diff --git a/manifest b/manifest
index 86a66d3ecb..70ba7c0179 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Drop\ssupport\sfor\sMAC\sOS9.\s\sSQLite\s3\shas\snever\sworked\sfor\sthat\sOS\sbecause\nthe\sdevelopers\sdo\snot\shave\saccess\sto\sa\smachine\srunning\sit\sand\snobody\sfrom\nthe\scommunity\shas\sstepped\sforward\sto\sprovide\sa\sport.\s\sBy\smoving\sthe\nos_mac.c\sfile\sinto\sthe\sattic,\swe\smake\sthe\slack\sof\ssupport\sofficial.\s(CVS\s2220)
-D 2005-01-16T20:47:41
+C Turn\son\squick-balance\sby\sdefault.\s(CVS\s2221)
+D 2005-01-16T23:21:00
 F Makefile.in 78d6d0af3725aef32468ac9923444d7645d21a28
 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 4a9313065dcfb31c702158ed4c5c0e1ed69889a8
+F src/btree.c 528a661ae10ee7513b3db724a4acfd0e90991798
 F src/btree.h 74d19cf40ab49fd69abe9e4e12a6c321ad86c497
 F src/build.c af1296e8a21a406b4f4c4f1e1365e075071219f3
 F src/cursor.c f883813759742068890b1f699335872bfa8fdf41
@@ -113,7 +113,7 @@ F test/collate4.test 2d6e38e6b871073313f6d4eebfe1435c7173ebfa
 F test/collate5.test 7999fb3122386bae38acd8ccd61e0b7c5a30e289
 F test/collate6.test 6c9470d1606ee3e564675b229653e320c49ec638
 F test/conflict.test c5b849b01cfbe0a4f63a90cba6f68e2fe3a75f87
-F test/corrupt.test 0080ddcece23e8ba47c44608c4fb73fd4d1d8ce2
+F test/corrupt.test 4b289dfd45b5987a4f12bef9693c49e42b6e76ea
 F test/corrupt2.test cb1f813df7559de3021e01170af0bba31507a9a5
 F test/crash.test fa5d79ece85e8f6677bd81703db5f869a15963aa
 F test/crashtest1.c 09c1c7d728ccf4feb9e481671e29dda5669bbcc2
@@ -267,7 +267,7 @@ F www/tclsqlite.tcl e73f8f8e5f20e8277619433f7970060ab01088fc
 F www/vdbe.tcl 095f106d93875c94b47367384ebc870517431618
 F www/version3.tcl 092a01f5ef430d2c4acc0ae558d74c4bb89638a0
 F www/whentouse.tcl c3b50d3ac31c54be2a1af9b488a89d22f1e6e746
-P 6237c294d1211d5848bafb1310574e2486a43757
-R ca099b3c791f0b796eb74e72a082b2c7
+P de9ad673d037f7bfca3a2d439259a63c9ed954db
+R a3c633ca18ad9c504d2c45368f1d4e12
 U drh
-Z 5cc4e0ef8392da0ae950aaff44fc3d28
+Z 9410eca575f29e730c32c01825919813
diff --git a/manifest.uuid b/manifest.uuid
index 3bca49a232..57ca7c6586 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-de9ad673d037f7bfca3a2d439259a63c9ed954db
\ No newline at end of file
+d0356dee55bd43f361ede1344e90d1ba6b5cde1e
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 2b68165de6..167197f3ee 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 1.237 2005/01/16 11:07:07 danielk1977 Exp $
+** $Id: btree.c,v 1.238 2005/01/16 23:21:00 drh Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** For a detailed discussion of BTrees, refer to
@@ -358,12 +358,24 @@ struct BtCursor {
   u8 isValid;               /* TRUE if points to a valid entry */
 };
 
+/*
+** The TRACE macro will print high-level status information about the
+** btree operation when the global variable sqlite3_btree_trace is
+** enabled.
+*/
+#if SQLITE_TEST
+# define TRACE(X)   if( sqlite3_btree_trace )\
+                        { sqlite3DebugPrintf X; fflush(stdout); }
+#else
+# define TRACE(X)
+#endif
+int sqlite3_btree_trace=0;  /* True to enable tracing */
+
 /*
 ** Forward declaration
 */
 static int checkReadLocks(Btree*,Pgno,BtCursor*);
 
-
 /*
 ** Read or write a two- and four-byte big-endian integer values.
 */
@@ -420,12 +432,18 @@ static void put4byte(unsigned char *p, u32 v){
 #define PTRMAP_ISPAGE(pgsz, pgno) (PTRMAP_PAGENO(pgsz,pgno)==pgno)
 
 /*
-** The pointer map is a lookup table that contains an entry for each database
-** page in the file except for page 1. In this context 'database page' refers
-** to any page that is not part of the pointer map itself.  Each pointer map
-** entry consists of a single byte 'type' and a 4 byte page number. The
-** PTRMAP_XXX identifiers below are the valid types. The interpretation
-** of the page-number depends on the type, as follows:
+** The pointer map is a lookup table that identifies the parent page for
+** each child page in the database file.  The parent page is the page that
+** contains a pointer to the child.  Every page in the database contains
+** 0 or 1 parent pages.  (In this context 'database page' refers
+** to any page that is not part of the pointer map itself.)  Each pointer map
+** entry consists of a single byte 'type' and a 4 byte parent page number.
+** The PTRMAP_XXX identifiers below are the valid types.
+**
+** The purpose of the pointer map is to facility moving pages from one
+** position in the file to another as part of autovacuum.  When a page
+** is moved, the pointer in its parent must be updated to point to the
+** new location.  The pointer map is used to locate the parent page quickly.
 **
 ** PTRMAP_ROOTPAGE: The database page is a root-page. The page-number is not
 **                  used in this case.
@@ -457,7 +475,7 @@ static void put4byte(unsigned char *p, u32 v){
 ** so that it maps to type 'eType' and parent page number 'pgno'.
 ** An error code is returned if something goes wrong, otherwise SQLITE_OK.
 */
-static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
+static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno parent){
   u8 *pPtrmap;    /* The pointer map page */
   Pgno iPtrmap;   /* The pointer map page number */
   int offset;     /* Offset in pointer map page */
@@ -472,13 +490,14 @@ static int ptrmapPut(Btree *pBt, Pgno key, u8 eType, Pgno pgno){
   }
   offset = PTRMAP_PTROFFSET(pBt->usableSize, key);
 
-  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=pgno ){
+  if( eType!=pPtrmap[offset] || get4byte(&pPtrmap[offset+1])!=parent ){
+    TRACE(("PTRMAP_UPDATE: %d->(%d,%d)\n", key, eType, parent));
     rc = sqlite3pager_write(pPtrmap);
     if( rc!=0 ){
       return rc;
     }
     pPtrmap[offset] = eType;
-    put4byte(&pPtrmap[offset+1], pgno);
+    put4byte(&pPtrmap[offset+1], parent);
   }
 
   sqlite3pager_unref(pPtrmap);
@@ -1563,19 +1582,6 @@ int sqlite3BtreeBeginTrans(Btree *pBt, int wrflag){
   return rc;
 }
 
-/*
-** The TRACE macro will print high-level status information about the
-** btree operation when the global variable sqlite3_btree_trace is
-** enabled.
-*/
-#if SQLITE_TEST
-# define TRACE(X)   if( sqlite3_btree_trace )\
-                        { sqlite3DebugPrintf X; fflush(stdout); }
-#else
-# define TRACE(X)
-#endif
-int sqlite3_btree_trace=0;  /* True to enable tracing */
-
 #ifndef SQLITE_OMIT_AUTOVACUUM
 
 /*
@@ -3571,6 +3577,7 @@ static void assemblePage(
 /* Forward reference */
 static int balance(MemPage*, int);
 
+#ifndef SQLITE_OMIT_QUICKBALANCE
 /*
 ** This version of balance() handles the common special case where
 ** a new entry is being inserted on the extreme right-end of the
@@ -3658,6 +3665,7 @@ static int balance_quick(MemPage *pPage, MemPage *pParent){
   releasePage(pNew);
   return balance(pParent, 0);
 }
+#endif /* SQLITE_OMIT_QUICKBALANCE */
 
 /*
 ** The ISAUTOVACUUM macro is used within balance_nonroot() to determine
@@ -3747,7 +3755,7 @@ static int balance_nonroot(MemPage *pPage){
   assert( pParent );
   TRACE(("BALANCE: begin page %d child of %d\n", pPage->pgno, pParent->pgno));
 
-#ifdef SQLITE_BALANCE_QUICK
+#ifndef SQLITE_OMIT_QUICKBALANCE
   /*
   ** A special case:  If a new entry has just been inserted into a
   ** table (that is, a btree with integer keys and all data at the leaves)
diff --git a/test/corrupt.test b/test/corrupt.test
index b3aae8d0a6..9874a50e13 100644
--- a/test/corrupt.test
+++ b/test/corrupt.test
@@ -13,7 +13,7 @@
 # This file implements tests to make sure SQLite does not crash or
 # segfault if it sees a corrupt database file.
 #
-# $Id: corrupt.test,v 1.1 2004/08/30 16:52:19 drh Exp $
+# $Id: corrupt.test,v 1.2 2005/01/16 23:21:00 drh Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
@@ -44,7 +44,7 @@ do_test corrupt-1.1 {
   }
 } {ok}
 
-# Copy a file 
+# Copy file $from into $to
 #
 proc copy_file {from to} {
   set f [open $from]
@@ -56,14 +56,19 @@ proc copy_file {from to} {
   close $f
 }
 
-# Setup for the tests.
+# Setup for the tests.  Make a backup copy of the good database in test.bu.
+# Create a string of garbage data that is 256 bytes long.
+#
 copy_file test.db test.bu
 set fsize [file size test.db]
 set junk "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 while {[string length $junk]<256} {append junk $junk}
 set junk [string range $junk 0 255]
 
-
+# Go through the database and write garbage data into each 256 segment
+# of the file.  Then do various operations on the file to make sure that
+# the database engine can recover gracefully from the corruption.
+#
 for {set i [expr {1*256}]} {$i<$fsize-256} {incr i 256} {
   set tn [expr {$i/256}]
   db close
@@ -99,7 +104,6 @@ for {set i [expr {1*256}]} {$i<$fsize-256} {incr i 256} {
     catchsql {DROP TABLE t1}
     set x {}
   } {}
-if {$tn==724} btree_breakpoint
   do_test corrupt-2.$tn.7 {
     catchsql {PRAGMA integrity_check}
     set x {}