File sqlite3-xFetch-null.patch of Package sqlite3.13258

--- sqlite3.c	2015-05-20 20:28:12.000000000 +0200
+++ sqlite3.c	2017-03-02 21:14:13.050598000 +0100
@@ -78510,7 +78510,9 @@
 */
 static int vdbeSorterMapFile(SortSubtask *pTask, SorterFile *pFile, u8 **pp){
   int rc = SQLITE_OK;
-  if( pFile->iEof<=(i64)(pTask->pSorter->db->nMaxSorterMmap) ){
+  if( pFile->iEof<=(i64)(pTask->pSorter->db->nMaxSorterMmap) 
+   && pFile->pFd->pMethods->xFetch
+  ){
     sqlite3_file *pFd = pFile->pFd;
     if( pFd->pMethods->iVersion>=3 ){
       rc = sqlite3OsFetch(pFd, 0, (int)pFile->iEof, (void**)pp);
@@ -79167,7 +79169,9 @@
 ** the specific VFS implementation.
 */
 static void vdbeSorterExtendFile(sqlite3 *db, sqlite3_file *pFd, i64 nByte){
-  if( nByte<=(i64)(db->nMaxSorterMmap) && pFd->pMethods->iVersion>=3 ){
+  if( nByte<=(i64)(db->nMaxSorterMmap) && pFd->pMethods->iVersion>=3 
+   && pFd->pMethods->xFetch
+  ){
     void *p = 0;
     int chunksize = 4*1024;
     sqlite3OsFileControlHint(pFd, SQLITE_FCNTL_CHUNK_SIZE, &chunksize);