Fix an auto-vacuum bug for btree entries that span more than one overflow page. (CVS 2039)

FossilOrigin-Name: 40249ed19cd53cb61f9575d8165316faf2627479

manifest

@@ -1,5 +1,5 @@
-C Require\sthat\sthe\spage\ssize\sbe\sa\spower\sof\s2.\s(CVS\s2038)
-D 2004-11-02T14:24:34
+C Fix\san\sauto-vacuum\sbug\sfor\sbtree\sentries\sthat\sspan\smore\sthan\sone\soverflow\spage.\s(CVS\s2039)
+D 2004-11-02T14:40:32
 F Makefile.in 9e90c685d69f09039015a6b1f3b0a48e9738c9e5
 F Makefile.linux-gcc a9e5a0d309fa7c38e7c14d3ecf7690879d3a5457
 F README a01693e454a00cc117967e3f9fdab2d4d52e9bc1
@@ -29,7 +29,7 @@ F sqlite3.def dbaeb20c153e1d366e8f421b55a573f5dfc00863
 F sqlite3.pc.in 985b9bf34192a549d7d370e0f0b6b34a4f61369a
 F src/attach.c e49d09dad9f5f9fb10b4b0c1be5a70ae4c45e689
 F src/auth.c 3b81f2a42f48a62c2c9c9b0eda31a157c681edea
-F src/btree.c 057e97744f4e9ca02d4815db554fd95fdabd60d5
+F src/btree.c 5958f65a3795e91fd017e4902b6ee7fe98169eb0
 F src/btree.h 94dfec0a1722d33359b23e7e310f2b64ffedf029
 F src/build.c bb896c5f85ab749d17ae5d730235134c12c08033
 F src/date.c 34bdb0082db7ec2a83ef00063f7b44e61ee19dad
@@ -87,7 +87,7 @@ F test/attach.test 6ad560eb3e77751a4faecd77da09deac9e38cc41
 F test/attach2.test f7795123d3051ace1672b6d23973da6435de3745
 F test/attach3.test 6d060986ff004ebb89e1876a331d96c6bb62269e
 F test/auth.test 1cc252d9e7b3bdc1314199cbf3a0d3c5ed026c21
-F test/autovacuum.test 77eec318b1be7764b8dcb3198c035edc30cd319f
+F test/autovacuum.test 9ab4fcfb98ac1537548d61ce1e1718794aac4719
 F test/bigfile.test d3744a8821ce9abb8697f2826a3e3d22b719e89f
 F test/bigrow.test f0aeb7573dcb8caaafea76454be3ade29b7fc747
 F test/bind.test a8682ba41433b93bb36a4213a43f282ca9aec5a9
@@ -252,7 +252,7 @@ F www/tclsqlite.tcl 560ecd6a916b320e59f2917317398f3d59b7cc25
 F www/vdbe.tcl 59288db1ac5c0616296b26dce071c36cb611dfe9
 F www/version3.tcl 092a01f5ef430d2c4acc0ae558d74c4bb89638a0
 F www/whentouse.tcl fdacb0ba2d39831e8a6240d05a490026ad4c4e4c
-P d12481f09cbe51c7ea499bc22afec5de3af14ad4
-R ce7547bdb8b99a29e1e65ec61753f1b6
-U drh
-Z ac7564dbdf799e2f506094e004f86e98
+P c33b34dbe9657b151b9ab00a6b50a255fae623f8
+R 6249b189aa86705bd047e7b6eada805a
+U danielk1977
+Z d61c7336a7d899fa402be79ab44af7cd

manifest.uuid

@@ -1 +1 @@
-c33b34dbe9657b151b9ab00a6b50a255fae623f8
+40249ed19cd53cb61f9575d8165316faf2627479

src/btree.c

@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.197 2004/11/02 14:24:34 drh Exp $
+** $Id: btree.c,v 1.198 2004/11/02 14:40:32 danielk1977 Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -1564,8 +1564,9 @@ set_child_ptrmaps_out:
 static void modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
 
   if( eType==PTRMAP_OVERFLOW2 ){
+    /* The pointer is always the first 4 bytes of the page in this case.  */
     assert( get4byte(pPage->aData)==iFrom );
-    put4byte(pPage->aData, iFrom);
+    put4byte(pPage->aData, iTo);
   }else{
     int isInitOrig = pPage->isInit;
     int i;
@@ -1574,8 +1575,6 @@ static void modifyPagePointer(MemPage *pPage, Pgno iFrom, Pgno iTo, u8 eType){
     initPage(pPage, 0);
     nCell = pPage->nCell;
 
-   /*  assert( !pPage->leaf && eType==PTRMAP_BTREE ); */
-
     for(i=0; i<nCell; i++){
       u8 *pCell = findCell(pPage, i);
       if( eType==PTRMAP_OVERFLOW1 ){
@@ -1695,8 +1694,8 @@ static int autoVacuumCommit(Btree *pBt){
     }while( iFreePage>finDbSize );
 
     /* Move page iDbPage from it's current location to page number iFreePage */
-    TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d)\n", 
-        iDbPage, iFreePage, iPtrPage));
+    TRACE(("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n", 
+        iDbPage, iFreePage, iPtrPage, eType));
     releasePage(pFreeMemPage);
     pFreeMemPage = 0;
     rc = sqlite3pager_movepage(pPager, pDbPage, iFreePage);
@@ -1706,10 +1705,21 @@ static int autoVacuumCommit(Btree *pBt){
     /* If pDbPage was a btree-page, then it may have child pages and/or cells
     ** that point to overflow pages. The pointer map entries for all these
     ** pages need to be changed.
+    **
+    ** If pDbPage is an overflow page, then the first 4 bytes may store a
+    ** pointer to a subsequent overflow page. If this is the case, then
+    ** the pointer map needs to be updated for the subsequent overflow page.
     */
     if( eType==PTRMAP_BTREE ){
       rc = setChildPtrmaps(pDbMemPage);
       if( rc!=SQLITE_OK ) goto autovacuum_out;
+    }else{
+      Pgno nextOvfl = get4byte(pDbPage);
+      if( nextOvfl!=0 ){
+        assert( nextOvfl<=origDbSize );
+        rc = ptrmapPut(pBt, nextOvfl, PTRMAP_OVERFLOW2, iFreePage);
+        if( rc!=SQLITE_OK ) goto autovacuum_out;
+      }
     }
     releasePage(pDbMemPage);
     pDbMemPage = 0;

test/autovacuum.test

@@ -11,7 +11,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this file is testing the SELECT statement.
 #
-# $Id: autovacuum.test,v 1.1 2004/11/02 12:56:41 danielk1977 Exp $
+# $Id: autovacuum.test,v 1.2 2004/11/02 14:40:32 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -28,10 +28,11 @@ proc file_pages {} {
 do_test autovacuum-1.1 {
   execsql {
     CREATE TABLE av1(a);
+    -- CREATE INDEX av1_idx ON av1(a);
   }
 } {}
 
-set ENTRY_LEN 1100
+set ENTRY_LEN 3000
 
 set delete_orders [list]
 lappend delete_orders {1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20}