Do not incorrectly report a malloc() failure when allocating 0 bytes. Fixes a problem in bind.test. (CVS 4931)

FossilOrigin-Name: b99d19d651b00dcc7bdb36facfd9ecffe4fafd9f

manifest

@@ -1,5 +1,5 @@
-C Fix\sfor\s#3022.\sHandle\squeries\slike\s"SELECT\smin(b)\sFROM\sT\sWHERE\sa\s=\sX\sAND\sb\s>\sX"\swhen\sthere\sis\san\sindex\son\s(a,b).\s(CVS\s4930)
-D 2008-03-28T18:11:17
+C Do\snot\sincorrectly\sreport\sa\smalloc()\sfailure\swhen\sallocating\s0\sbytes.\sFixes\sa\sproblem\sin\sbind.test.\s(CVS\s4931)
+D 2008-03-28T19:15:35
 F Makefile.arm-wince-mingw32ce-gcc ac5f7b2cef0cd850d6f755ba6ee4ab961b1fadf7
 F Makefile.in cf434ce8ca902e69126ae0f94fc9f7dc7428a5fa
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -181,7 +181,7 @@ F src/vdbeapi.c e03b846adf7fb938b3945019dc6c4c49ed86bb0e
 F src/vdbeaux.c 519ec819a8e549d087899f0c9a912afcdda762b4
 F src/vdbeblob.c cc713c142c3d4952b380c98ee035f850830ddbdb
 F src/vdbefifo.c a30c237b2a3577e1415fb6e288cbb6b8ed1e5736
-F src/vdbemem.c 05f231580c528ccb7bef190568453140e79e4a2e
+F src/vdbemem.c e7ced8846ef50502cc610ecc7b32bb0f0bba1578
 F src/vtab.c 00cd16317b29495c185ff40e4b227917d5a371b2
 F src/where.c aa7ca84521e44925a5f5afa4a0572444a61befe9
 F tclinstaller.tcl 4356d9d94d2b5ed5e68f9f0c80c4df3048dd7617
@@ -619,7 +619,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 17ea0c97a8bac1b34af1f9183d93a2f2a6af9690
-R 14a3c26edfb03c14e19492751537ee30
+P bce289753538ab504e55c4215d6cd4f5df137d9e
+R 151801c4131b431f075bc00e1e6e7959
 U danielk1977
-Z 72270d20c33f439db7efde990ae31655
+Z b54117baecd9504186f4be258a073860

manifest.uuid

@@ -1 +1 @@
-bce289753538ab504e55c4215d6cd4f5df137d9e
+b99d19d651b00dcc7bdb36facfd9ecffe4fafd9f

src/vdbemem.c

@@ -80,7 +80,7 @@ int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve){
     ((pMem->flags&MEM_Static) ? 1 : 0)
   );
 
-  if( sqlite3MallocSize(pMem->zMalloc)<n ){
+  if( !pMem->zMalloc || sqlite3MallocSize(pMem->zMalloc)<n ){
     n = (n>32?n:32);
     if( preserve && pMem->z==pMem->zMalloc ){
       pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);