From 6e465eb0fca6ff5e55c2341978c7db6beb7b62c3 Mon Sep 17 00:00:00 2001
From: danielk1977 <danielk1977@noemail.net>
Date: Tue, 21 Aug 2007 13:11:00 +0000
Subject: [PATCH] Avoid journalling an extra page when a btree insert operation
 uses the 'quick-balance' trick. (CVS 4257)

FossilOrigin-Name: 0da48209140b6c1ba47df799ce6065054b994f02
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/btree.c   | 30 +++++++++++++++++++-----------
 3 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/manifest b/manifest
index 9015d079db..f03b48d0ae 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\ssome\sproblems\sin\sthe\scrash-test\sbackend.\s(CVS\s4256)
-D 2007-08-21T13:07:47
+C Avoid\sjournalling\san\sextra\spage\swhen\sa\sbtree\sinsert\soperation\suses\sthe\s'quick-balance'\strick.\s(CVS\s4257)
+D 2007-08-21T13:11:01
 F Makefile.in 0c0e53720f658c7a551046442dd7afba0b72bfbe
 F Makefile.linux-gcc 65241babba6faf1152bf86574477baab19190499
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -80,7 +80,7 @@ F src/alter.c f0aac0060ae8102e58f210b44d35b53438d53173
 F src/analyze.c a14237d869c6bea0846493b59317e4097e81a0b6
 F src/attach.c a52225c75b107be8c5bc144a2b6d20201be3f8f8
 F src/auth.c 5ea90bc93dfea46e9fe4bf531e14c7cd98219ecb
-F src/btree.c 9460e9ad37b39f4d397b6207f25814e8dd4db6e9
+F src/btree.c 8e529f390d8d1d83acbaf13cb1c09da8361cf5b1
 F src/btree.h 525105564c87111922412368f2e4301c36e74ac1
 F src/btreeInt.h e93edf57832278138b98cf60cbc54241103c6988
 F src/build.c add67be992307b4b11849a6611bfd3352aacde92
@@ -557,7 +557,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P fbbd5bda544ffec4e1b43407b12e546235dc7873
-R 0ca0858c81f7f856c15261fd84ff79c4
+P 5bced2392ad77aff0aa1ddea83f2ff9e3ffe28a8
+R 62bf9d7ba713afd09c97220ab74284f7
 U danielk1977
-Z d922b4212f9baf5077c8cc76317915f9
+Z b65c4a9665c9f568889e6d02dbdc7083
diff --git a/manifest.uuid b/manifest.uuid
index 35465946bf..52d3aa52d4 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-5bced2392ad77aff0aa1ddea83f2ff9e3ffe28a8
\ No newline at end of file
+0da48209140b6c1ba47df799ce6065054b994f02
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index e69806cd57..8f648a9094 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 1.404 2007/08/20 23:50:25 drh Exp $
+** $Id: btree.c,v 1.405 2007/08/21 13:11:01 danielk1977 Exp $
 **
 ** This file implements a external (disk-based) database using BTrees.
 ** See the header comment on "btreeInt.h" for additional information.
@@ -4499,7 +4499,6 @@ static int insertCell(
 
   assert( i>=0 && i<=pPage->nCell+pPage->nOverflow );
   assert( sz==cellSizePtr(pPage, pCell) );
-  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   if( pPage->nOverflow || sz+2>pPage->nFree ){
     if( pTemp ){
@@ -4512,6 +4511,11 @@ static int insertCell(
     pPage->aOvfl[j].idx = i;
     pPage->nFree = 0;
   }else{
+    int rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc!=SQLITE_OK ){
+      return rc;
+    }
+    assert( sqlite3PagerIswriteable(pPage->pDbPage) );
     data = pPage->aData;
     hdr = pPage->hdrOffset;
     top = get2byte(&data[hdr+5]);
@@ -4519,7 +4523,7 @@ static int insertCell(
     end = cellOffset + 2*pPage->nCell + 2;
     ins = cellOffset + 2*i;
     if( end > top - sz ){
-      int rc = defragmentPage(pPage);
+      rc = defragmentPage(pPage);
       if( rc!=SQLITE_OK ) return rc;
       top = get2byte(&data[hdr+5]);
       assert( end + sz <= top );
@@ -4547,7 +4551,7 @@ static int insertCell(
       assert( (info.nData+(pPage->intKey?0:info.nKey))==info.nPayload );
       if( (info.nData+(pPage->intKey?0:info.nKey))>info.nLocal ){
         Pgno pgnoOvfl = get4byte(&pCell[info.iOverflow]);
-        int rc = ptrmapPut(pPage->pBt, pgnoOvfl, PTRMAP_OVERFLOW1, pPage->pgno);
+        rc = ptrmapPut(pPage->pBt, pgnoOvfl, PTRMAP_OVERFLOW1, pPage->pgno);
         if( rc!=SQLITE_OK ) return rc;
       }
     }
@@ -4782,7 +4786,7 @@ static int balance_nonroot(MemPage *pPage){
   ** Find the parent page.
   */
   assert( pPage->isInit );
-  assert( sqlite3PagerIswriteable(pPage->pDbPage) );
+  assert( sqlite3PagerIswriteable(pPage->pDbPage) || pPage->nOverflow==1 );
   pBt = pPage->pBt;
   pParent = pPage->pParent;
   assert( pParent );
@@ -4816,6 +4820,10 @@ static int balance_nonroot(MemPage *pPage){
   }
 #endif
 
+  if( SQLITE_OK!=(rc = sqlite3PagerWrite(pPage->pDbPage)) ){
+    return rc;
+  }
+
   /*
   ** Find the cell in the parent page whose left child points back
   ** to pPage.  The "idx" variable is the index of that cell.  If pPage
@@ -5481,7 +5489,8 @@ static int balance(MemPage *pPage, int insert){
   int rc = SQLITE_OK;
   assert( sqlite3_mutex_held(pPage->pBt->mutex) );
   if( pPage->pParent==0 ){
-    if( pPage->nOverflow>0 ){
+    rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc==SQLITE_OK && pPage->nOverflow>0 ){
       rc = balance_deeper(pPage);
     }
     if( rc==SQLITE_OK && pPage->nCell==0 ){
@@ -5594,11 +5603,6 @@ int sqlite3BtreeInsert(
           pCur->pgnoRoot, nKey, nData, pPage->pgno,
           loc==0 ? "overwrite" : "new entry"));
   assert( pPage->isInit );
-  rc = sqlite3PagerWrite(pPage->pDbPage);
-  if( rc ){
-    sqlite3BtreeLeave(p);
-    return rc;
-  }
   newCell = sqlite3_malloc( MX_CELL_SIZE(pBt) );
   if( newCell==0 ) return SQLITE_NOMEM;
   rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, nZero, &szNew);
@@ -5608,6 +5612,10 @@ int sqlite3BtreeInsert(
   if( loc==0 && CURSOR_VALID==pCur->eState ){
     int szOld;
     assert( pCur->idx>=0 && pCur->idx<pPage->nCell );
+    rc = sqlite3PagerWrite(pPage->pDbPage);
+    if( rc ){
+      goto end_insert;
+    }
     oldCell = findCell(pPage, pCur->idx);
     if( !pPage->leaf ){
       memcpy(newCell, oldCell, 4);