Index: src/pager.c
==================================================================
--- src/pager.c
+++ src/pager.c
@@ -356,10 +356,11 @@
   u8 changeCountDone;         /* Set after incrementing the change-counter */
   u32 vfsFlags;               /* Flags for sqlite3_vfs.xOpen() */
   int errCode;                /* One of several kinds of errors */
   int dbSize;                 /* Number of pages in the file */
   int origDbSize;             /* dbSize before the current change */
+  int hintDbSize;             /* dbSize sent to SQLITE_FCNTL_SIZE_HINT */
   int stmtSize;               /* Size of database (in pages) at stmt_begin() */
   int nRec;                   /* Number of pages written to the journal */
   u32 cksumInit;              /* Quasi-random value added to every checksum */
   int stmtNRec;               /* Number of records in stmt subjournal */
   int nExtra;                 /* Add this many bytes to each in-memory page */
@@ -1356,10 +1357,11 @@
         pPager->stmtInUse = 0;
         pPager->journalOff = 0;
         pPager->journalStarted = 0;
         pPager->stmtAutoopen = 0;
         pPager->origDbSize = 0;
+        pPager->hintDbSize = 0;
       }
     }
 
     if( !MEMDB || pPager->errCode==SQLITE_OK ){
       pPager->state = PAGER_UNLOCK;
@@ -1455,10 +1457,11 @@
     pPager->state = PAGER_SHARED;
   }else if( pPager->state==PAGER_SYNCED ){
     pPager->state = PAGER_EXCLUSIVE;
   }
   pPager->origDbSize = 0;
+  pPager->hintDbSize = 0;
   pPager->setMaster = 0;
   pPager->needSync = 0;
   lruListSetFirstSynced(pPager);
   pPager->dbSize = -1;
   pPager->dbModified = 0;
@@ -3030,10 +3033,12 @@
 */
 static int pager_write_pagelist(PgHdr *pList){
   Pager *pPager;
   PgHdr *p;
   int rc;
+  Pgno mxPgno;           /* Maximum page number to be written */
+  int nExtend = 0;       /* Number of pages on pList that extend the file */
 
   if( pList==0 ) return SQLITE_OK;
   pPager = pList->pPager;
 
   /* At this point there may be either a RESERVED or EXCLUSIVE lock on the
@@ -3059,10 +3064,12 @@
 
   pList = sort_pagelist(pList);
   for(p=pList; p; p=p->pDirty){
     assert( p->dirty );
     p->dirty = 0;
+    mxPgno = p->pgno;
+    if( p->pgno>pPager->hintDbSize ) nExtend++;
   }
 
   /* If the file has not yet been opened, open it now. */
   if( !pPager->fd->pMethods ){
     assert(pPager->tempFile);
@@ -3071,13 +3078,17 @@
   }
 
   /* Before the first write, give the VFS a hint of what the final
   ** file size will be.
   */
-  if( pPager->dbSize > (pPager->origDbSize+1) ){
-    sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
+  if( nExtend>1 || (nExtend==1 && pPager->dbSize>mxPgno) ){
+    sqlite3_int64 szFile;
+    assert( pPager->hintDbSize<mxPgno );
+    assert( mxPgno<=pPager->dbSize );
+    szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
     sqlite3OsFileControl(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
+    pPager->hintDbSize = pPager->dbSize;
   }
 
   while( pList ){
     /* If there are dirty pages in the page cache with page numbers greater
     ** than Pager.dbSize, this means sqlite3PagerTruncate() was called to
@@ -4023,11 +4034,11 @@
   pPager->nRec = 0;
   if( pPager->errCode ){
     rc = pPager->errCode;
     goto failed_to_open_journal;
   }
-  pPager->origDbSize = pPager->dbSize;
+  pPager->hintDbSize = pPager->origDbSize = pPager->dbSize;
 
   rc = writeJournalHdr(pPager);
 
   if( pPager->stmtAutoopen && rc==SQLITE_OK ){
     rc = sqlite3PagerStmtBegin(pPager);
@@ -4081,11 +4092,11 @@
   assert( pPager->state!=PAGER_UNLOCK );
   if( pPager->state==PAGER_SHARED ){
     assert( pPager->pInJournal==0 );
     if( MEMDB ){
       pPager->state = PAGER_EXCLUSIVE;
-      pPager->origDbSize = pPager->dbSize;
+      pPager->hintDbSize = pPager->origDbSize = pPager->dbSize;
     }else{
       rc = sqlite3OsLock(pPager->fd, RESERVED_LOCK);
       if( rc==SQLITE_OK ){
         pPager->state = PAGER_RESERVED;
         if( exFlag ){
@@ -4110,19 +4121,20 @@
     ** kept open and either was truncated to 0 bytes or its header was
     ** overwritten with zeros.
     */
     assert( pPager->nRec==0 );
     assert( pPager->origDbSize==0 );
+    assert( pPager->hintDbSize==0 );
     assert( pPager->pInJournal==0 );
     sqlite3PagerPagecount(pPager, 0);
     pagerLeave(pPager);
     pPager->pInJournal = sqlite3BitvecCreate( pPager->dbSize );
     pagerEnter(pPager);
     if( !pPager->pInJournal ){
       rc = SQLITE_NOMEM;
     }else{
-      pPager->origDbSize = pPager->dbSize;
+      pPager->hintDbSize = pPager->origDbSize = pPager->dbSize;
       rc = writeJournalHdr(pPager);
     }
   }
   assert( !pPager->journalOpen || pPager->journalOff>0 || rc!=SQLITE_OK );
   pagerLeave(pPager);
@@ -4913,11 +4925,11 @@
         pPager->xReiniter(p, pPager->pageSize);
       }
     }
     pPager->pDirty = 0;
     pPager->pStmt = 0;
-    pPager->dbSize = pPager->origDbSize;
+    pPager->dbSize = pPager->hintDbSize = pPager->origDbSize;
     pager_truncate_cache(pPager);
     pPager->stmtInUse = 0;
     pPager->state = PAGER_SHARED;
     return SQLITE_OK;
   }

Index: test/io.test
==================================================================
--- test/io.test
+++ test/io.test
@@ -399,11 +399,11 @@
       INSERT INTO abc SELECT * FROM abc;
     }
     # File has grown - showing there was a cache-spill - but there 
     # have been no calls to fsync():
     list [file size test.db] [nSync]
-  } {38912 0}
+  } {36864 0}
   do_test io-3.3 {
     # The COMMIT requires a single fsync() - to the database file.
     execsql { COMMIT }
     list [file size test.db] [nSync]
   } {39936 1}