, void *pBuf){
 ** page of the database.  The data might change or move the next time
 ** any btree routine is called.
 */
-static const unsigned char *fetchPayload(
+static const void *fetchPayload(
   BtCursor *pCur,      /* Cursor pointing to entry to read from */
-  u32 *pAmt,           /* Write the number of available bytes here */
-  int skipKey          /* read beginning at data if this is true */
+  u32 *pAmt            /* Write the number of available bytes here */
 ){
-  unsigned char *aPayload;
-  MemPage *pPage;
-  u32 nKey;
-  u32 nLocal;
-
   assert( pCur!=0 && pCur->iPage>=0 && pCur->apPage[pCur->iPage]);
   assert( pCur->eState==CURSOR_VALID );
+  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
   assert( cursorHoldsMutex(pCur) );
-  pPage = pCur->apPage[pCur->iPage];
-  assert( pCur->aiIdx[pCur->iPage]<pPage->nCell );
+  assert( pCur->aiIdx[pCur->iPage]<pCur->apPage[pCur->iPage]->nCell );
   if( pCur->info.nSize==0 ){
     btreeParseCell(pCur->apPage[pCur->iPage], pCur->aiIdx[pCur->iPage],
                    &pCur->info);
   }
-  aPayload = pCur->info.pCell;
-  aPayload += pCur->info.nHeader;
-  if( pPage->intKey ){
-    nKey = 0;
-  }else{
-    nKey = (int)pCur->info.nKey;
-  }
-  if( skipKey ){
-    aPayload += nKey;
-    nLocal = pCur->info.nLocal - nKey;
-  }else{
-    nLocal = pCur->info.nLocal;
-    assert( nLocal<=nKey );
-  }
-  *pAmt = nLocal;
-  return aPayload;
+  *pAmt = pCur->info.nLocal;
+  return (void*)(pCur->info.pCell + pCur->info.nHeader);
 }
 
 
@@ -4261,22 +4242,10 @@ static const unsigned char *fetchPayload(
 ** in the common case where no overflow pages are used.
 */
 const void *sqlite3BtreeKeyFetch(BtCursor *pCur, u32 *pAmt){
-  const void *p = 0;
-  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
-  assert( cursorHoldsMutex(pCur) );
-  if( ALWAYS(pCur->eState==CURSOR_VALID) ){
-    p = (const void*)fetchPayload(pCur, pAmt, 0);
-  }
-  return p;
+  return fetchPayload(pCur, pAmt);
 }
 const void *sqlite3BtreeDataFetch(BtCursor *pCur, u32 *pAmt){
-  const void *p = 0;
-  assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
-  assert( cursorHoldsMutex(pCur) );
-  if( ALWAYS(pCur->eState==CURSOR_VALID) ){
-    p = (const void*)fetchPayload(pCur, pAmt, 1);
-  }
-  return p;
+  return fetchPayload(pCur, pAmt);
 }
 
 
@@ -4395,8 +4364,6 @@ static void moveToParent(BtCursor *pCur){
 static int moveToRoot(BtCursor *pCur){
   MemPage *pRoot;
   int rc = SQLITE_OK;
-  Btree *p = pCur->pBtree;
-  BtShared *pBt = p->pBt;
 
   assert( cursorHoldsMutex(pCur) );
   assert( CURSOR_INVALID < CURSOR_REQUIRESEEK );
@@ -4411,16 +4378,12 @@ static int moveToRoot(BtCursor *pCur){
   }
 
   if( pCur->iPage>=0 ){
-    int i;
-    for(i=1; i<=pCur->iPage; i++){
-      releasePage(pCur->apPage[i]);
-    }
-    pCur->iPage = 0;
+    while( pCur->iPage ) releasePage(pCur->apPage[pCur->iPage--]);
   }else if( pCur->pgnoRoot==0 ){
     pCur->eState = CURSOR_INVALID;
     return SQLITE_OK;
   }else{
-    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0],
+    rc = getAndInitPage(pCur->pBtree->pBt, pCur->pgnoRoot, &pCur->apPage[0],
                         pCur->wrFlag==0 ? PAGER_GET_READONLY : 0);
     if( rc!=SQLITE_OK ){
       pCur->eState = CURSOR_INVALID;
@@ -4453,14 +4416,16 @@ static int moveToRoot(BtCursor *pCur){
   pCur->atLast = 0;
   pCur->validNKey = 0;
 
-  if( pRoot->nCell==0 && !pRoot->leaf ){
+  if( pRoot->nCell>0 ){
+    pCur->eState = CURSOR_VALID;
+  }else if( !pRoot->leaf ){
     Pgno subpage;
     if( pRoot->pgno!=1 ) return SQLITE_CORRUPT_BKPT;
     subpage = get4byte(&pRoot->aData[pRoot->hdrOffset+8]);
     pCur->eState = CURSOR_VALID;
     rc = moveToChild(pCur, subpage);
   }else{
-    pCur->eState = ((pRoot->nCell>0)?CURSOR_VALID:CURSOR_INVALID);
+    pCur->eState = CURSOR_INVALID;
   }
   return rc;
 }
@@ -4716,9 +4681,7 @@ int sqlite3BtreeMovetoUnpacked(
         ** 2 bytes of the cell.
         */
         nCell = pCell[0];
-        if( nCell<=pPage->max1bytePayload
-         /* && (pCell+nCell)<pPage->aDataEnd */
-        ){
+        if( nCell<=pPage->max1bytePayload ){
           /* This branch runs if the record-size field of the cell is a
           ** single byte varint and the record fits entirely on the main
           ** b-tree page.  */
@@ -4726,7 +4689,6 @@ int sqlite3BtreeMovetoUnpacked(
           c = sqlite3VdbeRecordCompare(nCell, (void*)&pCell[1], pIdxKey);
         }else if( !(pCell[1] & 0x80) 
           && (nCell = ((nCell&0x7f)<<7) + pCell[1])<=pPage->maxLocal
-          /* && (pCell+nCell+2)<=pPage->aDataEnd */
         ){
           /* The record-size field is a 2 byte varint and the record 
           ** fits entirely on the main b-tree page.  */
@@ -5550,7 +5512,7 @@ static int fillInCell(
     nHeader += 4;
   }
   if( pPage->hasData ){
-    nHeader += putVarint(&pCell[nHeader], nData+nZero);
+    nHeader += putVarint32(&pCell[nHeader], nData+nZero);
   }else{
     nData = nZero = 0;
   }
@@ -5678,7 +5640,6 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
   u32 pc;         /* Offset to cell content of cell being deleted */
   u8 *data;       /* pPage->aData */
   u8 *ptr;        /* Used to move bytes around within data[] */
-  u8 *endPtr;     /* End of loop */
   int rc;         /* The return code */
   int hdr;        /* Beginning of the header.  0 most pages.  100 page 1 */
 
@@ -5703,13 +5664,8 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
     *pRC = rc;
     return;
   }
-  endPtr = &pPage->aCellIdx[2*pPage->nCell - 2];
-  assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 );  /* ptr is always 2-byte aligned */
-  while( ptr<endPtr ){
-    *(u16*)ptr = *(u16*)&ptr[2];
-    ptr += 2;
-  }
   pPage->nCell--;
+  memmove(ptr, ptr+2, 2*(pPage->nCell - idx));
   put2byte(&data[hdr+3], pPage->nCell);
   pPage->nFree += 2;
 }
@@ -5746,9 +5702,6 @@ static void insertCell(
   int ins;          /* Index in data[] where new cell pointer is inserted */
   int cellOffset;   /* Address of first cell pointer in data[] */
   u8 *data;         /* The content of the whole page */
-  u8 *ptr;          /* Used for moving information around in data[] */
-  u8 *endPtr;       /* End of the loop */
-
   int nSkip = (iChild ? 4 : 0);
 
   if( *pRC ) return;
@@ -5799,13 +5752,7 @@ static void insertCell(
     if( iChild ){
       put4byte(&data[idx], iChild);
     }
-    ptr = &data[end];
-    endPtr = &data[ins];
-    assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 );  /* ptr is always 2-byte aligned */
-    while( ptr>endPtr ){
-      *(u16*)ptr = *(u16*)&ptr[-2];
-      ptr -= 2;
-    }
+    memmove(&data[ins+2], &data[ins], end-ins);
     put2byte(&data[ins], idx);
     put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
 #ifndef SQLITE_OMIT_AUTOVACUUM
@@ -7767,7 +7714,7 @@ static void checkAppendMsg(
     sqlite3StrAccumAppend(&pCheck->errMsg, "\n", 1);
   }
   if( zMsg1 ){
-    sqlite3StrAccumAppend(&pCheck->errMsg, zMsg1, -1);
+    sqlite3StrAccumAppendAll(&pCheck->errMsg, zMsg1);
   }
   sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
   va_end(ap);
diff --git a/src/build.c b/src/build.c
index fd512358b..c83ce57cf 100644
--- a/src/build.c
+++ b/src/build.c
@@ -3989,9 +3989,9 @@ void sqlite3UniqueConstraint(
   for(j=0; j<pIdx->nKeyCol; j++){
     char *zCol = pTab->aCol[pIdx->aiColumn[j]].zName;
     if( j ) sqlite3StrAccumAppend(&errMsg, ", ", 2);
-    sqlite3StrAccumAppend(&errMsg, pTab->zName, -1);
+    sqlite3StrAccumAppendAll(&errMsg, pTab->zName);
     sqlite3StrAccumAppend(&errMsg, ".", 1);
-    sqlite3StrAccumAppend(&errMsg, zCol, -1);
+    sqlite3StrAccumAppendAll(&errMsg, zCol);
   }
   zErr = sqlite3StrAccumFinish(&errMsg);
   sqlite3HaltConstraint(pParse, 
@@ -4183,8 +4183,9 @@ KeyInfo *sqlite3KeyInfoOfIndex(Parse *pParse, Index *pIdx){
       assert( sqlite3KeyInfoIsWriteable(pKey) );
       for(i=0; i<nCol; i++){
         char *zColl = pIdx->azColl[i];
-        if( NEVER(zColl==0) ) zColl = "BINARY";
-        pKey->aColl[i] = sqlite3LocateCollSeq(pParse, zColl);
+        assert( zColl!=0 );
+        pKey->aColl[i] = strcmp(zColl,"BINARY")==0 ? 0 :
+                          sqlite3LocateCollSeq(pParse, zColl);
         pKey->aSortOrder[i] = pIdx->aSortOrder[i];
       }
       if( pParse->nErr ){
diff --git a/src/callback.c b/src/callback.c
index 66fa49089..260fe806b 100644
--- a/src/callback.c
+++ b/src/callback.c
@@ -357,7 +357,6 @@ FuncDef *sqlite3FindFunction(
 
   assert( nArg>=(-2) );
   assert( nArg>=(-1) || createFlag==0 );
-  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
   h = (sqlite3UpperToLower[(u8)zName[0]] + nName) % ArraySize(db->aFunc.a);
 
   /* First search for a match amongst the application-defined functions.
diff --git a/src/func.c b/src/func.c
index 46c606ac0..951af97b3 100644
--- a/src/func.c
+++ b/src/func.c
@@ -1511,11 +1511,11 @@ static void groupConcatStep(
         zSep = ",";
         nSep = 1;
       }
-      sqlite3StrAccumAppend(pAccum, zSep, nSep);
+      if( nSep ) sqlite3StrAccumAppend(pAccum, zSep, nSep);
     }
     zVal = (char*)sqlite3_value_text(argv[0]);
     nVal = sqlite3_value_bytes(argv[0]);
-    sqlite3StrAccumAppend(pAccum, zVal, nVal);
+    if( nVal ) sqlite3StrAccumAppend(pAccum, zVal, nVal);
   }
 }
 static void groupConcatFinalize(sqlite3_context *context){
diff --git a/src/main.c b/src/main.c
index 7c8f1739f..c62aa3648 100644
--- a/src/main.c
+++ b/src/main.c
@@ -588,7 +588,8 @@ static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
     db->lookaside.bEnabled = 1;
     db->lookaside.bMalloced = pBuf==0 ?1:0;
   }else{
-    db->lookaside.pEnd = 0;
+    db->lookaside.pStart = db;
+    db->lookaside.pEnd = db;
     db->lookaside.bEnabled = 0;
     db->lookaside.bMalloced = 0;
   }
@@ -986,9 +987,7 @@ void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
 #endif
 
   sqlite3Error(db, SQLITE_OK, 0); /* Deallocates any cached error strings. */
-  if( db->pErr ){
-    sqlite3ValueFree(db->pErr);
-  }
+  sqlite3ValueFree(db->pErr);
   sqlite3CloseExtensions(db);
 
   db->magic = SQLITE_MAGIC_ERROR;
@@ -1086,6 +1085,7 @@ const char *sqlite3ErrName(int rc){
       case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
       case SQLITE_READONLY_CANTLOCK:  zName = "SQLITE_READONLY_CANTLOCK"; break;
       case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
+      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
       case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
       case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
       case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
@@ -1370,6 +1370,7 @@ int sqlite3CreateFunc(
 ){
   FuncDef *p;
   int nName;
+  int extraFlags;
 
   assert( sqlite3_mutex_held(db->mutex) );
   if( zFunctionName==0 ||
@@ -1380,6 +1381,10 @@ int sqlite3CreateFunc(
       (255<(nName = sqlite3Strlen30( zFunctionName))) ){
     return SQLITE_MISUSE_BKPT;
   }
+
+  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
+  extraFlags = enc &  SQLITE_DETERMINISTIC;
+  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
   
 #ifndef SQLITE_OMIT_UTF16
   /* If SQLITE_UTF16 is specified as the encoding type, transform this
@@ -1393,10 +1398,10 @@ int sqlite3CreateFunc(
     enc = SQLITE_UTF16NATIVE;
   }else if( enc==SQLITE_ANY ){
     int rc;
-    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8,
+    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
          pUserData, xFunc, xStep, xFinal, pDestructor);
     if( rc==SQLITE_OK ){
-      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE,
+      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
           pUserData, xFunc, xStep, xFinal, pDestructor);
     }
     if( rc!=SQLITE_OK ){
@@ -1439,7 +1444,8 @@ int sqlite3CreateFunc(
     pDestructor->nRef++;
   }
   p->pDestructor = pDestructor;
-  p->funcFlags &= SQLITE_FUNC_ENCMASK;
+  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
+  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
   p->xFunc = xFunc;
   p->xStep = xStep;
   p->xFinalize = xFinal;
@@ -1890,6 +1896,7 @@ const char *sqlite3_errmsg(sqlite3 *db){
   if( db->mallocFailed ){
     z = sqlite3ErrStr(SQLITE_NOMEM);
   }else{
+    testcase( db->pErr==0 );
     z = (char*)sqlite3_value_text(db->pErr);
     assert( !db->mallocFailed );
     if( z==0 ){
@@ -1931,8 +1938,7 @@ const void *sqlite3_errmsg16(sqlite3 *db){
   }else{
     z = sqlite3_value_text16(db->pErr);
     if( z==0 ){
-      sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
-           SQLITE_UTF8, SQLITE_STATIC);
+      sqlite3Error(db, db->errCode, sqlite3ErrStr(db->errCode));
       z = sqlite3_value_text16(db->pErr);
     }
     /* A malloc() may have failed within the call to sqlite3_value_text16()
@@ -2646,8 +2652,6 @@ static int openDatabase(
   }
 #endif
 
-  sqlite3Error(db, rc, 0);
-
   /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
   ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
   ** mode.  Doing nothing at all also makes NORMAL the default.
diff --git a/src/malloc.c b/src/malloc.c
index 799f0485d..9c11d0776 100644
--- a/src/malloc.c
+++ b/src/malloc.c
@@ -433,7 +433,7 @@ void sqlite3ScratchFree(void *p){
 */
 #ifndef SQLITE_OMIT_LOOKASIDE
 static int isLookaside(sqlite3 *db, void *p){
-  return p && p>=db->lookaside.pStart && p<db->lookaside.pEnd;
+  return p>=db->lookaside.pStart && p<db->lookaside.pEnd;
 }
 #else
 #define isLookaside(A,B) 0
@@ -449,8 +449,9 @@ int sqlite3MallocSize(void *p){
   return sqlite3GlobalConfig.m.xSize(p);
 }
 int sqlite3DbMallocSize(sqlite3 *db, void *p){
-  assert( db==0 || sqlite3_mutex_held(db->mutex) );
-  if( db && isLookaside(db, p) ){
+  assert( db!=0 );
+  assert( sqlite3_mutex_held(db->mutex) );
+  if( isLookaside(db, p) ){
     return db->lookaside.sz;
   }else{
     assert( sqlite3MemdebugHasType(p, MEMTYPE_DB) );
diff --git a/src/os_unix.c b/src/os_unix.c
index ab657dc7b..485b32fd9 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -1315,6 +1315,15 @@ static int findInodeInfo(
   return SQLITE_OK;
 }
 
+/*
+** Return TRUE if pFile has been renamed or unlinked since it was first opened.
+*/
+static int fileHasMoved(unixFile *pFile){
+  struct stat buf;
+  return pFile->pInode!=0 &&
+         (osStat(pFile->zPath, &buf)!=0 || buf.st_ino!=pFile->pInode->fileId.ino);
+}
+
 
 /*
 ** Check a unixFile that is a database.  Verify the following:
@@ -1349,10 +1358,7 @@ static void verifyDbFile(unixFile *pFile){
     pFile->ctrlFlags |= UNIXFILE_WARNED;
     return;
   }
-  if( pFile->pInode!=0
-   && ((rc = osStat(pFile->zPath, &buf))!=0
-       || buf.st_ino!=pFile->pInode->fileId.ino)
-  ){
+  if( fileHasMoved(pFile) ){
     sqlite3_log(SQLITE_WARNING, "file renamed while open: %s", pFile->zPath);
     pFile->ctrlFlags |= UNIXFILE_WARNED;
     return;
@@ -3801,6 +3807,10 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
       }
       return SQLITE_OK;
     }
+    case SQLITE_FCNTL_HAS_MOVED: {
+      *(int*)pArg = fileHasMoved(pFile);
+      return SQLITE_OK;
+    }
 #if SQLITE_MAX_MMAP_SIZE>0
     case SQLITE_FCNTL_MMAP_SIZE: {
       i64 newLimit = *(i64*)pArg;
diff --git a/src/os_win.c b/src/os_win.c
index 22052a3fe..faa60569c 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -3119,7 +3119,7 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
       return SQLITE_OK;
     }
     case SQLITE_FCNTL_VFSNAME: {
-      *(char**)pArg = sqlite3_mprintf("win32");
+      *(char**)pArg = sqlite3_mprintf("%s", pFile->pVfs->zName);
       OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
       return SQLITE_OK;
     }
diff --git a/src/pager.c b/src/pager.c
index d675b8582..954ba7f1e 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -1024,15 +1024,12 @@ static char *print_pager_state(Pager *p){
 static int subjRequiresPage(PgHdr *pPg){
   Pager *pPager = pPg->pPager;
   PagerSavepoint *p;
-  Pgno pgno;
+  Pgno pgno = pPg->pgno;
   int i;
-  if( pPager->nSavepoint ){
-    pgno = pPg->pgno;
-    for(i=0; i<pPager->nSavepoint; i++){
-      p = &pPager->aSavepoint[i];
-      if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
-        return 1;
-      }
+  for(i=0; i<pPager->nSavepoint; i++){
+    p = &pPager->aSavepoint[i];
+    if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
+      return 1;
     }
   }
   return 0;
@@ -1041,8 +1038,8 @@ static int subjRequiresPage(PgHdr *pPg){
 /*
 ** Return true if the page is already in the journal file.
 */
-static int pageInJournal(PgHdr *pPg){
-  return sqlite3BitvecTest(pPg->pPager->pInJournal, pPg->pgno);
+static int pageInJournal(Pager *pPager, PgHdr *pPg){
+  return sqlite3BitvecTest(pPager->pInJournal, pPg->pgno);
 }
 
 /*
@@ -1249,6 +1246,7 @@ static int readMasterJournal(sqlite3_file *pJrnl, char *zMaster, u32 nMaster){
    || szJ<16
    || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-16, &len))
    || len>=nMaster 
+   || len==0 
    || SQLITE_OK!=(rc = read32bits(pJrnl, szJ-12, &cksum))
    || SQLITE_OK!=(rc = sqlite3OsRead(pJrnl, aMagic, 8, szJ-8))
    || memcmp(aMagic, aJournalMagic, 8)
@@ -1989,7 +1987,7 @@ static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
     PgHdr *p = pager_lookup(pPager, 1);
     if( p ){
       p->pageHash = 0;
-      sqlite3PagerUnref(p);
+      sqlite3PagerUnrefNotNull(p);
     }
   }
 #endif
@@ -2018,6 +2016,11 @@ static int pager_end_transaction(Pager *pPager, int hasMaster, int bCommit){
     rc = pager_truncate(pPager, pPager->dbSize);
   }
 
+  if( rc==SQLITE_OK && bCommit && isOpen(pPager->fd) ){
+    rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_COMMIT_PHASETWO, 0);
+    if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+  }
+
   if( !pPager->exclusiveMode 
    && (!pagerUseWal(pPager) || sqlite3WalExclusiveMode(pPager->pWal, 0))
   ){
@@ -2831,7 +2834,7 @@ end_playback:
   if( rc==SQLITE_OK
    && (pPager->eState>=PAGER_WRITER_DBMOD || pPager->eState==PAGER_OPEN)
   ){
-    rc = sqlite3PagerSync(pPager);
+    rc = sqlite3PagerSync(pPager, 0);
   }
   if( rc==SQLITE_OK ){
     rc = pager_end_transaction(pPager, zMaster[0]!='\0', 0);
@@ -2977,7 +2980,7 @@ static int pagerUndoCallback(void *pCtx, Pgno iPg){
       if( rc==SQLITE_OK ){
         pPager->xReiniter(pPg);
       }
-      sqlite3PagerUnref(pPg);
+      sqlite3PagerUnrefNotNull(pPg);
     }
   }
 
@@ -4332,7 +4335,7 @@ static int subjournalPage(PgHdr *pPg){
     assert( isOpen(pPager->jfd) || pagerUseWal(pPager) );
     assert( isOpen(pPager->sjfd) || pPager->nSubRec==0 );
     assert( pagerUseWal(pPager) 
-         || pageInJournal(pPg) 
+         || pageInJournal(pPager, pPg) 
          || pPg->pgno>pPager->dbOrigSize 
     );
     rc = openSubJournal(pPager);
@@ -4797,6 +4800,30 @@ int sqlite3PagerOpen(
 }
 
 
+/* Verify that the database file has not be deleted or renamed out from
+** under the pager.  Return SQLITE_OK if the database is still were it ought
+** to be on disk.  Return non-zero (SQLITE_READONLY_DBMOVED or some other error
+** code from sqlite3OsAccess()) if the database has gone missing.
+*/
+static int databaseIsUnmoved(Pager *pPager){
+  int bHasMoved = 0;
+  int rc;
+
+  if( pPager->tempFile ) return SQLITE_OK;
+  if( pPager->dbSize==0 ) return SQLITE_OK;
+  assert( pPager->zFilename && pPager->zFilename[0] );
+  rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_HAS_MOVED, &bHasMoved);
+  if( rc==SQLITE_NOTFOUND ){
+    /* If the HAS_MOVED file-control is unimplemented, assume that the file
+    ** has not been moved.  That is the historical behavior of SQLite: prior to
+    ** version 3.8.3, it never checked */
+    rc = SQLITE_OK;
+  }else if( rc==SQLITE_OK && bHasMoved ){
+    rc = SQLITE_READONLY_DBMOVED;
+  }
+  return rc;
+}
+
 
 /*
 ** This function is called after transitioning from PAGER_UNLOCK to
@@ -5268,7 +5295,7 @@ int sqlite3PagerAcquire(
       if( rc!=SQLITE_OK ) goto pager_acquire_err;
     }
 
-    if( iFrame==0 && bMmapOk ){
+    if( bMmapOk && iFrame==0 ){
       void *pData = 0;
 
       rc = sqlite3OsFetch(pPager->fd, 
@@ -5409,16 +5436,19 @@ DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno){
 ** are released, a rollback occurs and the lock on the database is
 ** removed.
 */
-void sqlite3PagerUnref(DbPage *pPg){
-  if( pPg ){
-    Pager *pPager = pPg->pPager;
-    if( pPg->flags & PGHDR_MMAP ){
-      pagerReleaseMapPage(pPg);
-    }else{
-      sqlite3PcacheRelease(pPg);
-    }
-    pagerUnlockIfUnused(pPager);
+void sqlite3PagerUnrefNotNull(DbPage *pPg){
+  Pager *pPager;
+  assert( pPg!=0 );
+  pPager = pPg->pPager;
+  if( pPg->flags & PGHDR_MMAP ){
+    pagerReleaseMapPage(pPg);
+  }else{
+    sqlite3PcacheRelease(pPg);
   }
+  pagerUnlockIfUnused(pPager);
+}
+void sqlite3PagerUnref(DbPage *pPg){
+  if( pPg ) sqlite3PagerUnrefNotNull(pPg);
 }
 
 /*
@@ -5473,13 +5503,19 @@ static int pager_open_journal(Pager *pPager){
             (SQLITE_OPEN_DELETEONCLOSE|SQLITE_OPEN_TEMP_JOURNAL):
             (SQLITE_OPEN_MAIN_JOURNAL)
           );
-  #ifdef SQLITE_ENABLE_ATOMIC_WRITE
-        rc = sqlite3JournalOpen(
-            pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
-        );
-  #else
-        rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
-  #endif
+
+        /* Verify that the database still has the same name as it did when
+        ** it was originally opened. */
+        rc = databaseIsUnmoved(pPager);
+        if( rc==SQLITE_OK ){
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+          rc = sqlite3JournalOpen(
+              pVfs, pPager->zJournal, pPager->jfd, flags, jrnlBufferSize(pPager)
+          );
+#else
+          rc = sqlite3OsOpen(pVfs, pPager->zJournal, pPager->jfd, flags, 0);
+#endif
+        }
       }
       assert( rc!=SQLITE_OK || isOpen(pPager->jfd) );
     }
@@ -5600,9 +5636,9 @@ int sqlite3PagerBegin(Pager *pPager, int exFlag, int subjInMemory){
 ** of any open savepoints as appropriate.
 */
 static int pager_write(PgHdr *pPg){
-  void *pData = pPg->pData;
   Pager *pPager = pPg->pPager;
   int rc = SQLITE_OK;
+  int inJournal;
 
   /* This routine is not called unless a write-transaction has already 
   ** been started. The journal file may or may not be open at this point.
@@ -5613,14 +5649,8 @@ static int pager_write(PgHdr *pPg){
        || pPager->eState==PAGER_WRITER_DBMOD
   );
   assert( assert_pager_state(pPager) );
-
-  /* If an error has been previously detected, report the same error
-  ** again. This should not happen, but the check provides robustness. */
-  if( NEVER(pPager->errCode) )  return pPager->errCode;
-
-  /* Higher-level routines never call this function if database is not
-  ** writable.  But check anyway, just for robustness. */
-  if( NEVER(pPager->readOnly) ) return SQLITE_PERM;
+  assert( pPager->errCode==0 );
+  assert( pPager->readOnly==0 );
 
   CHECK_PAGE(pPg);
 
@@ -5644,7 +5674,8 @@ static int pager_write(PgHdr *pPg){
   ** to the journal then we can return right away.
   */
   sqlite3PcacheMakeDirty(pPg);
-  if( pageInJournal(pPg) && !subjRequiresPage(pPg) ){
+  inJournal = pageInJournal(pPager, pPg);
+  if( inJournal && (pPager->nSavepoint==0 || !subjRequiresPage(pPg)) ){
     assert( !pagerUseWal(pPager) );
   }else{
   
@@ -5652,7 +5683,7 @@ static int pager_write(PgHdr *pPg){
     ** EXCLUSIVE lock on the main database file.  Write the current page to
     ** the transaction journal if it is not there already.
     */
-    if( !pageInJournal(pPg) && !pagerUseWal(pPager) ){
+    if( !inJournal && !pagerUseWal(pPager) ){
       assert( pagerUseWal(pPager)==0 );
       if( pPg->pgno<=pPager->dbOrigSize && isOpen(pPager->jfd) ){
         u32 cksum;
@@ -5665,7 +5696,7 @@ static int pager_write(PgHdr *pPg){
         assert( pPg->pgno!=PAGER_MJ_PGNO(pPager) );
 
         assert( pPager->journalHdr<=pPager->journalOff );
-        CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
+        CODEC2(pPager, pPg->pData, pPg->pgno, 7, return SQLITE_NOMEM, pData2);
         cksum = pager_cksum(pPager, (u8*)pData2);
 
         /* Even if an IO or diskfull error occurs while journalling the
@@ -5717,7 +5748,7 @@ static int pager_write(PgHdr *pPg){
     ** the statement journal format differs from the standard journal format
     ** in that it omits the checksums and the header.
     */
-    if( subjRequiresPage(pPg) ){
+    if( pPager->nSavepoint>0 && subjRequiresPage(pPg) ){
       rc = subjournalPage(pPg);
     }
   }
@@ -5749,19 +5780,19 @@ int sqlite3PagerWrite(DbPage *pDbPage){
 
   PgHdr *pPg = pDbPage;
   Pager *pPager = pPg->pPager;
-  Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
 
   assert( (pPg->flags & PGHDR_MMAP)==0 );
   assert( pPager->eState>=PAGER_WRITER_LOCKED );
   assert( pPager->eState!=PAGER_ERROR );
   assert( assert_pager_state(pPager) );
 
-  if( nPagePerSector>1 ){
+  if( pPager->sectorSize > (u32)pPager->pageSize ){
     Pgno nPageCount;          /* Total number of pages in database file */
     Pgno pg1;                 /* First page of the sector pPg is located on. */
     int nPage = 0;            /* Number of pages starting at pg1 to journal */
     int ii;                   /* Loop counter */
     int needSync = 0;         /* True if any page has PGHDR_NEED_SYNC */
+    Pgno nPagePerSector = (pPager->sectorSize/pPager->pageSize);
 
     /* Set the doNotSpill NOSYNC bit to 1. This is because we cannot allow
     ** a journal header to be written between the pages journaled by
@@ -5800,14 +5831,14 @@ int sqlite3PagerWrite(DbPage *pDbPage){
             if( pPage->flags&PGHDR_NEED_SYNC ){
               needSync = 1;
             }
-            sqlite3PagerUnref(pPage);
+            sqlite3PagerUnrefNotNull(pPage);
           }
         }
       }else if( (pPage = pager_lookup(pPager, pg))!=0 ){
         if( pPage->flags&PGHDR_NEED_SYNC ){
           needSync = 1;
         }
-        sqlite3PagerUnref(pPage);
+        sqlite3PagerUnrefNotNull(pPage);
       }
     }
 
@@ -5823,7 +5854,7 @@ int sqlite3PagerWrite(DbPage *pDbPage){
         PgHdr *pPage = pager_lookup(pPager, pg1+ii);
         if( pPage ){
           pPage->flags |= PGHDR_NEED_SYNC;
-          sqlite3PagerUnref(pPage);
+          sqlite3PagerUnrefNotNull(pPage);
         }
       }
     }
@@ -5976,17 +6007,17 @@ static int pager_incr_changecounter(Pager *pPager, int isDirectMode){
 ** If successful, or if called on a pager for which it is a no-op, this
 ** function returns SQLITE_OK. Otherwise, an IO error code is returned.
 */
-int sqlite3PagerSync(Pager *pPager){
+int sqlite3PagerSync(Pager *pPager, const char *zMaster){
   int rc = SQLITE_OK;
-  if( !pPager->noSync ){
+
+  if( isOpen(pPager->fd) ){
+    void *pArg = (void*)zMaster;
+    rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC, pArg);
+    if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
+  }
+  if( rc==SQLITE_OK && !pPager->noSync ){
     assert( !MEMDB );
     rc = sqlite3OsSync(pPager->fd, pPager->syncFlags);
-  }else if( isOpen(pPager->fd) ){
-    assert( !MEMDB );
-    rc = sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SYNC_OMITTED, 0);
-    if( rc==SQLITE_NOTFOUND ){
-      rc = SQLITE_OK;
-    }
   }
   return rc;
 }
@@ -6185,7 +6216,7 @@ int sqlite3PagerCommitPhaseOne(
   
       /* Finally, sync the database file. */
       if( !noSync ){
-        rc = sqlite3PagerSync(pPager);
+        rc = sqlite3PagerSync(pPager, zMaster);
       }
       IOTRACE(("DBSYNC %p\n", pPager))
     }
@@ -6314,7 +6345,9 @@ int sqlite3PagerRollback(Pager *pPager){
 
   assert( pPager->eState==PAGER_READER || rc!=SQLITE_OK );
   assert( rc==SQLITE_OK || rc==SQLITE_FULL || rc==SQLITE_CORRUPT
-          || rc==SQLITE_NOMEM || (rc&0xFF)==SQLITE_IOERR );
+          || rc==SQLITE_NOMEM || (rc&0xFF)==SQLITE_IOERR 
+          || rc==SQLITE_CANTOPEN
+  );
 
   /* If an error occurs during a ROLLBACK, we can no longer trust the pager
   ** cache. So call pager_error() on the way out to make any error persistent.
@@ -6717,7 +6750,7 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
   if( (pPg->flags&PGHDR_NEED_SYNC) && !isCommit ){
     needSyncPgno = pPg->pgno;
     assert( pPager->journalMode==PAGER_JOURNALMODE_OFF ||
-            pageInJournal(pPg) || pPg->pgno>pPager->dbOrigSize );
+            pageInJournal(pPager, pPg) || pPg->pgno>pPager->dbOrigSize );
     assert( pPg->flags&PGHDR_DIRTY );
   }
 
@@ -6751,7 +6784,7 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
   if( MEMDB ){
     assert( pPgOld );
     sqlite3PcacheMove(pPgOld, origPgno);
-    sqlite3PagerUnref(pPgOld);
+    sqlite3PagerUnrefNotNull(pPgOld);
   }
 
   if( needSyncPgno ){
@@ -6780,7 +6813,7 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno, int isCommit){
     }
     pPgHdr->flags |= PGHDR_NEED_SYNC;
     sqlite3PcacheMakeDirty(pPgHdr);
-    sqlite3PagerUnref(pPgHdr);
+    sqlite3PagerUnrefNotNull(pPgHdr);
   }
 
   return SQLITE_OK;
diff --git a/src/pager.h b/src/pager.h
index 7851d2834..c9ca8553b 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -136,6 +136,7 @@ int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
 DbPage *sqlite3PagerLookup(Pager *pPager, Pgno pgno);
 void sqlite3PagerRef(DbPage*);
 void sqlite3PagerUnref(DbPage*);
+void sqlite3PagerUnrefNotNull(DbPage*);
 
 /* Operations on page references. */
 int sqlite3PagerWrite(DbPage*);
@@ -150,7 +151,7 @@ void sqlite3PagerPagecount(Pager*, int*);
 int sqlite3PagerBegin(Pager*, int exFlag, int);
 int sqlite3PagerCommitPhaseOne(Pager*,const char *zMaster, int);
 int sqlite3PagerExclusiveLock(Pager*);
-int sqlite3PagerSync(Pager *pPager);
+int sqlite3PagerSync(Pager *pPager, const char *zMaster);
 int sqlite3PagerCommitPhaseTwo(Pager*);
 int sqlite3PagerRollback(Pager*);
 int sqlite3PagerOpenSavepoint(Pager *pPager, int n);
diff --git a/src/pcache1.c b/src/pcache1.c
index df9d87753..f173e23fe 100644
--- a/src/pcache1.c
+++ b/src/pcache1.c
@@ -96,6 +96,7 @@ struct PCache1 {
 struct PgHdr1 {
   sqlite3_pcache_page page;
   unsigned int iKey;             /* Key value (page number) */
+  u8 isPinned;                   /* Page in use, not on the LRU list */
   PgHdr1 *pNext;                 /* Next in hash table chain */
   PCache1 *pCache;               /* Cache that currently owns this page */
   PgHdr1 *pLruNext;              /* Next in LRU list of unpinned pages */
@@ -424,34 +425,32 @@ static int pcache1ResizeHash(PCache1 *p){
 ** LRU list, then this function is a no-op.
 **
 ** The PGroup mutex must be held when this function is called.
-**
-** If pPage is NULL then this routine is a no-op.
 */
 static void pcache1PinPage(PgHdr1 *pPage){
   PCache1 *pCache;
   PGroup *pGroup;
 
-  if( pPage==0 ) return;
+  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) );
-  if( pPage->pLruNext || pPage==pGroup->pLruTail ){
-    if( pPage->pLruPrev ){
-      pPage->pLruPrev->pLruNext = pPage->pLruNext;
-    }
-    if( pPage->pLruNext ){
-      pPage->pLruNext->pLruPrev = pPage->pLruPrev;
-    }
-    if( pGroup->pLruHead==pPage ){
-      pGroup->pLruHead = pPage->pLruNext;
-    }
-    if( pGroup->pLruTail==pPage ){
-      pGroup->pLruTail = pPage->pLruPrev;
-    }
-    pPage->pLruNext = 0;
-    pPage->pLruPrev = 0;
-    pPage->pCache->nRecyclable--;
+  if( pPage->pLruPrev ){
+    pPage->pLruPrev->pLruNext = pPage->pLruNext;
+  }else{
+    pGroup->pLruHead = pPage->pLruNext;
+  }
+  if( pPage->pLruNext ){
+    pPage->pLruNext->pLruPrev = pPage->pLruPrev;
+  }else{
+    pGroup->pLruTail = pPage->pLruPrev;
   }
+  pPage->pLruNext = 0;
+  pPage->pLruPrev = 0;
+  pPage->isPinned = 1;
+  pCache->nRecyclable--;
 }
 
 
@@ -483,6 +482,7 @@ static void pcache1EnforceMaxPage(PGroup *pGroup){
   while( pGroup->nCurrentPage>pGroup->nMaxPage && pGroup->pLruTail ){
     PgHdr1 *p = pGroup->pLruTail;
     assert( p->pCache->pGroup==pGroup );
+    assert( p->isPinned==0 );
     pcache1PinPage(p);
     pcache1RemoveFromHash(p);
     pcache1FreePage(p);
@@ -510,7 +510,7 @@ static void pcache1TruncateUnsafe(
       if( pPage->iKey>=iLimit ){
         pCache->nPage--;
         *pp = pPage->pNext;
-        pcache1PinPage(pPage);
+        if( !pPage->isPinned ) pcache1PinPage(pPage);
         pcache1FreePage(pPage);
       }else{
         pp = &pPage->pNext;
@@ -733,8 +733,11 @@ static sqlite3_pcache_page *pcache1Fetch(
   }
 
   /* Step 2: Abort if no existing page is found and createFlag is 0 */
-  if( pPage || createFlag==0 ){
-    pcache1PinPage(pPage);
+  if( pPage ){
+    if( !pPage->isPinned ) pcache1PinPage(pPage);
+    goto fetch_out;
+  }
+  if( createFlag==0 ){
     goto fetch_out;
   }
 
@@ -775,6 +778,7 @@ static sqlite3_pcache_page *pcache1Fetch(
   )){
     PCache1 *pOther;
     pPage = pGroup->pLruTail;
+    assert( pPage->isPinned==0 );
     pcache1RemoveFromHash(pPage);
     pcache1PinPage(pPage);
     pOther = pPage->pCache;
@@ -811,6 +815,7 @@ static sqlite3_pcache_page *pcache1Fetch(
     pPage->pCache = pCache;
     pPage->pLruPrev = 0;
     pPage->pLruNext = 0;
+    pPage->isPinned = 1;
     *(void **)pPage->page.pExtra = 0;
     pCache->apHash[h] = pPage;
   }
@@ -846,6 +851,7 @@ static void pcache1Unpin(
   */
   assert( pPage->pLruPrev==0 && pPage->pLruNext==0 );
   assert( pGroup->pLruHead!=pPage && pGroup->pLruTail!=pPage );
+  assert( pPage->isPinned==1 );
 
   if( reuseUnlikely || pGroup->nCurrentPage>pGroup->nMaxPage ){
     pcache1RemoveFromHash(pPage);
@@ -861,6 +867,7 @@ static void pcache1Unpin(
       pGroup->pLruHead = pPage;
     }
     pCache->nRecyclable++;
+    pPage->isPinned = 0;
   }
 
   pcache1LeaveMutex(pCache->pGroup);
@@ -987,6 +994,7 @@ int sqlite3PcacheReleaseMemory(int nReq){
 #ifdef SQLITE_PCACHE_SEPARATE_HEADER
       nFree += sqlite3MemSize(p);
 #endif
+      assert( p->isPinned==0 );
       pcache1PinPage(p);
       pcache1RemoveFromHash(p);
       pcache1FreePage(p);
@@ -1011,6 +1019,7 @@ void sqlite3PcacheStats(
   PgHdr1 *p;
   int nRecyclable = 0;
   for(p=pcache1.grp.pLruHead; p; p=p->pLruNext){
+    assert( p->isPinned==0 );
     nRecyclable++;
   }
   *pnCurrent = pcache1.grp.nCurrentPage;
diff --git a/src/printf.c b/src/printf.c
index f9e5c6406..3279a54f2 100644
--- a/src/printf.c
+++ b/src/printf.c
@@ -149,6 +149,14 @@ void sqlite3AppendSpace(StrAccum *pAccum, int N){
 }
 
 /*
+** Set the StrAccum object to an error mode.
+*/
+void setStrAccumError(StrAccum *p, u8 eError){
+  p->accError = eError;
+  p->nAlloc = 0;
+}
+
+/*
 ** On machines with a small stack size, you can redefine the
 ** SQLITE_PRINT_BUF_SIZE to be something smaller, if desired.
 */
@@ -359,7 +367,7 @@ void sqlite3VXPrintf(
           nOut = precision + 10;
           zOut = zExtra = sqlite3Malloc( nOut );
           if( zOut==0 ){
-            pAccum->accError = STRACCUM_NOMEM;
+            setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
           }
         }
@@ -471,7 +479,7 @@ void sqlite3VXPrintf(
         if( MAX(e2,0)+precision+width > etBUFSIZE - 15 ){
           bufpt = zExtra = sqlite3Malloc( MAX(e2,0)+precision+width+15 );
           if( bufpt==0 ){
-            pAccum->accError = STRACCUM_NOMEM;
+            setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
           }
         }
@@ -606,7 +614,7 @@ void sqlite3VXPrintf(
         if( n>etBUFSIZE ){
           bufpt = zExtra = sqlite3Malloc( n );
           if( bufpt==0 ){
-            pAccum->accError = STRACCUM_NOMEM;
+            setStrAccumError(pAccum, STRACCUM_NOMEM);
             return;
           }
         }else{
@@ -629,7 +637,7 @@ void sqlite3VXPrintf(
       }
       case etTOKEN: {
         Token *pToken = va_arg(ap, Token*);
-        if( pToken ){
+        if( pToken && pToken->n ){
           sqlite3StrAccumAppend(pAccum, (const char*)pToken->z, pToken->n);
         }
         length = width = 0;
@@ -641,10 +649,10 @@ void sqlite3VXPrintf(
         struct SrcList_item *pItem = &pSrc->a[k];
         assert( k>=0 && k<pSrc->nSrc );
         if( pItem->zDatabase ){
-          sqlite3StrAccumAppend(pAccum, pItem->zDatabase, -1);
+          sqlite3StrAccumAppendAll(pAccum, pItem->zDatabase);
           sqlite3StrAccumAppend(pAccum, ".", 1);
         }
-        sqlite3StrAccumAppend(pAccum, pItem->zName, -1);
+        sqlite3StrAccumAppendAll(pAccum, pItem->zName);
         length = width = 0;
         break;
       }
@@ -675,7 +683,7 @@ void sqlite3VXPrintf(
         sqlite3AppendSpace(pAccum, nspace);
       }
     }
-    sqlite3_free(zExtra);
+    if( zExtra ) sqlite3_free(zExtra);
   }/* End for loop over the format string */
 } /* End of function */
 
@@ -683,22 +691,20 @@ void sqlite3VXPrintf(
 ** Append N bytes of text from z to the StrAccum object.
 */
 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
-  assert( z!=0 || N==0 );
-  if( p->accError ){
-    testcase(p->accError==STRACCUM_TOOBIG);
-    testcase(p->accError==STRACCUM_NOMEM);
-    return;
-  }
-  assert( p->zText!=0 || p->nChar==0 );
-  if( N<=0 ){
-    if( N==0 || z[0]==0 ) return;
-    N = sqlite3Strlen30(z);
-  }
+  assert( z!=0 );
+  assert( p->zText!=0 || p->nChar==0 || p->accError );
+  assert( N>=0 );
+  assert( p->accError==0 || p->nAlloc==0 );
   if( p->nChar+N >= p->nAlloc ){
     char *zNew;
+    if( p->accError ){
+      testcase(p->accError==STRACCUM_TOOBIG);
+      testcase(p->accError==STRACCUM_NOMEM);
+      return;
+    }
     if( !p->useMalloc ){
-      p->accError = STRACCUM_TOOBIG;
       N = p->nAlloc - p->nChar - 1;
+      setStrAccumError(p, STRACCUM_TOOBIG);
       if( N<=0 ){
         return;
       }
@@ -708,7 +714,7 @@ void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
       szNew += N + 1;
       if( szNew > p->mxAlloc ){
         sqlite3StrAccumReset(p);
-        p->accError = STRACCUM_TOOBIG;
+        setStrAccumError(p, STRACCUM_TOOBIG);
         return;
       }else{
         p->nAlloc = (int)szNew;
@@ -722,8 +728,8 @@ void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
         if( zOld==0 && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
         p->zText = zNew;
       }else{
-        p->accError = STRACCUM_NOMEM;
         sqlite3StrAccumReset(p);
+        setStrAccumError(p, STRACCUM_NOMEM);
         return;
       }
     }
@@ -734,6 +740,14 @@ void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
 }
 
 /*
+** Append the complete text of zero-terminated string z[] to the p string.
+*/
+void sqlite3StrAccumAppendAll(StrAccum *p, const char *z){
+  sqlite3StrAccumAppend(p, z, sqlite3Strlen30(z));
+}
+
+
+/*
 ** Finish off a string by making sure it is zero-terminated.
 ** Return a pointer to the resulting string.  Return a NULL
 ** pointer if any kind of error was encountered.
@@ -750,7 +764,7 @@ char *sqlite3StrAccumFinish(StrAccum *p){
       if( p->zText ){
         memcpy(p->zText, p->zBase, p->nChar+1);
       }else{
-        p->accError = STRACCUM_NOMEM;
+        setStrAccumError(p, STRACCUM_NOMEM);
       }
     }
   }
diff --git a/src/shell.c b/src/shell.c
index 480ec5b45..7826fdf20 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -1836,7 +1836,7 @@ static void csv_append_char(CSVReader *p, int c){
 **   +  Report syntax errors on stderr
 */
 static char *csv_read_one_field(CSVReader *p){
-  int c, pc;
+  int c, pc, ppc;
   int cSep = p->cSeparator;
   p->n = 0;
   c = fgetc(p->in);
@@ -1847,7 +1847,7 @@ static char *csv_read_one_field(CSVReader *p){
   if( c=='"' ){
     int startLine = p->nLine;
     int cQuote = c;
-    pc = 0;
+    pc = ppc = 0;
     while( 1 ){
       c = fgetc(p->in);
       if( c=='\n' ) p->nLine++;
@@ -1859,7 +1859,7 @@ static char *csv_read_one_field(CSVReader *p){
       }
       if( (c==cSep && pc==cQuote)
        || (c=='\n' && pc==cQuote)
-       || (c=='\n' && pc=='\r' && p->n>=2 && p->z[p->n-2]==cQuote)
+       || (c=='\n' && pc=='\r' && ppc==cQuote)
        || (c==EOF && pc==cQuote)
       ){
         do{ p->n--; }while( p->z[p->n]!=cQuote );
@@ -1877,6 +1877,7 @@ static char *csv_read_one_field(CSVReader *p){
         break;
       }
       csv_append_char(p, c);
+      ppc = pc;
       pc = c;
     }
   }else{
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index f67c42a8c..abb690419 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -486,6 +486,7 @@ int sqlite3_exec(
 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
 #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
 #define SQLITE_READONLY_ROLLBACK       (SQLITE_READONLY | (3<<8))
+#define SQLITE_READONLY_DBMOVED        (SQLITE_READONLY | (4<<8))
 #define SQLITE_ABORT_ROLLBACK          (SQLITE_ABORT | (2<<8))
 #define SQLITE_CONSTRAINT_CHECK        (SQLITE_CONSTRAINT | (1<<8))
 #define SQLITE_CONSTRAINT_COMMITHOOK   (SQLITE_CONSTRAINT | (2<<8))
@@ -553,7 +554,8 @@ int sqlite3_exec(
 ** after reboot following a crash or power loss, the only bytes in a
 ** file that were written at the application level might have changed
 ** and that adjacent bytes, even bytes within the same sector are
-** guaranteed to be unchanged.
+** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
+** flag indicate that a file cannot be deleted when open.
 */
 #define SQLITE_IOCAP_ATOMIC                 0x00000001
 #define SQLITE_IOCAP_ATOMIC512              0x00000002
@@ -784,15 +786,29 @@ struct sqlite3_io_methods {
 ** additional information.
 **
 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
-** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by
-** SQLite and sent to all VFSes in place of a call to the xSync method
-** when the database connection has [PRAGMA synchronous] set to OFF.)^
-** Some specialized VFSes need this signal in order to operate correctly
-** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most 
-** VFSes do not need this signal and should silently ignore this opcode.
-** Applications should not call [sqlite3_file_control()] with this
-** opcode as doing so may disrupt the operation of the specialized VFSes
-** that do require it.  
+** No longer in use.
+**
+** <li>[[SQLITE_FCNTL_SYNC]]
+** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
+** sent to the VFS immediately before the xSync method is invoked on a
+** database file descriptor. Or, if the xSync method is not invoked 
+** because the user has configured SQLite with 
+** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 
+** of the xSync method. In most cases, the pointer argument passed with
+** this file-control is NULL. However, if the database file is being synced
+** as part of a multi-database commit, the argument points to a nul-terminated
+** string containing the transactions master-journal file name. VFSes that 
+** do not need this signal should silently ignore this opcode. Applications 
+** should not call [sqlite3_file_control()] with this opcode as doing so may 
+** disrupt the operation of the specialized VFSes that do require it.  
+**
+** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
+** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
+** and sent to the VFS after a transaction has been committed immediately
+** but before the database is unlocked. VFSes that do not need this signal
+** should silently ignore this opcode. Applications should not call
+** [sqlite3_file_control()] with this opcode as doing so may disrupt the 
+** operation of the specialized VFSes that do require it.  
 **
 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
@@ -916,6 +932,12 @@ struct sqlite3_io_methods {
 ** SQLite stack may generate instances of this file control if
 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
 **
+** <li>[[SQLITE_FCNTL_HAS_MOVED]]
+** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
+** pointer to an integer and it writes a boolean into that integer depending
+** on whether or not the file has been renamed, moved, or deleted since it
+** was first opened.
+**
 ** </ul>
 */
 #define SQLITE_FCNTL_LOCKSTATE               1
@@ -936,6 +958,9 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_TEMPFILENAME           16
 #define SQLITE_FCNTL_MMAP_SIZE              18
 #define SQLITE_FCNTL_TRACE                  19
+#define SQLITE_FCNTL_HAS_MOVED              20
+#define SQLITE_FCNTL_SYNC                   21
+#define SQLITE_FCNTL_COMMIT_PHASETWO        22
 
 /*
 ** CAPI3REF: Mutex Handle
@@ -3952,15 +3977,24 @@ int sqlite3_reset(sqlite3_stmt *pStmt);
 **
 ** ^The fourth parameter, eTextRep, specifies what
 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
-** its parameters.  Every SQL function implementation must be able to work
-** with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
-** more efficient with one encoding than another.  ^An application may
-** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
-** times with the same function but with different values of eTextRep.
+** its parameters.  The application should set this parameter to
+** [SQLITE_UTF16LE] if the function implementation invokes 
+** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
+** implementation invokes [sqlite3_value_text16be()] on an input, or
+** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
+** otherwise.  ^The same SQL function may be registered multiple times using
+** different preferred text encodings, with different implementations for
+** each encoding.
 ** ^When multiple implementations of the same function are available, SQLite
 ** will pick the one that involves the least amount of data conversion.
-** If there is only a single implementation which does not care what text
-** encoding is used, then the fourth argument should be [SQLITE_ANY].
+**
+** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
+** to signal that the function will always return the same result given
+** the same inputs within a single SQL statement.  Most SQL functions are
+** deterministic.  The built-in [random()] SQL function is an example of a
+** function that is not deterministic.  The SQLite query planner is able to
+** perform additional optimizations on deterministic functions, so use
+** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
 **
 ** ^(The fifth parameter is an arbitrary pointer.  The implementation of the
 ** function can gain access to this pointer using [sqlite3_user_data()].)^
@@ -4046,10 +4080,20 @@ int sqlite3_create_function_v2(
 #define SQLITE_UTF16LE        2
 #define SQLITE_UTF16BE        3
 #define SQLITE_UTF16          4    /* Use native byte order */
-#define SQLITE_ANY            5    /* sqlite3_create_function only */
+#define SQLITE_ANY            5    /* Deprecated */
 #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
 
 /*
+** CAPI3REF: Function Flags
+**
+** These constants may be ORed together with the 
+** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
+** to [sqlite3_create_function()], [sqlite3_create_function16()], or
+** [sqlite3_create_function_v2()].
+*/
+#define SQLITE_DETERMINISTIC    0x800
+
+/*
 ** CAPI3REF: Deprecated Functions
 ** DEPRECATED
 **
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 0c4159e62..98dc451a4 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3169,6 +3169,7 @@ const void *sqlite3ValueText(sqlite3_value*, u8);
 int sqlite3ValueBytes(sqlite3_value*, u8);
 void sqlite3ValueSetStr(sqlite3_value*, int, const void *,u8, 
                         void(*)(void*));
+void sqlite3ValueSetNull(sqlite3_value*);
 void sqlite3ValueFree(sqlite3_value*);
 sqlite3_value *sqlite3ValueNew(sqlite3 *);
 char *sqlite3Utf16to8(sqlite3 *, const void*, int, u8);
@@ -3234,6 +3235,7 @@ int sqlite3OpenTempDatabase(Parse *);
 
 void sqlite3StrAccumInit(StrAccum*, char*, int, int);
 void sqlite3StrAccumAppend(StrAccum*,const char*,int);
+void sqlite3StrAccumAppendAll(StrAccum*,const char*);
 void sqlite3AppendSpace(StrAccum*,int);
 char *sqlite3StrAccumFinish(StrAccum*);
 void sqlite3StrAccumReset(StrAccum*);
diff --git a/src/test1.c b/src/test1.c
index e0c16e13a..a96b29866 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -942,9 +942,21 @@ static void ptrChngFunction(
   sqlite3_result_int(context, p1!=p2);
 }
 
+/*
+** This SQL function returns a different answer each time it is called, even if
+** the arguments are the same.
+*/
+static void nondeterministicFunction(
+  sqlite3_context *context, 
+  int argc,  
+  sqlite3_value **argv
+){
+  static int cnt = 0;
+  sqlite3_result_int(context, cnt++);
+}
 
 /*
-** Usage:  sqlite_test_create_function DB
+** Usage:  sqlite3_create_function DB
 **
 ** Call the sqlite3_create_function API on the given database in order
 ** to create a function named "x_coalesce".  This function does the same thing
@@ -973,16 +985,16 @@ static int test_create_function(
     return TCL_ERROR;
   }
   if( getDbPointer(interp, argv[1], &db) ) return TCL_ERROR;
-  rc = sqlite3_create_function(db, "x_coalesce", -1, SQLITE_ANY, 0, 
+  rc = sqlite3_create_function(db, "x_coalesce", -1, SQLITE_UTF8, 0, 
         t1_ifnullFunc, 0, 0);
   if( rc==SQLITE_OK ){
-    rc = sqlite3_create_function(db, "hex8", 1, SQLITE_ANY, 0, 
-          hex8Func, 0, 0);
+    rc = sqlite3_create_function(db, "hex8", 1, SQLITE_UTF8 | SQLITE_DETERMINISTIC,
+          0, hex8Func, 0, 0);
   }
 #ifndef SQLITE_OMIT_UTF16
   if( rc==SQLITE_OK ){
-    rc = sqlite3_create_function(db, "hex16", 1, SQLITE_ANY, 0, 
-          hex16Func, 0, 0);
+    rc = sqlite3_create_function(db, "hex16", 1, SQLITE_UTF16 | SQLITE_DETERMINISTIC,
+          0, hex16Func, 0, 0);
   }
 #endif
   if( rc==SQLITE_OK ){
@@ -994,6 +1006,19 @@ static int test_create_function(
           ptrChngFunction, 0, 0);
   }
 
+  /* Functions counter1() and counter2() have the same implementation - they
+  ** both return an ascending integer with each call.  But counter1() is marked
+  ** as non-deterministic and counter2() is marked as deterministic.
+  */
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "counter1", -1, SQLITE_UTF8,
+          0, nondeterministicFunction, 0, 0);
+  }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "counter2", -1, SQLITE_UTF8|SQLITE_DETERMINISTIC,
+          0, nondeterministicFunction, 0, 0);
+  }
+
 #ifndef SQLITE_OMIT_UTF16
   /* Use the sqlite3_create_function16() API here. Mainly for fun, but also 
   ** because it is not tested anywhere else. */
diff --git a/src/test6.c b/src/test6.c
index 6ea03b0f1..306482dcd 100644
--- a/src/test6.c
+++ b/src/test6.c
@@ -173,9 +173,6 @@ static void *crash_realloc(void *p, int n){
 static int writeDbFile(CrashFile *p, u8 *z, i64 iAmt, i64 iOff){
   int rc = SQLITE_OK;
   int iSkip = 0;
-  if( iOff==PENDING_BYTE && (p->flags&SQLITE_OPEN_MAIN_DB) ){
-    iSkip = 512;
-  }
   if( (iAmt-iSkip)>0 ){
     rc = sqlite3OsWrite(p->pRealFile, &z[iSkip], (int)(iAmt-iSkip), iOff+iSkip);
   }
@@ -409,13 +406,17 @@ static int cfRead(
   sqlite_int64 iOfst
 ){
   CrashFile *pCrash = (CrashFile *)pFile;
+  int nCopy = (int)MIN((i64)iAmt, (pCrash->iSize - iOfst));
+
+  if( nCopy>0 ){
+    memcpy(zBuf, &pCrash->zData[iOfst], nCopy);
+  }
 
   /* Check the file-size to see if this is a short-read */
-  if( pCrash->iSize<(iOfst+iAmt) ){
+  if( nCopy<iAmt ){
     return SQLITE_IOERR_SHORT_READ;
   }
 
-  memcpy(zBuf, &pCrash->zData[iOfst], iAmt);
   return SQLITE_OK;
 }
 
@@ -632,14 +633,12 @@ static int cfOpen(
       ** UPDATE: It also contains an assert() verifying that each call
       ** to the xRead() method reads less than 128KB of data.
       */
-      const int isDb = (flags&SQLITE_OPEN_MAIN_DB);
       i64 iOff;
 
       memset(pWrapper->zData, 0, pWrapper->nData);
       for(iOff=0; iOff<pWrapper->iSize; iOff += 512){
         int nRead = (int)(pWrapper->iSize - iOff);
         if( nRead>512 ) nRead = 512;
-        if( isDb && iOff==PENDING_BYTE ) continue;
         rc = sqlite3OsRead(pReal, &pWrapper->zData[iOff], nRead, iOff);
       }
     }else{
diff --git a/src/test_vfstrace.c b/src/test_vfstrace.c
index 0aacc01fe..c1792f116 100644
--- a/src/test_vfstrace.c
+++ b/src/test_vfstrace.c
@@ -258,6 +258,11 @@ static void vfstrace_print_errcode(
     case SQLITE_IOERR_SHMOPEN:      zVal = "SQLITE_IOERR_SHMOPEN";      break;
     case SQLITE_IOERR_SHMSIZE:      zVal = "SQLITE_IOERR_SHMSIZE";      break;
     case SQLITE_IOERR_SHMLOCK:      zVal = "SQLITE_IOERR_SHMLOCK";      break;
+    case SQLITE_IOERR_SHMMAP:       zVal = "SQLITE_IOERR_SHMMAP";       break;
+    case SQLITE_IOERR_SEEK:         zVal = "SQLITE_IOERR_SEEK";         break;
+    case SQLITE_IOERR_GETTEMPPATH:  zVal = "SQLITE_IOERR_GETTEMPPATH";  break;
+    case SQLITE_IOERR_CONVPATH:     zVal = "SQLITE_IOERR_CONVPATH";     break;
+    case SQLITE_READONLY_DBMOVED:   zVal = "SQLITE_READONLY_DBMOVED";   break;
     case SQLITE_LOCKED_SHAREDCACHE: zVal = "SQLITE_LOCKED_SHAREDCACHE"; break;
     case SQLITE_BUSY_RECOVERY:      zVal = "SQLITE_BUSY_RECOVERY";      break;
     case SQLITE_CANTOPEN_NOTEMPDIR: zVal = "SQLITE_CANTOPEN_NOTEMPDIR"; break;
diff --git a/src/util.c b/src/util.c
index 9fa2a0fbd..362a5d897 100644
--- a/src/util.c
+++ b/src/util.c
@@ -115,18 +115,17 @@ int sqlite3Strlen30(const char *z){
 ** to NULL.
 */
 void sqlite3Error(sqlite3 *db, int err_code, const char *zFormat, ...){
-  if( db && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
-    db->errCode = err_code;
-    if( zFormat ){
-      char *z;
-      va_list ap;
-      va_start(ap, zFormat);
-      z = sqlite3VMPrintf(db, zFormat, ap);
-      va_end(ap);
-      sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
-    }else{
-      sqlite3ValueSetStr(db->pErr, 0, 0, SQLITE_UTF8, SQLITE_STATIC);
-    }
+  assert( db!=0 );
+  db->errCode = err_code;
+  if( zFormat && (db->pErr || (db->pErr = sqlite3ValueNew(db))!=0) ){
+    char *z;
+    va_list ap;
+    va_start(ap, zFormat);
+    z = sqlite3VMPrintf(db, zFormat, ap);
+    va_end(ap);
+    sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC);
+  }else if( db->pErr ){
+    sqlite3ValueSetNull(db->pErr);
   }
 }
 
diff --git a/src/vdbe.c b/src/vdbe.c
index 908e5bcb3..e35e324fa 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2506,7 +2506,7 @@ case OP_Column: {
   pDest->enc = encoding;
 
 op_column_out:
-  rc = sqlite3VdbeMemMakeWriteable(pDest);
+  Deephemeralize(pDest);
 op_column_error:
   UPDATE_MAX_BLOBSIZE(pDest);
   REGISTER_TRACE(pOp->p3, pDest);
@@ -2570,7 +2570,8 @@ case OP_MakeRecord: {
   int nField;            /* Number of fields in the record */
   char *zAffinity;       /* The affinity string for the record */
   int file_format;       /* File format to use for encoding */
-  int i;                 /* Space used in zNewRecord[] */
+  int i;                 /* Space used in zNewRecord[] header */
+  int j;                 /* Space used in zNewRecord[] content */
   int len;               /* Length of a field */
 
   /* Assuming the record contains N fields, the record format looks
@@ -2604,36 +2605,51 @@ case OP_MakeRecord: {
   pOut = &aMem[pOp->p3];
   memAboutToChange(p, pOut);
 
+  /* Apply the requested affinity to all inputs
+  */
+  assert( pData0<=pLast );
+  if( zAffinity ){
+    pRec = pData0;
+    do{
+      applyAffinity(pRec, *(zAffinity++), encoding);
+    }while( (++pRec)<=pLast );
+  }
+
   /* Loop through the elements that will make up the record to figure
   ** out how much space is required for the new record.
   */
-  for(pRec=pData0; pRec<=pLast; pRec++){
+  pRec = pLast;
+  do{
     assert( memIsValid(pRec) );
-    if( zAffinity ){
-      applyAffinity(pRec, zAffinity[pRec-pData0], encoding);
-    }
-    if( pRec->flags&MEM_Zero && pRec->n>0 ){
-      sqlite3VdbeMemExpandBlob(pRec);
-    }
     serial_type = sqlite3VdbeSerialType(pRec, file_format);
     len = sqlite3VdbeSerialTypeLen(serial_type);
-    nData += len;
-    nHdr += sqlite3VarintLen(serial_type);
     if( pRec->flags & MEM_Zero ){
-      /* Only pure zero-filled BLOBs can be input to this Opcode.
-      ** We do not allow blobs with a prefix and a zero-filled tail. */
-      nZero += pRec->u.nZero;
-    }else if( len ){
-      nZero = 0;
+      if( nData ){
+        sqlite3VdbeMemExpandBlob(pRec);
+      }else{
+        nZero += pRec->u.nZero;
+        len -= pRec->u.nZero;
+      }
     }
-  }
+    nData += len;
+    testcase( serial_type==127 );
+    testcase( serial_type==128 );
+    nHdr += serial_type<=127 ? 1 : sqlite3VarintLen(serial_type);
+  }while( (--pRec)>=pData0 );
 
   /* Add the initial header varint and total the size */
-  nHdr += nVarint = sqlite3VarintLen(nHdr);
-  if( nVarint<sqlite3VarintLen(nHdr) ){
-    nHdr++;
+  testcase( nHdr==126 );
+  testcase( nHdr==127 );
+  if( nHdr<=126 ){
+    /* The common case */
+    nHdr += 1;
+  }else{
+    /* Rare case of a really large header */
+    nVarint = sqlite3VarintLen(nHdr);
+    nHdr += nVarint;
+    if( nVarint<sqlite3VarintLen(nHdr) ) nHdr++;
   }
-  nByte = nHdr+nData-nZero;
+  nByte = nHdr+nData;
   if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){
     goto too_big;
   }
@@ -2650,14 +2666,16 @@ case OP_MakeRecord: {
 
   /* Write the record */
   i = putVarint32(zNewRecord, nHdr);
-  for(pRec=pData0; pRec<=pLast; pRec++){
+  j = nHdr;
+  assert( pData0<=pLast );
+  pRec = pData0;
+  do{
     serial_type = sqlite3VdbeSerialType(pRec, file_format);
-    i += putVarint32(&zNewRecord[i], serial_type);      /* serial type */
-  }
-  for(pRec=pData0; pRec<=pLast; pRec++){  /* serial data */
-    i += sqlite3VdbeSerialPut(&zNewRecord[i], (int)(nByte-i), pRec,file_format);
-  }
-  assert( i==nByte );
+    i += putVarint32(&zNewRecord[i], serial_type);            /* serial type */
+    j += sqlite3VdbeSerialPut(&zNewRecord[j], pRec, serial_type); /* content */
+  }while( (++pRec)<=pLast );
+  assert( i==nHdr );
+  assert( j==nByte );
 
   assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
   pOut->n = (int)nByte;
@@ -2686,6 +2704,7 @@ case OP_Count: {         /* out2-prerelease */
 
   pCrsr = p->apCsr[pOp->p1]->pCursor;
   assert( pCrsr );
+  nEntry = 0;  /* Not needed.  Only used to silence a warning. */
   rc = sqlite3BtreeCount(pCrsr, &nEntry);
   pOut->u.i = nEntry;
   break;
@@ -3706,7 +3725,6 @@ case OP_Found: {        /* jump, in3 */
   if( pOp->opcode!=OP_NoConflict ) sqlite3_found_count++;
 #endif
 
-  alreadyExists = 0;
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
   assert( pOp->p4type==P4_INT32 );
   pC = p->apCsr[pOp->p1];
@@ -3714,6 +3732,7 @@ case OP_Found: {        /* jump, in3 */
   pIn3 = &aMem[pOp->p3];
   assert( pC->pCursor!=0 );
   assert( pC->isTable==0 );
+  pFree = 0;  /* Not needed.  Only used to suppress a compiler warning. */
   if( pOp->p4.i>0 ){
     r.pKeyInfo = pC->pKeyInfo;
     r.nField = (u16)pOp->p4.i;
@@ -4697,6 +4716,7 @@ case OP_IdxRowid: {              /* out2-prerelease */
   assert( pC->deferredMoveto==0 );
   assert( pC->isTable==0 );
   if( !pC->nullRow ){
+    rowid = 0;  /* Not needed.  Only used to silence a warning. */
     rc = sqlite3VdbeIdxRowid(db, pCrsr, &rowid);
     if( rc!=SQLITE_OK ){
       goto abort_due_to_error;
@@ -4760,6 +4780,7 @@ case OP_IdxGE: {        /* jump */
 #ifdef SQLITE_DEBUG
   { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
 #endif
+  res = 0;  /* Not needed.  Only used to silence a warning. */
   rc = sqlite3VdbeIdxKeyCompare(pC, &r, &res);
   if( pOp->opcode==OP_IdxLT ){
     res = -res;
@@ -4820,6 +4841,7 @@ case OP_Destroy: {     /* out2-prerelease */
     iDb = pOp->p3;
     assert( iCnt==1 );
     assert( (p->btreeMask & (((yDbMask)1)<<iDb))!=0 );
+    iMoved = 0;  /* Not needed.  Only to silence a warning. */
     rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);
     pOut->flags = MEM_Int;
     pOut->u.i = iMoved;
@@ -5392,7 +5414,6 @@ case OP_FkIfZero: {         /* jump */
 ** an integer.
 */
 case OP_MemMax: {        /* in2 */
-  Mem *pIn1;
   VdbeFrame *pFrame;
   if( p->pFrame ){
     for(pFrame=p->pFrame; pFrame->pParent; pFrame=pFrame->pParent);
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index cf1041887..0f89c3a24 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -408,7 +408,7 @@ void sqlite3VdbePrintOp(FILE*, int, Op*);
 #endif
 u32 sqlite3VdbeSerialTypeLen(u32);
 u32 sqlite3VdbeSerialType(Mem*, int);
-u32 sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
+u32 sqlite3VdbeSerialPut(unsigned char*, Mem*, u32);
 u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
 void sqlite3VdbeDeleteAuxData(Vdbe*, int, int);
 
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 976a4125e..080eee3fe 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -486,7 +486,7 @@ int sqlite3_step(sqlite3_stmt *pStmt){
     v->doingRerun = 1;
     assert( v->expired==0 );
   }
-  if( rc2!=SQLITE_OK && ALWAYS(v->isPrepareV2) && ALWAYS(db->pErr) ){
+  if( rc2!=SQLITE_OK ){
     /* This case occurs after failing to recompile an sql statement. 
     ** The error message from the SQL compiler has already been loaded 
     ** into the database handle. This block copies the error message 
@@ -496,6 +496,7 @@ int sqlite3_step(sqlite3_stmt *pStmt){
     ** sqlite3_errmsg() and sqlite3_errcode().
     */
     const char *zErr = (const char *)sqlite3_value_text(db->pErr); 
+    assert( zErr!=0 || db->mallocFailed );
     sqlite3DbFree(db, v->zErrMsg);
     if( !db->mallocFailed ){
       v->zErrMsg = sqlite3DbStrDup(db, zErr);
@@ -1332,6 +1333,7 @@ static UnpackedRecord *vdbeUnpackRecord(
 
   pRet = sqlite3VdbeAllocUnpackedRecord(pKeyInfo, 0, 0, &dummy);
   if( pRet ){
+    memset(pRet->aMem, 0, sizeof(Mem)*(pKeyInfo->nField+1));
     sqlite3VdbeRecordUnpack(pKeyInfo, nKey, pKey, pRet);
   }
   return pRet;
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index c1a22b207..5fc7a3198 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2421,6 +2421,7 @@ int sqlite3VdbeTransferError(Vdbe *p){
   if( p->zErrMsg ){
     u8 mallocFailed = db->mallocFailed;
     sqlite3BeginBenignMalloc();
+    if( db->pErr==0 ) db->pErr = sqlite3ValueNew(db);
     sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
     sqlite3EndBenignMalloc();
     db->mallocFailed = mallocFailed;
@@ -2489,8 +2490,7 @@ int sqlite3VdbeReset(Vdbe *p){
     ** to sqlite3_step(). For consistency (since sqlite3_step() was
     ** called), set the database error in this case as well.
     */
-    sqlite3Error(db, p->rc, 0);
-    sqlite3ValueSetStr(db->pErr, -1, p->zErrMsg, SQLITE_UTF8, SQLITE_TRANSIENT);
+    sqlite3Error(db, p->rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);
     sqlite3DbFree(db, p->zErrMsg);
     p->zErrMsg = 0;
   }
@@ -2828,21 +2828,15 @@ static u64 floatSwap(u64 in){
 ** buf. It is assumed that the caller has allocated sufficient space.
 ** Return the number of bytes written.
 **
-** nBuf is the amount of space left in buf[].  nBuf must always be
-** large enough to hold the entire field.  Except, if the field is
-** a blob with a zero-filled tail, then buf[] might be just the right
-** size to hold everything except for the zero-filled tail.  If buf[]
-** is only big enough to hold the non-zero prefix, then only write that
-** prefix into buf[].  But if buf[] is large enough to hold both the
-** prefix and the tail then write the prefix and set the tail to all
-** zeros.
+** nBuf is the amount of space left in buf[].  The caller is responsible
+** for allocating enough space to buf[] to hold the entire field, exclusive
+** of the pMem->u.nZero bytes for a MEM_Zero value.
 **
 ** Return the number of bytes actually written into buf[].  The number
 ** of bytes in the zero-filled tail is included in the return value only
 ** if those bytes were zeroed in buf[].
 */ 
-u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
-  u32 serial_type = sqlite3VdbeSerialType(pMem, file_format);
+u32 sqlite3VdbeSerialPut(u8 *buf, Mem *pMem, u32 serial_type){
   u32 len;
 
   /* Integer and Real */
@@ -2857,7 +2851,6 @@ u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
       v = pMem->u.i;
     }
     len = i = sqlite3VdbeSerialTypeLen(serial_type);
-    assert( len<=(u32)nBuf );
     while( i-- ){
       buf[i] = (u8)(v&0xFF);
       v >>= 8;
@@ -2869,17 +2862,8 @@ u32 sqlite3VdbeSerialPut(u8 *buf, int nBuf, Mem *pMem, int file_format){
   if( serial_type>=12 ){
     assert( pMem->n + ((pMem->flags & MEM_Zero)?pMem->u.nZero:0)
              == (int)sqlite3VdbeSerialTypeLen(serial_type) );
-    assert( pMem->n<=nBuf );
     len = pMem->n;
     memcpy(buf, pMem->z, len);
-    if( pMem->flags & MEM_Zero ){
-      len += pMem->u.nZero;
-      assert( nBuf>=0 );
-      if( len > (u32)nBuf ){
-        len = (u32)nBuf;
-      }
-      memset(&buf[pMem->n], 0, len-pMem->n);
-    }
     return len;
   }
 
diff --git a/src/vdbemem.c b/src/vdbemem.c
index 51f20d4cc..3beccd92d 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -59,18 +59,14 @@ int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 
 /*
 ** Make sure pMem->z points to a writable allocation of at least 
-** n bytes.
+** min(n,32) bytes.
 **
-** If the third argument passed to this function is true, then memory
-** cell pMem must contain a string or blob. In this case the content is
-** preserved. Otherwise, if the third parameter to this function is false,
-** any current string or blob value may be discarded.
-**
-** This function sets the MEM_Dyn flag and clears any xDel callback.
-** It also clears MEM_Ephem and MEM_Static. If the preserve flag is 
-** not set, Mem.n is zeroed.
+** If the bPreserve argument is true, then copy of the content of
+** pMem->z into the new allocation.  pMem must be either a string or
+** blob if bPreserve is true.  If bPreserve is false, any prior content
+** in pMem->z is discarded.
 */
-int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
+int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
   assert( 1 >=
     ((pMem->zMalloc && pMem->zMalloc==pMem->z) ? 1 : 0) +
     (((pMem->flags&MEM_Dyn)&&pMem->xDel) ? 1 : 0) + 
@@ -79,37 +75,39 @@ int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
   );
   assert( (pMem->flags&MEM_RowSet)==0 );
 
-  /* If the preserve flag is set to true, then the memory cell must already
+  /* If the bPreserve flag is set to true, then the memory cell must already
   ** contain a valid string or blob value.  */
-  assert( preserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
+  assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
+  testcase( bPreserve && pMem->z==0 );
 
-  if( n<32 ) n = 32;
-  if( sqlite3DbMallocSize(pMem->db, pMem->zMalloc)<n ){
-    if( preserve && pMem->z==pMem->zMalloc ){
+  if( pMem->zMalloc==0 || sqlite3DbMallocSize(pMem->db, pMem->zMalloc)<n ){
+    if( n<32 ) n = 32;
+    if( bPreserve && pMem->z==pMem->zMalloc ){
       pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
-      preserve = 0;
+      bPreserve = 0;
     }else{
       sqlite3DbFree(pMem->db, pMem->zMalloc);
       pMem->zMalloc = sqlite3DbMallocRaw(pMem->db, n);
     }
+    if( pMem->zMalloc==0 ){
+      sqlite3VdbeMemRelease(pMem);
+      pMem->flags = MEM_Null;  
+      return SQLITE_NOMEM;
+    }
   }
 
-  if( pMem->z && preserve && pMem->zMalloc && pMem->z!=pMem->zMalloc ){
+  if( pMem->z && bPreserve && pMem->z!=pMem->zMalloc ){
     memcpy(pMem->zMalloc, pMem->z, pMem->n);
   }
-  if( pMem->flags&MEM_Dyn && pMem->xDel ){
+  if( (pMem->flags&MEM_Dyn)!=0 && pMem->xDel ){
     assert( pMem->xDel!=SQLITE_DYNAMIC );
     pMem->xDel((void *)(pMem->z));
   }
 
   pMem->z = pMem->zMalloc;
-  if( pMem->z==0 ){
-    pMem->flags = MEM_Null;
-  }else{
-    pMem->flags &= ~(MEM_Ephem|MEM_Static);
-  }
+  pMem->flags &= ~(MEM_Ephem|MEM_Static);
   pMem->xDel = 0;
-  return (pMem->z ? SQLITE_OK : SQLITE_NOMEM);
+  return SQLITE_OK;
 }
 
 /*
@@ -295,10 +293,12 @@ void sqlite3VdbeMemReleaseExternal(Mem *p){
 */
 void sqlite3VdbeMemRelease(Mem *p){
   VdbeMemRelease(p);
-  sqlite3DbFree(p->db, p->zMalloc);
+  if( p->zMalloc ){
+    sqlite3DbFree(p->db, p->zMalloc);
+    p->zMalloc = 0;
+  }
   p->z = 0;
-  p->zMalloc = 0;
-  p->xDel = 0;
+  assert( p->xDel==0 );  /* Zeroed by VdbeMemRelease() above */
 }
 
 /*
@@ -482,6 +482,9 @@ void sqlite3VdbeMemSetNull(Mem *pMem){
   MemSetTypeFlag(pMem, MEM_Null);
   pMem->type = SQLITE_NULL;
 }
+void sqlite3ValueSetNull(sqlite3_value *p){
+  sqlite3VdbeMemSetNull((Mem*)p); 
+}
 
 /*
 ** Delete any previous value and set the value to be a BLOB of length
@@ -1219,7 +1222,7 @@ static void recordFunc(
   }else{
     aRet[0] = nSerial+1;
     sqlite3PutVarint(&aRet[1], iSerial);
-    sqlite3VdbeSerialPut(&aRet[1+nSerial], nVal, argv[0], file_format);
+    sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);
     sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
     sqlite3DbFree(db, aRet);
   }
diff --git a/src/vdbetrace.c b/src/vdbetrace.c
index 0a767261f..a7ff0a685 100644
--- a/src/vdbetrace.c
+++ b/src/vdbetrace.c
@@ -92,6 +92,7 @@ char *sqlite3VdbeExpandSql(
       const char *zStart = zRawSql;
       while( *(zRawSql++)!='\n' && *zRawSql );
       sqlite3StrAccumAppend(&out, "-- ", 3);
+      assert( (zRawSql - zStart) > 0 );
       sqlite3StrAccumAppend(&out, zStart, (int)(zRawSql-zStart));
     }
   }else{
diff --git a/src/where.c b/src/where.c
index 7d3ec48da..afe664aa0 100644
--- a/src/where.c
+++ b/src/where.c
@@ -2568,7 +2568,7 @@ static void explainAppendTerm(
   const char *zOp             /* Name of the operator */
 ){
   if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5);
-  sqlite3StrAccumAppend(pStr, zColumn, -1);
+  sqlite3StrAccumAppendAll(pStr, zColumn);
   sqlite3StrAccumAppend(pStr, zOp, 1);
   sqlite3StrAccumAppend(pStr, "?", 1);
 }
@@ -2614,7 +2614,7 @@ static char *explainIndexRange(sqlite3 *db, WhereLoop *pLoop, Table *pTab){
     }else{
       if( i ) sqlite3StrAccumAppend(&txt, " AND ", 5);
       sqlite3StrAccumAppend(&txt, "ANY(", 4);
-      sqlite3StrAccumAppend(&txt, z, -1);
+      sqlite3StrAccumAppendAll(&txt, z);
       sqlite3StrAccumAppend(&txt, ")", 1);
     }
   }