1 files changed, 18 insertions, 3 deletions

diff --git a/src/backup.c b/src/backup.c
index d3614b88c..71a8a1a3e 100644
--- a/src/backup.c
+++ b/src/backup.c
@@ -462,7 +462,6 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           nDestTruncate = nSrcPage * (pgszSrc/pgszDest);
         }
         assert( nDestTruncate>0 );
-        sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
 
         if( pgszSrc<pgszDest ){
           /* If the source page-size is smaller than the destination page-size,
@@ -476,6 +475,8 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
           */
           const i64 iSize = (i64)pgszSrc * (i64)nSrcPage;
           sqlite3_file * const pFile = sqlite3PagerFile(pDestPager);
+          Pgno iPg;
+          int nDstPage;
           i64 iOff;
           i64 iEnd;
 
@@ -486,13 +487,26 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
              && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest
           ));
 
-          /* This call ensures that all data required to recreate the original
+          /* This block ensures that all data required to recreate the original
           ** database has been stored in the journal for pDestPager and the
           ** journal synced to disk. So at this point we may safely modify
           ** the database file in any way, knowing that if a power failure
           ** occurs, the original database will be reconstructed from the 
           ** journal file.  */
-          rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
+          sqlite3PagerPagecount(pDestPager, &nDstPage);
+          for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){
+            if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){
+              DbPage *pPg;
+              rc = sqlite3PagerGet(pDestPager, iPg, &pPg);
+              if( rc==SQLITE_OK ){
+                rc = sqlite3PagerWrite(pPg);
+                sqlite3PagerUnref(pPg);
+              }
+            }
+          }
+          if( rc==SQLITE_OK ){
+            rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1);
+          }
 
           /* Write the extra pages and truncate the database file as required */
           iEnd = MIN(PENDING_BYTE + pgszDest, iSize);
@@ -519,6 +533,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
             rc = sqlite3PagerSync(pDestPager);
           }
         }else{
+          sqlite3PagerTruncateImage(pDestPager, nDestTruncate);
           rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0);
         }