Index: src/sqlite.h.in
==================================================================
--- src/sqlite.h.in
+++ src/sqlite.h.in
@@ -28,11 +28,11 @@
 ** The name of this file under configuration management is "sqlite.h.in".
 ** The makefile makes some minor changes to this file (such as inserting
 ** the version number) and changes its name to "sqlite3.h" as
 ** part of the build process.
 **
-** @(#) $Id: sqlite.h.in,v 1.276 2007/12/06 02:42:08 drh Exp $
+** @(#) $Id: sqlite.h.in,v 1.277 2007/12/12 12:25:22 drh Exp $
 */
 #ifndef _SQLITE3_H_
 #define _SQLITE3_H_
 #include <stdarg.h>     /* Needed for the definition of va_list */
 
@@ -296,11 +296,11 @@
 **
 */
 #define SQLITE_OK           0   /* Successful result */
 /* beginning-of-error-codes */
 #define SQLITE_ERROR        1   /* SQL error or missing database */
-#define SQLITE_INTERNAL     2   /* NOT USED. Internal logic error in SQLite */
+#define SQLITE_INTERNAL     2   /* Internal logic error in SQLite */
 #define SQLITE_PERM         3   /* Access permission denied */
 #define SQLITE_ABORT        4   /* Callback routine requested an abort */
 #define SQLITE_BUSY         5   /* The database file is locked */
 #define SQLITE_LOCKED       6   /* A table in the database is locked */
 #define SQLITE_NOMEM        7   /* A malloc() failed */

Index: src/update.c
==================================================================
--- src/update.c
+++ src/update.c
@@ -10,11 +10,11 @@
 **
 *************************************************************************
 ** This file contains C code routines that are called by the parser
 ** to handle UPDATE statements.
 **
-** $Id: update.c,v 1.142 2007/12/12 12:00:46 drh Exp $
+** $Id: update.c,v 1.143 2007/12/12 12:25:22 drh Exp $
 */
 #include "sqliteInt.h"
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 /* Forward declaration */
@@ -103,10 +103,11 @@
   int openAll = 0;       /* True if all indices need to be opened */
   AuthContext sContext;  /* The authorization context */
   NameContext sNC;       /* The name-context to resolve expressions in */
   int iDb;               /* Database containing the table being updated */
   int memCnt = 0;        /* Memory cell used for counting rows changed */
+  int mem1;      /* Memory address storing the rowid for next row to update */
 
 #ifndef SQLITE_OMIT_TRIGGER
   int isView;                  /* Trying to update a view */
   int triggers_exist = 0;      /* True if any row triggers exist */
 #endif
@@ -259,10 +260,11 @@
   */
   v = sqlite3GetVdbe(pParse);
   if( v==0 ) goto update_cleanup;
   if( pParse->nested==0 ) sqlite3VdbeCountChanges(v);
   sqlite3BeginWriteOperation(pParse, 1, iDb);
+  mem1 = pParse->nMem++;
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   /* Virtual tables must be handled separately */
   if( IsVirtual(pTab) ){
     updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef,
@@ -316,11 +318,10 @@
     memCnt = pParse->nMem++;
     sqlite3VdbeAddOp(v, OP_MemInt, 0, memCnt);
   }
 
   if( triggers_exist ){
-    int mem1;      /* Memory address storing the rowid for next row to update */
     
     /* Create pseudo-tables for NEW and OLD
     */
     sqlite3VdbeAddOp(v, OP_OpenPseudo, oldIdx, 0);
     sqlite3VdbeAddOp(v, OP_SetNumColumns, oldIdx, pTab->nCol);
@@ -329,11 +330,10 @@
 
     /* The top of the update loop for when there are triggers.
     */
     addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
     sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
-    mem1 = pParse->nMem++;
     sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
     
     if( !isView ){
       /* Open a cursor and make it point to the record that is
       ** being updated.
@@ -385,11 +385,10 @@
       goto update_cleanup;
     }
     
     if( !isView ){
       sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
-      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
     }
   }
 
   if( !isView && !IsVirtual(pTab) ){
     /* 
@@ -427,13 +426,14 @@
     ** So make the cursor point at the old record.
     */
     if( !triggers_exist ){
       addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, 0);
       sqlite3VdbeAddOp(v, OP_StackDepth, -1, 0);
-      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
+      sqlite3VdbeAddOp(v, OP_MemStore, mem1, 0);
     }
     sqlite3VdbeAddOp(v, OP_NotExists, iCur, addr);
+    sqlite3VdbeAddOp(v, OP_MemLoad, mem1, 0);
 
     /* If the record number will change, push the record number as it
     ** will be after the update. (The old record number is currently
     ** on top of the stack.)
     */

Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -41,11 +41,11 @@
 ** documentation, headers files, or other derived files.  The formatting
 ** of the code in this file is, therefore, important.  See other comments
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.657 2007/12/12 12:00:46 drh Exp $
+** $Id: vdbe.c,v 1.658 2007/12/12 12:25:22 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
 #include "vdbeInt.h"
 
@@ -703,14 +703,14 @@
 case OP_StackDepth: {       /* no-push */
   if( pOp->p1<0 ){
     pOp->p1 = pTos - p->aStack + 1;
   }else if( pOp->p1!=pTos - p->aStack + 1 ){
     p->pTos = pTos;
-    p->rc = SQLITE_ERROR;
+    p->rc = rc = SQLITE_INTERNAL;
     p->pc = pc;
     p->errorAction = OE_Rollback;
-    sqlite3SetString(&p->zErrMsg, "internal VDBE stack overflow", (char*)0);
+    sqlite3SetString(&p->zErrMsg, "internal error: VDBE stack leak", (char*)0);
     goto vdbe_return;
   }
   break;
 }