From: danielk1977 <danielk1977@noemail.net>
Date: Wed, 18 Jan 2006 15:25:17 +0000 (+0000)
Subject: Change sqlite3MallocClearFailed() calls to sqlite3ApiExit(), a better API. (CVS 2970)
X-Git-Tag: version-3.6.10~3197
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=54f0198e47ef06ee7a4326ccc51d6a21ce8914d2;p=thirdparty%2Fsqlite.git

Change sqlite3MallocClearFailed() calls to sqlite3ApiExit(), a better API. (CVS 2970)

FossilOrigin-Name: e0b022e5b2bfd272b4e25cd7a7b472206a118bbe
---

diff --git a/manifest b/manifest
index d7edeadf21..fbab084397 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Recursive\smutexes\sin\sos_win.c.\s(CVS\s2969)
-D 2006-01-18T14:20:17
+C Change\ssqlite3MallocClearFailed()\scalls\sto\ssqlite3ApiExit(),\sa\sbetter\sAPI.\s(CVS\s2970)
+D 2006-01-18T15:25:17
 F Makefile.in ab3ffd8d469cef4477257169b82810030a6bb967
 F Makefile.linux-gcc aee18d8a05546dcf1888bd4547e442008a49a092
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -34,11 +34,11 @@ F src/alter.c f1b66e9a6d606450d6e8fc23e2a96cd84666fdd3
 F src/analyze.c 7d2b7ab9a9c2fd6e55700f69064dfdd3e36d7a8a
 F src/attach.c a447b4672a5125abc4ee27df10621abd84d18301
 F src/auth.c 9ae84d2d94eb96195e04515715e08e85963e96c2
-F src/btree.c fcf6aec3b6a6df8130213a45f7b543e0a025be9d
+F src/btree.c cff3ab167ad25b394d8c8dcac783bf3db5ae7e31
 F src/btree.h 5663c4f43e8521546ccebc8fc95acb013b8f3184
 F src/build.c 539b5c6e21aa633e480ff97706f331baef1a859a
 F src/callback.c ba3e6cc7a6beb562e7a66f92e26fabcb21aab1e2
-F src/complete.c df1681cef40dec33a286006981845f87b194e7a4
+F src/complete.c 7d1a44be8f37de125fcafd3d3a018690b3799675
 F src/date.c 2f148728b53675266cd9e1a873fd702929d3f4ee
 F src/delete.c c7bd5708a629585e073ce34cf3b1fcb52c2fef38
 F src/experimental.c 50c1e3b34f752f4ac10c36f287db095c2b61766d
@@ -47,30 +47,30 @@ F src/func.c 96b26601c092b7b43a13e440e3f988b32a385f6a
 F src/hash.c 8747cf51d12de46512880dfcf1b68b4e24072863
 F src/hash.h 1b0c445e1c89ff2aaad9b4605ba61375af001e84
 F src/insert.c a5595cf8d1d8ba087b676a63f1f7277ea44b5ac1
-F src/legacy.c 9bf7ee1b63c99aac6669533986a5240b16101458
-F src/main.c fd9cb79c9fb6c61a67ad8be19a782372b0c4f48d
+F src/legacy.c 0fd27db5e07a46853b9876baaa370b40e75a9b40
+F src/main.c bf810309d9760654f58c77688524d2a556b2827c
 F src/md5.c c5fdfa5c2593eaee2e32a5ce6c6927c986eaf217
 F src/os.c 1d1a61cdf150e9f9520a3bc787c8465148ea2e78
 F src/os.h 9debc3d3ca4cdafde222a0ea74a4c8415aef4f22
 F src/os_common.h 95b29ca6f3e6636cb33c9219b3f91a96fa7224b1
 F src/os_test.c 49833426101f99aee4bb5f6a44b7c4b2029fda1c
 F src/os_test.h 903c93554c23d88f34f667f1979e4a1cee792af3
-F src/os_unix.c 7c085f807922309006f00b5fd8963865b92ff939
+F src/os_unix.c fb7ae89d8672102b60e855dae5834f9d1ef7c99c
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c e1c0600129f2468c8a852ae61f7b7bacf72aa7dc
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c e84713f7196a81103cc8e2b55cebbaa1723c4926
+F src/pager.c 62c0f6b4c4856a760d4a7430c88492a7b626ac18
 F src/pager.h e0acb095b3ad0bca48f2ab00c87346665643f64f
 F src/parse.y 83df51fea35f68f7e07384d75dce83d1ed30434c
 F src/pragma.c 4496cc77dc35824e1c978c3d1413b8a5a4c777d3
-F src/prepare.c 84c3cbca337a49133554108d748864c5e13aef34
+F src/prepare.c 1294009215173899f3d64dc16f1dc50edaedbb6a
 F src/printf.c f47a2f4b5387cd2ebb12e9117a1a5d6bd9a2b812
 F src/random.c d40f8d356cecbd351ccfab6eaedd7ec1b54f5261
 F src/select.c 28d449c7762dd580aaba49a9c6c16e93ca951e49
 F src/server.c 087b92a39d883e3fa113cae259d64e4c7438bc96
 F src/shell.c 66b073375efbdee19045e7e0cd38b85f9aff71da
 F src/sqlite.h.in 492580f7e3ff71eb43193eb7bb98e2d549889ce3
-F src/sqliteInt.h d7b20e0a9453db123809d0bcc46d6ae0e4cf6bca
+F src/sqliteInt.h b23caafa3ce3d71f4a0f0e3aa3fb6779eda3a1b7
 F src/table.c 486dcfce532685b53b5a2b5da8bba0ded6fb2316
 F src/tclsqlite.c d650bea0248fc0a310ddc2cb94273a3a5021fddf
 F src/test1.c b076d9c42b547ec0891b67722f00681b21756d91
@@ -85,12 +85,12 @@ F src/tokenize.c 8b694d42b48f22c2037da7e1e716201aaaaa0f3a
 F src/trigger.c 694b247476d2fc0dce003af564f79e8752fc1158
 F src/update.c 261d75c702c2852d1a64274d7c414485e6f2d177
 F src/utf.c 5ab8ca05d4e9ec81174b010f01ab12a232f0087d
-F src/util.c 25e867296bce168095c87460ab5eec150015cb7d
+F src/util.c 28f399a6e3b4b55caf635f1941ee2391072d1a78
 F src/vacuum.c 21a3c7f6f7be86bb1182fbc3df416ad702435b9e
 F src/vdbe.c 3db9bfc86e71dc0758524fb82cfcfd4c30e92716
 F src/vdbe.h 8729a4ee16ff9aeab2af9667df3cf300ff978e13
 F src/vdbeInt.h 5451cf71f229e366ac543607c0a17f36e5737ea9
-F src/vdbeapi.c 2c3068bc5d17f7bd179b346a4a920199ea451694
+F src/vdbeapi.c cbc552ea2d1acca790cfee88bb7e670cf34a054b
 F src/vdbeaux.c 723e0ec773aeec53e9448b2ac5b136677e64ece0
 F src/vdbefifo.c 9efb94c8c3f4c979ebd0028219483f88e57584f5
 F src/vdbemem.c dd08a0eea4868ac4a2d91fdec32424308b1db772
@@ -341,7 +341,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 8830bbbac8e0c9243956aac42dc9f86a0bd1fa07
-R 7ad1313dca6d71746c68d32b98aa5742
-U drh
-Z 25414a8af7b032353ad4c225fe562fb4
+P dd3e07cae4d0cbd4f8977e1dd11e0103e0e45b75
+R baef608325fb18b2b8e10ab8f84cb339
+U danielk1977
+Z 2a85eb76c461ae700bdd874fef6ec61c
diff --git a/manifest.uuid b/manifest.uuid
index 2776453eb9..66b878cc24 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-dd3e07cae4d0cbd4f8977e1dd11e0103e0e45b75
\ No newline at end of file
+e0b022e5b2bfd272b4e25cd7a7b472206a118bbe
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 8674e9c6ed..7a46d26ec3 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.299 2006/01/16 15:14:27 danielk1977 Exp $
+** $Id: btree.c,v 1.300 2006/01/18 15:25:17 danielk1977 Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -1662,7 +1662,11 @@ int sqlite3BtreeOpen(
   sqlite3pager_set_pagesize(pBt->pPager, pBt->pageSize);
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
-  /* Add the new btree to the linked list starting at ThreadData.pBtree */
+  /* Add the new btree to the linked list starting at ThreadData.pBtree.
+  ** There is no chance that a malloc() may fail inside of the 
+  ** sqlite3ThreadData() call, as the ThreadData structure must have already
+  ** been allocated for pTsdro->useSharedData to be non-zero.
+  */
   if( pTsdro->useSharedData && zFilename && !isMemdb ){
     pBt->pNext = pTsdro->pBtree;
     sqlite3ThreadData()->pBtree = pBt;
@@ -1712,14 +1716,19 @@ int sqlite3BtreeClose(Btree *p){
     return SQLITE_OK;
   }
 
-  /* Remove the shared-btree from the thread wide list */
-  pTsd = sqlite3ThreadData();
+  /* Remove the shared-btree from the thread wide list. Call 
+  ** ThreadDataReadOnly() and then cast away the const property of the 
+  ** pointer to avoid allocating thread data if it is not really required.
+  */
+  pTsd = (ThreadData *)sqlite3ThreadDataReadOnly();
   if( pTsd->pBtree==pBt ){
+    assert( pTsd==sqlite3ThreadData() );
     pTsd->pBtree = pBt->pNext;
   }else{
     BtShared *pPrev;
     for(pPrev=pTsd->pBtree; pPrev && pPrev->pNext!=pBt; pPrev=pPrev->pNext);
     if( pPrev ){
+      assert( pTsd==sqlite3ThreadData() );
       pPrev->pNext = pBt->pNext;
     }
   }
diff --git a/src/complete.c b/src/complete.c
index 61a87e57c3..536ffadbc2 100644
--- a/src/complete.c
+++ b/src/complete.c
@@ -16,7 +16,7 @@
 ** separating it out, the code will be automatically omitted from
 ** static links that do not use it.
 **
-** $Id: complete.c,v 1.2 2005/12/12 06:53:04 danielk1977 Exp $
+** $Id: complete.c,v 1.3 2006/01/18 15:25:17 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #ifndef SQLITE_OMIT_COMPLETE
@@ -255,12 +255,9 @@ int sqlite3_complete16(const void *zSql){
   zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8);
   if( zSql8 ){
     rc = sqlite3_complete(zSql8);
-  }else if( zSql ){
-    rc = SQLITE_NOMEM;
-    sqlite3MallocClearFailed();
   }
   sqlite3ValueFree(pVal);
-  return rc;
+  return sqlite3ApiExit(0, rc);
 }
 #endif /* SQLITE_OMIT_UTF16 */
 #endif /* SQLITE_OMIT_COMPLETE */
diff --git a/src/legacy.c b/src/legacy.c
index b149f5b29f..98f37a922a 100644
--- a/src/legacy.c
+++ b/src/legacy.c
@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: legacy.c,v 1.11 2006/01/11 21:41:22 drh Exp $
+** $Id: legacy.c,v 1.12 2006/01/18 15:25:17 danielk1977 Exp $
 */
 
 #include "sqliteInt.h"
@@ -121,11 +121,7 @@ exec_out:
   if( pStmt ) sqlite3_finalize(pStmt);
   if( azCols ) sqliteFree(azCols);
 
-  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
-    rc = SQLITE_NOMEM;
-    sqlite3MallocClearFailed();
-  }
-
+  rc = sqlite3ApiExit(0, rc);
   if( rc!=SQLITE_OK && rc==sqlite3_errcode(db) && pzErrMsg ){
     *pzErrMsg = malloc(1+strlen(sqlite3_errmsg(db)));
     if( *pzErrMsg ){
diff --git a/src/main.c b/src/main.c
index 77fe0710a2..c2822a7e53 100644
--- a/src/main.c
+++ b/src/main.c
@@ -14,7 +14,7 @@
 ** other files are for internal use by SQLite and should not be
 ** accessed by users of the library.
 **
-** $Id: main.c,v 1.326 2006/01/18 05:51:58 danielk1977 Exp $
+** $Id: main.c,v 1.327 2006/01/18 15:25:17 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -485,12 +485,7 @@ int sqlite3_create_function(
   assert( !sqlite3ThreadDataReadOnly()->mallocFailed );
   rc = sqlite3CreateFunc(db, zFunctionName, nArg, enc, p, xFunc, xStep, xFinal);
 
-  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
-    sqlite3MallocClearFailed();
-    rc = SQLITE_NOMEM;
-    sqlite3Error(db, SQLITE_NOMEM, 0);
-  }
-  return rc;
+  return sqlite3ApiExit(db, rc);
 }
 
 #ifndef SQLITE_OMIT_UTF16
@@ -512,12 +507,7 @@ int sqlite3_create_function16(
   rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xFunc, xStep, xFinal);
   sqliteFree(zFunc8);
 
-  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
-    sqlite3MallocClearFailed();
-    rc = SQLITE_NOMEM;
-    sqlite3Error(db, SQLITE_NOMEM, 0);
-  }
-  return rc;
+  return sqlite3ApiExit(db, rc);
 }
 #endif
 
@@ -727,7 +717,7 @@ const void *sqlite3_errmsg16(sqlite3 *db){
          SQLITE_UTF8, SQLITE_STATIC);
     z = sqlite3_value_text16(db->pErr);
   }
-  sqlite3MallocClearFailed();
+  sqlite3ApiExit(0, 0);
   return z;
 }
 #endif /* SQLITE_OMIT_UTF16 */
@@ -835,10 +825,7 @@ static int openDatabase(
       createCollation(db, "BINARY", SQLITE_UTF16, 0,binCollFunc) ||
       (db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 6, 0))==0 
   ){
-    /* sqlite3_create_collation() is an external API. So the mallocFailed flag
-    ** will have been cleared before returning. So set it explicitly here.
-    */
-    sqlite3ThreadData()->mallocFailed = 1;
+    assert( sqlite3ThreadDataReadOnly()->mallocFailed );
     db->magic = SQLITE_MAGIC_CLOSED;
     goto opendb_out;
   }
@@ -895,8 +882,7 @@ opendb_out:
     db = 0;
   }
   *ppDb = db;
-  sqlite3MallocClearFailed();
-  return rc;
+  return sqlite3ApiExit(0, rc);
 }
 
 /*
@@ -918,7 +904,7 @@ int sqlite3_open16(
   sqlite3 **ppDb
 ){
   char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
-  int rc = SQLITE_NOMEM;
+  int rc = SQLITE_OK;
   sqlite3_value *pVal;
 
   assert( zFilename );
@@ -936,13 +922,10 @@ int sqlite3_open16(
         *ppDb = 0;
       }
     }
-  }else{
-    assert( sqlite3ThreadDataReadOnly()->mallocFailed );
-    sqlite3MallocClearFailed();
   }
   sqlite3ValueFree(pVal);
 
-  return rc;
+  return sqlite3ApiExit(0, rc);
 }
 #endif /* SQLITE_OMIT_UTF16 */
 
@@ -997,12 +980,7 @@ int sqlite3_create_collation(
   int rc;
   assert( !sqlite3ThreadDataReadOnly()->mallocFailed );
   rc = createCollation(db, zName, enc, pCtx, xCompare);
-  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
-    sqlite3MallocClearFailed();
-    rc = SQLITE_NOMEM;
-    sqlite3Error(db, rc, 0);
-  }
-  return rc;
+  return sqlite3ApiExit(db, rc);
 }
 
 #ifndef SQLITE_OMIT_UTF16
@@ -1024,12 +1002,7 @@ int sqlite3_create_collation16(
     rc = createCollation(db, zName8, enc, pCtx, xCompare);
     sqliteFree(zName8);
   }
-  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
-    sqlite3MallocClearFailed();
-    rc = SQLITE_NOMEM;
-    sqlite3Error(db, rc, 0);
-  }
-  return rc;
+  return sqlite3ApiExit(db, rc);
 }
 #endif /* SQLITE_OMIT_UTF16 */
 
@@ -1115,6 +1088,9 @@ int sqlite3Corrupt(void){
 */
 int sqlite3_enable_shared_cache(int enable){
   ThreadData *pTd = sqlite3ThreadData();
+  if( !pTd ){
+    return SQLITE_NOMEM;
+  }
   
   /* It is only legal to call sqlite3_enable_shared_cache() when there
   ** are no currently open b-trees that were opened by the calling thread.
@@ -1138,6 +1114,8 @@ int sqlite3_enable_shared_cache(int enable){
 */
 void sqlite3_thread_cleanup(void){
   ThreadData *pTd = sqlite3ThreadData();
-  memset(pTd, 0, sizeof(*pTd));
+  if( pTd ){
+    memset(pTd, 0, sizeof(*pTd));
+  }
   sqlite3ReleaseThreadData();
 }
diff --git a/src/os_unix.c b/src/os_unix.c
index 35d29ad3cf..5257bfd5e3 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -1739,6 +1739,19 @@ int sqlite3_tsd_count = 0;
 # define TSD_COUNTER(N)  /* no-op */
 #endif
 
+#if 0 && defined(SQLITE_MEMDEBUG)
+static void *mallocThreadData(size_t nBytes){
+  if( sqlite3_iMallocFail>=0 ){
+    sqlite3_iMallocFail--;
+    if( sqlite3_iMallocFail==0 ){
+      return 0;
+    }
+  }
+  return sqlite3OsMalloc(nBytes);
+}
+#else
+  #define mallocThreadData(x) sqlite3OsMalloc(x)
+#endif
 
 /*
 ** If called with allocateFlag>0, then return a pointer to thread
@@ -1778,7 +1791,7 @@ ThreadData *sqlite3UnixThreadSpecificData(int allocateFlag){
   pTsd = pthread_getspecific(key);
   if( allocateFlag>0 ){
     if( pTsd==0 ){
-      pTsd = sqlite3OsMalloc(sizeof(zeroData));
+      pTsd = mallocThreadData(sizeof(zeroData));
       if( pTsd ){
         *pTsd = zeroData;
         pthread_setspecific(key, pTsd);
@@ -1797,7 +1810,7 @@ ThreadData *sqlite3UnixThreadSpecificData(int allocateFlag){
   static ThreadData *pTsd = 0;
   if( allocateFlag>0 ){
     if( pTsd==0 ){
-      pTsd = sqlite3OsMalloc( sizeof(zeroData) );
+      pTsd = mallocThreadData( sizeof(zeroData) );
       if( pTsd ){
         *pTsd = zeroData;
         TSD_COUNTER(+1);
diff --git a/src/pager.c b/src/pager.c
index 597e6e0048..0425a4419e 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.241 2006/01/16 15:32:23 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.242 2006/01/18 15:25:17 danielk1977 Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -1577,7 +1577,15 @@ int sqlite3pager_open(
   int noReadlock = (flags & PAGER_NO_READLOCK)!=0;
   char zTemp[SQLITE_TEMPNAME_SIZE];
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  /* A malloc() cannot fail in sqlite3ThreadData() as one or more calls to 
+  ** malloc() must have already been made by this thread before it gets
+  ** to this point. This means the ThreadData must have been allocated already
+  ** so that ThreadData.nAlloc can be set. It would be nice to assert
+  ** that ThreadData.nAlloc is non-zero, but alas this breaks test cases 
+  ** written to invoke the pager directly.
+  */
   ThreadData *pTsd = sqlite3ThreadData();
+  assert( pTsd );
 #endif
 
   /* If malloc() has already failed return SQLITE_NOMEM. Before even
@@ -1985,7 +1993,13 @@ int sqlite3pager_truncate(Pager *pPager, Pgno nPage){
 int sqlite3pager_close(Pager *pPager){
   PgHdr *pPg, *pNext;
 #ifdef SQLITE_ENABLE_MEMORY_MANAGEMENT
+  /* A malloc() cannot fail in sqlite3ThreadData() as one or more calls to 
+  ** malloc() must have already been made by this thread before it gets
+  ** to this point. This means the ThreadData must have been allocated already
+  ** so that ThreadData.nAlloc can be set.
+  */
   ThreadData *pTsd = sqlite3ThreadData();
+  assert( pTsd && pTsd->nAlloc );
 #endif
 
   switch( pPager->state ){
diff --git a/src/prepare.c b/src/prepare.c
index 26dc155b11..cd82f1a319 100644
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -13,7 +13,7 @@
 ** interface, and routines that contribute to loading the database schema
 ** from disk.
 **
-** $Id: prepare.c,v 1.24 2006/01/17 13:21:40 danielk1977 Exp $
+** $Id: prepare.c,v 1.25 2006/01/18 15:25:18 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -570,16 +570,8 @@ int sqlite3_prepare(
     sqlite3Error(db, rc, 0);
   }
 
-  /* We must check for malloc failure last of all, in case malloc() failed
-  ** inside of the sqlite3Error() call above or something.
-  */
-  if( sParse.pTsd->mallocFailed ){
-    rc = SQLITE_NOMEM;
-    sqlite3Error(db, rc, 0);
-  }
-
   sParse.pTsd->nRef--;
-  sqlite3MallocClearFailed();
+  rc = sqlite3ApiExit(db, rc);
   sqlite3ReleaseThreadData();
   return rc;
 }
@@ -599,20 +591,17 @@ int sqlite3_prepare16(
   ** encoded string to UTF-8, then invoking sqlite3_prepare(). The
   ** tricky bit is figuring out the pointer to return in *pzTail.
   */
-  char *zSql8 = 0;
+  char *zSql8;
   const char *zTail8 = 0;
-  int rc;
+  int rc = SQLITE_OK;
 
   if( sqlite3SafetyCheck(db) ){
     return SQLITE_MISUSE;
   }
   zSql8 = sqlite3utf16to8(zSql, nBytes);
-  if( !zSql8 ){
-    sqlite3MallocClearFailed();
-    sqlite3Error(db, SQLITE_NOMEM, 0);
-    return SQLITE_NOMEM;
+  if( zSql8 ){
+    rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8);
   }
-  rc = sqlite3_prepare(db, zSql8, -1, ppStmt, &zTail8);
 
   if( zTail8 && pzTail ){
     /* If sqlite3_prepare returns a tail pointer, we calculate the
@@ -624,6 +613,6 @@ int sqlite3_prepare16(
     *pzTail = (u8 *)zSql + sqlite3utf16ByteLen(zSql, chars_parsed);
   }
   sqliteFree(zSql8); 
-  return rc;
+  return sqlite3ApiExit(db, rc);
 }
 #endif /* SQLITE_OMIT_UTF16 */
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 2c8ea08441..4bb2c14e5e 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.472 2006/01/17 16:10:14 danielk1977 Exp $
+** @(#) $Id: sqliteInt.h,v 1.473 2006/01/18 15:25:18 danielk1977 Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -1765,6 +1765,7 @@ KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
   void (*)(sqlite3_context*,int,sqlite3_value **),
   void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
+int sqlite3ApiExit(sqlite3 *db, int);
 
 #ifndef SQLITE_OMIT_SHARED_CACHE
   void sqlite3TableLock(Parse *, int, int, u8, const char *);
@@ -1772,7 +1773,6 @@ int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
   #define sqlite3TableLock(v,w,x,y,z)
 #endif
 
-void sqlite3MallocClearFailed();
 #ifdef SQLITE_MEMDEBUG
   void sqlite3MallocDisallow();
   void sqlite3MallocAllow();
diff --git a/src/util.c b/src/util.c
index ab7e1420c9..36cf5dc8da 100644
--- a/src/util.c
+++ b/src/util.c
@@ -14,7 +14,7 @@
 ** This file contains functions for allocating memory, comparing
 ** strings, and stuff like that.
 **
-** $Id: util.c,v 1.173 2006/01/17 15:36:32 danielk1977 Exp $
+** $Id: util.c,v 1.174 2006/01/18 15:25:18 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -1336,15 +1336,28 @@ void sqlite3ReleaseThreadData(){
 }
 
 /*
-** Clear the "mallocFailed" flag. This should be invoked before exiting any
-** entry points that may have called sqliteMalloc().
+** This function must be called before exiting any API function (i.e. 
+** returning control to the user) that has called sqlite3Malloc or
+** sqlite3Realloc.
+**
+** The returned value is normally a copy of the second argument to this
+** function. However, if a malloc() failure has occured since the previous
+** invocation SQLITE_NOMEM is returned instead. 
+**
+** If the first argument, db, is not NULL and a malloc() error has occured,
+** then the connection error-code (the value returned by sqlite3_errcode())
+** is set to SQLITE_NOMEM.
 */
-void sqlite3MallocClearFailed(){
+int sqlite3ApiExit(sqlite3* db, int rc){
   ThreadData *pTd = sqlite3OsThreadSpecificData(0);
   if( pTd && pTd->mallocFailed ){
     pTd->mallocFailed = 0;
-    sqlite3OsThreadSpecificData(0);
+    if( db ){
+      sqlite3Error(db, SQLITE_NOMEM, 0);
+    }
+    return SQLITE_NOMEM;
   }
+  return rc;
 }
 
 #ifdef SQLITE_MEMDEBUG
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 5d5ec27f2e..c1ae4806ac 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -242,8 +242,7 @@ int sqlite3_step(sqlite3_stmt *pStmt){
 #endif
 
   sqlite3Error(p->db, rc, p->zErrMsg ? "%s" : 0, p->zErrMsg);
-  sqlite3MallocClearFailed();
-  return rc;
+  return sqlite3ApiExit(p->db, rc);
 }
 
 /*
@@ -405,10 +404,8 @@ static void columnMallocFailure(sqlite3_stmt *pStmt)
   ** SQLITE_NOMEM. The next call to _step() (if any) will return SQLITE_ERROR
   ** and _finalize() will return NOMEM.
   */
-  if( sqlite3ThreadDataReadOnly()->mallocFailed ){
-    ((Vdbe *)pStmt)->rc = SQLITE_NOMEM;
-    sqlite3MallocClearFailed();
-  }
+  Vdbe *p = (Vdbe *)pStmt;
+  p->rc = sqlite3ApiExit(0, p->rc);
 }
 
 /**************************** sqlite3_column_  *******************************
@@ -503,7 +500,7 @@ static const void *columnName(
   /* A malloc may have failed inside of the xFunc() call. If this is the case,
   ** clear the mallocFailed flag and return NULL.
   */
-  sqlite3MallocClearFailed();
+  sqlite3ApiExit(0, 0);
   return ret;
 }
 
@@ -634,9 +631,9 @@ static int bindText(
   if( rc==SQLITE_OK && encoding!=0 ){
     rc = sqlite3VdbeChangeEncoding(pVar, ENC(p->db));
   }
-  sqlite3MallocClearFailed();
+
   sqlite3Error(((Vdbe *)pStmt)->db, rc, 0);
-  return rc;
+  return sqlite3ApiExit(((Vdbe *)pStmt)->db, rc);
 }