Fix an obscure problem with recovery from I/O errors while rolling back. (CVS 6498)

FossilOrigin-Name: 24ff486125b9ad62dd92314b62299093b55fe82b

manifest

@@ -1,5 +1,5 @@
-C Add\sa\scomments\sand\san\sassert()\sto\sthe\svirtual\stable\simplementation.\nNo\sfunctional\schanges.\s(CVS\s6497)
-D 2009-04-11T16:27:20
+C Fix\san\sobscure\sproblem\swith\srecovery\sfrom\sI/O\serrors\swhile\srolling\sback.\s(CVS\s6498)
+D 2009-04-11T16:27:50
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 583e87706abc3026960ed759aff6371faf84c211
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -143,7 +143,7 @@ F src/os_common.h 8c61457df58f1a4bd5f5adc3e90e01b37bf7afbc
 F src/os_os2.c bed77dc26e3a95ce4a204936b9a1ca6fe612fcc5
 F src/os_unix.c 9ad9f45049a3c9eb0b0713b162ff0d7024ff7259
 F src/os_win.c 25092e59f1e5969779c393fd75bc945c2f375513
-F src/pager.c 9775c0db675e4d9f2f0e51a04c3ec90df84c4519
+F src/pager.c e8d2bb957f01f1d030798b8ee039327bb3000d65
 F src/pager.h 0c9f3520c00d8a3b8e792ca56c9a11b6b02b4b0f
 F src/parse.y b7e4341b21736a90b952aa6bb663ec98529b778e
 F src/pcache.c 395f752a13574120bd7513a400ba02a265aaa76d
@@ -450,7 +450,7 @@ F test/malloc9.test 2307c6ee3703b0a21391f3ea92388b4b73f9105e
 F test/mallocA.test 4b650c745aab289079454f4d1c02abe5c97ab6b3
 F test/mallocAll.test 2a2222a5e447be6c6579055a9a26e507e4586f4e
 F test/mallocB.test bc475ab850cda896142ab935bbfbc74c24e51ed6
-F test/mallocC.test 05c0bde2e41cdbdef26b9c17b8e48c935b46f611
+F test/mallocC.test 7fcfb7c6cab30dc90d0fe3f2d5e3bcda5de33761
 F test/mallocD.test f78c295e8e18ea3029e65ca08278690e00c22100
 F test/mallocE.test db1ed69d7eded1b080952e2a7c37f364ad241b08
 F test/mallocF.test 2d5c590ebc2fc7f0dcebdf5aa8498b9aed69107e
@@ -717,7 +717,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 2c560e057e1da8a603efc36deea036f2392a4ab9
-R c933794e7ad3da191304723b50287bf2
+P ac5d0c0aa1de687bde972fbf0db8f04508825205
+R db20b0e5c24f9161459a802e68304a17
 U drh
-Z 1604cbd2809b3455fe72d9ed10306c85
+Z afe80c413e7ff05c545dbc4f3e72caef

manifest.uuid

@@ -1 +1 @@
-ac5d0c0aa1de687bde972fbf0db8f04508825205
+24ff486125b9ad62dd92314b62299093b55fe82b

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.579 2009/04/11 09:51:56 danielk1977 Exp $
+** @(#) $Id: pager.c,v 1.580 2009/04/11 16:27:50 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -2024,11 +2024,11 @@ static int pager_playback(Pager *pPager, int isHot){
           pPager->journalOff = szJ;
           break;
         }else{
-          /* If we are unable to rollback, then the database is probably
-          ** going to end up being corrupt.  It is corrupt to us, anyhow.
-          ** Perhaps the next process to come along can fix it....
+          /* If we are unable to rollback, quit and return the error
+          ** code.  This will cause the pager to enter the error state
+          ** so that no further harm will be done.  Perhaps the next
+          ** process to come along will be able to rollback the database.
           */
-          rc = SQLITE_CORRUPT_BKPT;
           goto end_playback;
         }
       }

test/mallocC.test

@@ -12,7 +12,7 @@
 # This file tests aspects of the malloc failure while parsing
 # CREATE TABLE statements in auto_vacuum mode.
 #
-# $Id: mallocC.test,v 1.9 2008/02/18 22:24:58 drh Exp $
+# $Id: mallocC.test,v 1.10 2009/04/11 16:27:50 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -87,6 +87,22 @@ execsql {
   PRAGMA auto_vacuum=1;
   CREATE TABLE t0(a, b, c);
 }
+
+# The number of memory allocation failures is different on 64-bit
+# and 32-bit systems due to larger structures on 64-bit systems
+# overflowing the lookaside more often.  To debug problems, it is
+# sometimes helpful to reduce the size of the lookaside allocation
+# blocks.  But this is normally disabled.
+#
+if {0} {
+  db close
+  sqlite3_shutdown
+  sqlite3_config_lookaside 50 500
+  sqlite3_initialize
+  autoinstall_test_functions
+  sqlite3 db test.db
+}
+
 do_mallocC_test 1 -sql {
   BEGIN;
   -- Allocate 32 new root pages. This will exercise the 'extract specific