diff --git a/manifest b/manifest
index 86d2320b48..3495a6f9d0 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Unwind\ssome\scomplex\sconditions\sin\ssqlite3BtreeDelete()\sinto\nseparate\s"if"\sstatements.\s(CVS\s6879)
-D 2009-07-11T13:13:12
+C Bug\sfix\sin\sthe\scomputation\sof\sthe\snumber\sof\spages\sto\sautovacuum\swhen\nnReserve\sis\sgreater\sthan\szero.\s(CVS\s6880)
+D 2009-07-11T17:04:09
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in df9359da7a726ccb67a45db905c5447d5c00c6ef
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -106,7 +106,7 @@ F src/auth.c 802a9439dfa0b8c208b10055cba400e82ef18025
 F src/backup.c 6f1c2d9862c8a3feb7739dfcca02c1f5352e37f3
 F src/bitvec.c 0ef0651714728055d43de7a4cdd95e703fac0119
 F src/btmutex.c 9b899c0d8df3bd68f527b0afe03088321b696d3c
-F src/btree.c a080b574ea4b07df9deca83e0e38e8f08015a0ac
+F src/btree.c 6a5d08b45a7850fde2deec76254ca6a3c1ad7ffc
 F src/btree.h e53a10fd31d16c60a86f03c9467a6f470aa3683b
 F src/btreeInt.h a568bf057aa249eb06fd31358b4393a5ac88c118
 F src/build.c 867028ee9f63f7bc8eb8d4a720bb98cf9b9a12b4
@@ -740,7 +740,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl 672f81d693a03f80f5ae60bfefacd8a349e76746
-P b0853100a9f8e185e8d027502822337a79a2ba0c
-R 05d593da2e562ad999268c4d47bcf9b6
+P d99bde9ca61eeccfe6363ff0882fd4bcdb9a34dc
+R f20bebc61397821a68a2cae56e0278b2
 U drh
-Z f7f774b2e1b61b0e01a61f9c5bfb1c62
+Z 1fcddebe9a4cc8ca7d7de11a8e8fa230
diff --git a/manifest.uuid b/manifest.uuid
index 9b1e1d361b..ae53ff7282 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d99bde9ca61eeccfe6363ff0882fd4bcdb9a34dc
\ No newline at end of file
+618a83d65f973183d21245721dc656a35ff594a4
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index af37d91474..a4d6f4381c 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: btree.c,v 1.678 2009/07/11 13:13:12 drh Exp $
+** $Id: btree.c,v 1.679 2009/07/11 17:04:09 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
@@ -2852,13 +2852,14 @@ static int autoVacuumCommit(BtShared *pBt){
   invalidateAllOverflowCache(pBt);
   assert(pBt->autoVacuum);
   if( !pBt->incrVacuum ){
-    Pgno nFin;
-    Pgno nFree;
-    Pgno nPtrmap;
-    Pgno iFree;
-    const int pgsz = pBt->pageSize;
-    Pgno nOrig = pagerPagecount(pBt);
+    Pgno nFin;         /* Number of pages to be freed */
+    Pgno nFree;        /* Number of pages no the freelist */
+    Pgno nPtrmap;      /* Number of PtrMap pages to be freed */
+    Pgno iFree;        /* The next page to be freed */
+    int nEntry;        /* Number of entries on one ptrmap page */
+    Pgno nOrig;        /* Database size before freeing */
 
+    nOrig = pagerPagecount(pBt);
     if( PTRMAP_ISPAGE(pBt, nOrig) || nOrig==PENDING_BYTE_PAGE(pBt) ){
       /* It is not possible to create a database for which the final page
       ** is either a pointer-map page or the pending-byte page. If one
@@ -2868,7 +2869,8 @@ static int autoVacuumCommit(BtShared *pBt){
     }
 
     nFree = get4byte(&pBt->pPage1->aData[36]);
-    nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+pgsz/5)/(pgsz/5);
+    nEntry = pBt->usableSize/5;
+    nPtrmap = (nFree-nOrig+PTRMAP_PAGENO(pBt, nOrig)+nEntry)/nEntry;
     nFin = nOrig - nFree - nPtrmap;
     if( nOrig>PENDING_BYTE_PAGE(pBt) && nFin<PENDING_BYTE_PAGE(pBt) ){
       nFin--;