Fix to sqlite3DbMallocRaw() when SQLITE_OMIT_LOOKASIDE is defined so that

once it fails it continues to fail.  Add a comment explaining why this is
important. (CVS 5804)

FossilOrigin-Name: 63dd8be70d333c56171dfd254406abb1af685b0f

manifest

@@ -1,5 +1,5 @@
-C Fix\sa\sOOM\ssegfault\sin\sthe\sBETWEEN\soperator\sparsing\s-\sdiscovered\swhile\nusing\sSQLITE_OMIT_LOOKASIDE.\sAdd\sSQLITE_OMIT_LOOKASIDE\sto\stest_config.c\sand\nbypass\slookaside.test\swhen\sdefined.\s(CVS\s5803)
-D 2008-10-11T17:06:04
+C Fix\sto\ssqlite3DbMallocRaw()\swhen\sSQLITE_OMIT_LOOKASIDE\sis\sdefined\sso\sthat\nonce\sit\sfails\sit\scontinues\sto\sfail.\s\sAdd\sa\scomment\sexplaining\swhy\sthis\sis\nimportant.\s(CVS\s5804)
+D 2008-10-11T17:35:16
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 7fc26e087207e7a4a7723583dbd7997477af3b13
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -119,7 +119,7 @@ F src/journal.c cffd2cd214e58c0e99c3ff632b3bee6c7cbb260e
 F src/legacy.c aac57bd984e666059011ea01ec4383892a253be3
 F src/loadext.c cadd5df14bcda5ef0c26d815eb609a755861923e
 F src/main.c 479e3b64066ac58d9957795608b0950425877f5f
-F src/malloc.c 20613ebf4664dec6eb47f62d76264b24ee2a7e4a
+F src/malloc.c 08f39c0fbc85f363d153452fc926cbcaebbef951
 F src/mem1.c 5a529ff121c55ab067be14de00f86f6dcc4f4fb9
 F src/mem2.c f87e681d0d1ed8436870d089332ed0d27d885b5c
 F src/mem3.c 1594f117fde4cf11a6c16521f3f30af8d04bbe68
@@ -140,7 +140,7 @@ F src/os_unix.c f33b69d8a85372b270fe37ee664a4c2140a5217d
 F src/os_win.c 04033a86a39f49cb8e348f515eb0116aa9d36678
 F src/pager.c d98f56128e849083f2f612196efebd982c491fea
 F src/pager.h 9c1917be28fff58118e1fe0ddbc7adfb8dd4f44d
-F src/parse.y e73dc4137eaf060c5836e04f7caf6ad54158dc8a
+F src/parse.y f4620f42b5e0141e20243b5f963d0fc9c180ab9b
 F src/pcache.c f8d7beceba164a34441ac37e88abb3a404f968a7
 F src/pcache.h 28d9ce2d66909db1f01652586450b62b64793093
 F src/pragma.c f0f48d0d50e9d8fa785178fc2410244c06f6a287
@@ -648,7 +648,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 56fb7a22864774fcbd8cd00195359dc0f223ec8b
-R 2158ce4512a57fd4db4ca2df18c87ec3
+P 2a21d52c651ba113c472b6686dcf8ba009924305
+R 53242d9d091be371ffc0e60642760de2
 U drh
-Z 074e8ac5d86169b627d2bfca4057a8c5
+Z 6ab1452927e4563cdd9448fe0603ea26

manifest.uuid

@@ -1 +1 @@
-2a21d52c651ba113c472b6686dcf8ba009924305
+63dd8be70d333c56171dfd254406abb1af685b0f

src/malloc.c

@@ -12,7 +12,7 @@
 **
 ** Memory allocation functions used throughout sqlite.
 **
-** $Id: malloc.c,v 1.43 2008/10/11 15:38:30 drh Exp $
+** $Id: malloc.c,v 1.44 2008/10/11 17:35:16 drh Exp $
 */
 #include "sqliteInt.h"
 #include <stdarg.h>
@@ -618,6 +618,20 @@ void *sqlite3DbMallocZero(sqlite3 *db, int n){
 /*
 ** Allocate and zero memory.  If the allocation fails, make
 ** the mallocFailed flag in the connection pointer.
+**
+** If db!=0 and db->mallocFailed is true (indicating a prior malloc
+** failure on the same database connection) then always return 0.
+** Hence for a particular database connection, once malloc starts
+** failing, it fails consistently until mallocFailed is reset.
+** This is an important assumption.  There are many places in the
+** code that do things like this:
+**
+**         int *a = (int*)sqlite3DbMallocRaw(db, 100);
+**         int *b = (int*)sqlite3DbMallocRaw(db, 200);
+**         if( b ) a[10] = 9;
+**
+** In other words, if a subsequent malloc (ex: "b") worked, it is assumed
+** that all prior mallocs (ex: "a") worked too.
 */
 void *sqlite3DbMallocRaw(sqlite3 *db, int n){
   void *p;
@@ -637,6 +651,10 @@ void *sqlite3DbMallocRaw(sqlite3 *db, int n){
       return (void*)pBuf;
     }
   }
+#else
+  if( db && db->mallocFailed ){
+    return 0;
+  }
 #endif
   p = sqlite3Malloc(n);
   if( !p && db ){

src/parse.y

@@ -14,7 +14,7 @@
 ** the parser.  Lemon will also generate a header file containing
 ** numeric codes for all of the tokens.
 **
-** @(#) $Id: parse.y,v 1.260 2008/10/11 17:06:04 drh Exp $
+** @(#) $Id: parse.y,v 1.261 2008/10/11 17:35:16 drh Exp $
 */
 
 // All token codes are small integers with #defines that begin with "TK_"
@@ -803,9 +803,7 @@ expr(A) ::= expr(W) between_op(N) expr(X) AND expr(Y). [BETWEEN] {
     sqlite3ExprListDelete(pParse->db, pList);
   } 
   if( N ) A = sqlite3PExpr(pParse, TK_NOT, A, 0, 0);
-  if( !pParse->db->mallocFailed ){
-    sqlite3ExprSpan(A,&W->span,&Y->span);
-  }
+  sqlite3ExprSpan(A,&W->span,&Y->span);
 }
 %ifndef SQLITE_OMIT_SUBQUERY
   %type in_op {int}