(Finsert_file_contents): Check for beginning of file.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 79bd39161af..e1131ce8860 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2712,6 +2712,9 @@ and (2) it puts less data in the undo list.")
 
           /* At what file position are we now scanning?  */
           curpos = st.st_size - (ZV - same_at_end);
+          /* If the entire file matches the buffer tail, stop the scan.  */
+          if (curpos == 0)
+            break;
           /* How much can we scan in the next step?  */
           trial = min (curpos, sizeof buffer);
           if (lseek (fd, curpos - trial, 0) < 0)