If the sorter uses mmap'd temp files, ensure all pages of the temp file have been allocated before it is accessed. Otherwise, a disk-full condition might result in a SIGBUS exception.

FossilOrigin-Name: 776648412c30dce206f1024ff849c2cb025bb006

1 files changed, 4 insertions, 4 deletions

diff --git a/src/os_unix.c b/src/os_unix.c
index a9344ee83..8314e4f67 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3718,16 +3718,16 @@ static int fcntlSizeHint(unixFile *pFile, i64 nByte){
       int nBlk = buf.st_blksize;  /* File-system block size */
       i64 iWrite;                 /* Next offset to write to */
 
-      if( robust_ftruncate(pFile->h, nSize) ){
-        pFile->lastErrno = errno;
-        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
-      }
       iWrite = ((buf.st_size + 2*nBlk - 1)/nBlk)*nBlk-1;
       while( iWrite<nSize ){
         int nWrite = seekAndWrite(pFile, iWrite, "", 1);
         if( nWrite!=1 ) return SQLITE_IOERR_WRITE;
         iWrite += nBlk;
       }
+      if( robust_ftruncate(pFile->h, nSize) ){
+        pFile->lastErrno = errno;
+        return unixLogError(SQLITE_IOERR_TRUNCATE, "ftruncate", pFile->zPath);
+      }
 #endif
     }
   }