Fix a database corruption problem that can occur in auto-vacuum mode when

a malloc() failure causes a statement rollback, additional statements
are run in the same transaction, then the total transaction rolls back. (CVS 4079)

FossilOrigin-Name: c9dcf2b926c99ff9cee68589f364461ab2a1d11f

manifest

@@ -1,5 +1,5 @@
-C Additional\sdebugging\sinstrumentation\sadded\sto\sthe\spager.\s(CVS\s4078)
+C Fix\sa\sdatabase\scorruption\sproblem\sthat\scan\soccur\sin\sauto-vacuum\smode\swhen\na\smalloc()\sfailure\scauses\sa\sstatement\srollback,\sadditional\sstatements\nare\srun\sin\sthe\ssame\stransaction,\sthen\sthe\stotal\stransaction\srolls\sback.\s(CVS\s4079)
-D 2007-06-16T03:06:28
+D 2007-06-16T04:42:12
 F Makefile.in b9971ab07868cf2b3209fe3bf8c52e7e25af4193
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -94,7 +94,7 @@ F src/os_unix.c f2ccf2e9a925fc679faf7a8fe85700e0f13cf0e1
 F src/os_unix.h 5768d56d28240d3fe4537fac08cc85e4fb52279e
 F src/os_win.c d868d5f9e95ec9c1b9e2a30c54c996053db6dddd
 F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
-F src/pager.c a4a02246d23edcc8113f5957d7db4772d9cd71bc
+F src/pager.c a8e5c2fd00737ddd7d8c8416d0fdbbf904d78b64
 F src/pager.h 94110a5570dca30d54a883e880a3633b2e4c05ae
 F src/parse.y 2ed1d91fdcb4ae7ae7d1f4674544297807c7cc26
 F src/pragma.c 0d25dad58bdfd6789943a10f1b9663c2eb85b96d
@@ -506,7 +506,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P 7d3c1f08a34fcf2ca5c79d6e58f713ae6a4b34e8
+P dcdb20f81ae923f6f56d75c7b8b89a0b3abff954
-R 22dcb4d1b3c757bf921381ac2ad50631
+R e52cc159103410bf628cb2caa9ba87b2
 U drh
-Z aa8c8e6b272cf52bad3cb3c217bce91b
+Z 5e8ccb501c2183f5e479995480e6033d

manifest.uuid

@@ -1 +1 @@
-dcdb20f81ae923f6f56d75c7b8b89a0b3abff954
+c9dcf2b926c99ff9cee68589f364461ab2a1d11f

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.344 2007/06/16 03:06:28 drh Exp $
+** @(#) $Id: pager.c,v 1.345 2007/06/16 04:42:12 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -1106,13 +1106,14 @@ static int pager_playback_one_page(Pager *pPager, OsFile *jfd, int useCksum){
   ** This occurs when a page is changed prior to the start of a statement
   ** then changed again within the statement.  When rolling back such a
   ** statement we must not write to the original database unless we know
-  ** for certain that original page contents are in the main rollback
+  ** for certain that original page contents are synced into the main rollback
-  ** journal.  Otherwise, if a full ROLLBACK occurs after the statement
+  ** journal.  Otherwise, a power loss might leave modified data in the
-  ** rollback the full ROLLBACK will not restore the page to its original
+  ** database file without an entry in the rollback journal that can
-  ** content.  Two conditions must be met before writing to the database
+  ** restore the database to its original form.  Two conditions must be
-  ** files. (1) the database must be locked.  (2) we know that the original
+  ** met before writing to the database files. (1) the database must be
-  ** page content is in the main journal either because the page is not in
+  ** locked.  (2) we know that the original page content is fully synced
-  ** cache or else it is marked as needSync==0.
+  ** in the main journal either because the page is not in cache or else
+  ** the page is marked as needSync==0.
   */
   pPg = pager_lookup(pPager, pgno);
   PAGERTRACE4("PLAYBACK %d page %d hash(%08x)\n",
@@ -4243,15 +4244,15 @@ void sqlite3PagerSetCodec(
 
 #ifndef SQLITE_OMIT_AUTOVACUUM
 /*
-** Move the page identified by pData to location pgno in the file. 
+** Move the page pPg to location pgno in the file. 
 **
-** There must be no references to the current page pgno. If current page
+** There must be no references to the page previously located at
-** pgno is not already in the rollback journal, it is not written there by
+** pgno (which we call pPgOld) though that page is allowed to be
-** by this routine. The same applies to the page pData refers to on entry to
+** in cache.  If the page previous located at pgno is not already
-** this routine.
+** in the rollback journal, it is not put there by by this routine.
 **
-** References to the page refered to by pData remain valid. Updating any
+** References to the page pPg remain valid. Updating any
-** meta-data associated with page pData (i.e. data stored in the nExtra bytes
+** meta-data associated with pPg (i.e. data stored in the nExtra bytes
 ** allocated along with the page) is the responsibility of the caller.
 **
 ** A transaction must be active when this routine is called. It used to be
@@ -4260,7 +4261,7 @@ void sqlite3PagerSetCodec(
 ** transaction is active).
 */
 int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno){
-  PgHdr *pPgOld; 
+  PgHdr *pPgOld;  /* The page being overwritten. */
   int h;
   Pgno needSyncPgno = 0;
 
@@ -4286,17 +4287,23 @@ int sqlite3PagerMovepage(Pager *pPager, DbPage *pPg, Pgno pgno){
   ** page pgno before the 'move' operation, it needs to be retained 
   ** for the page moved there.
   */
+  pPg->needSync = 0;
   pPgOld = pager_lookup(pPager, pgno);
   if( pPgOld ){
     assert( pPgOld->nRef==0 );
     unlinkHashChain(pPager, pPgOld);
     makeClean(pPgOld);
-    if( pPgOld->needSync ){
+    pPg->needSync = pPgOld->needSync;
-      assert( pPgOld->inJournal );
+  }else{
-      pPg->inJournal = 1;
+    pPg->needSync = 0;
-      pPg->needSync = 1;
+  }
-      assert( pPager->needSync );
+  if( pPager->aInJournal && (int)pgno<=pPager->origDbSize ){
-    }
+    pPg->inJournal =  (pPager->aInJournal[pgno/8] & (1<<(pgno&7)))!=0;
+  }else if( (int)pgno>=pPager->origDbSize ){
+    pPg->inJournal = 1;
+  }else{
+    pPg->inJournal = 0;
+    assert( pPg->needSync==0 );
   }
 
   /* Change the page number for pPg and insert it into the new hash-chain. */