Index: mptest/config02.test
==================================================================
--- mptest/config02.test
+++ mptest/config02.test
@@ -4,17 +4,17 @@
 PRAGMA page_size=512;
 --task 1
   PRAGMA mmap_limit=0;
 --end
 --task 2
-  PRAGMA mmap_limit=28672;
+  PRAGMA mmap_limit=0;
 --end
 --task 3
-  PRAGMA mmap_limit=8192;
+  PRAGMA mmap_limit=0;
 --end
 --task 4
-  PRAGMA mmap_limit=65536;
+  PRAGMA mmap_limit=0;
 --end
 --source multiwrite01.test
 --source crash02.subtest
 PRAGMA page_size=1024;
 VACUUM;

Index: src/os_unix.c
==================================================================
--- src/os_unix.c
+++ src/os_unix.c
@@ -1876,10 +1876,12 @@
 static int unixClose(sqlite3_file *id){
   int rc = SQLITE_OK;
   unixFile *pFile = (unixFile *)id;
   unixUnlock(id, NO_LOCK);
   unixEnterMutex();
+
+access(pFile->zPath, F_OK);
 
   /* unixFile.pInode is always valid here. Otherwise, a different close
   ** routine (e.g. nolockClose()) would be called instead.
   */
   assert( pFile->pInode->nLock>0 || pFile->pInode->bProcessLock==0 );
@@ -3211,10 +3213,12 @@
   assert( pFile->pUnused==0
        || offset>=PENDING_BYTE+512
        || offset+amt<=PENDING_BYTE 
   );
 #endif
+
+access(pFile->zPath, F_OK);
 
 #ifdef SQLITE_DEBUG
   /* If we are doing a normal write to a database file (as opposed to
   ** doing a hot-journal rollback or a write to some file other than a
   ** normal database file) then record the fact that the database
@@ -5572,10 +5576,11 @@
       assert( !p->pUnused );
       assert( eType==SQLITE_OPEN_WAL || eType==SQLITE_OPEN_MAIN_JOURNAL );
       return rc;
     }
     fd = robust_open(zName, openFlags, openMode);
+    access(zName, F_OK);
     OSTRACE(("OPENX   %-3d %s 0%o\n", fd, zName, openFlags));
     if( fd<0 && errno!=EISDIR && isReadWrite && !isExclusive ){
       /* Failed to open the file for read/write access. Try read-only. */
       flags &= ~(SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE);
       openFlags &= ~(O_RDWR|O_CREAT);
@@ -5707,10 +5712,11 @@
   int dirSync               /* If true, fsync() directory after deleting file */
 ){
   int rc = SQLITE_OK;
   UNUSED_PARAMETER(NotUsed);
   SimulateIOError(return SQLITE_IOERR_DELETE);
+  access(zPath, F_OK);
   if( osUnlink(zPath)==(-1) ){
     if( errno==ENOENT ){
       rc = SQLITE_IOERR_DELETE_NOENT;
     }else{
       rc = unixLogError(SQLITE_IOERR_DELETE, "unlink", zPath);

Index: src/pager.c
==================================================================
--- src/pager.c
+++ src/pager.c
@@ -1964,10 +1964,11 @@
            || pPager->journalMode==PAGER_JOURNALMODE_WAL 
       );
       sqlite3OsClose(pPager->jfd);
       if( bDelete ){
         rc = sqlite3OsDelete(pPager->pVfs, pPager->zJournal, 0);
+assert( rc!=SQLITE_IOERR_DELETE_NOENT );
       }
     }
   }
 
 #ifdef SQLITE_CHECK_PAGES
@@ -2471,10 +2472,11 @@
     zJournal += (sqlite3Strlen30(zJournal)+1);
   }
  
   sqlite3OsClose(pMaster);
   rc = sqlite3OsDelete(pVfs, zMaster, 0);
+assert( rc!=SQLITE_IOERR_DELETE_NOENT );
 
 delmaster_out:
   sqlite3_free(zMasterJournal);
   if( pMaster ){
     sqlite3OsClose(pMaster);

Index: src/vdbeaux.c
==================================================================
--- src/vdbeaux.c
+++ src/vdbeaux.c
@@ -1929,10 +1929,11 @@
     /* Delete the master journal file. This commits the transaction. After
     ** doing this the directory is synced again before any individual
     ** transaction files are deleted.
     */
     rc = sqlite3OsDelete(pVfs, zMaster, 1);
+assert( rc!=SQLITE_IOERR_DELETE_NOENT );
     sqlite3DbFree(db, zMaster);
     zMaster = 0;
     if( rc ){
       return rc;
     }