(diff-buffer-with-file): Call diff synchronously, so we don't delete

the temporary file before diff has a chance to read it.

1 files changed, 1 insertions, 1 deletions

diff --git a/lisp/files.el b/lisp/files.el
index ac25232bafe..ac61bbbd017 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -3008,7 +3008,7 @@ This requires the external program \"diff\" to be in your `exec-path'."
               (save-restriction
                 (widen)
                 (write-region (point-min) (point-max) tempfile nil 'nomessage)))
-            (diff buf-filename tempfile))
+            (diff buf-filename tempfile nil t))
         (when (file-exists-p tempfile)
           (delete-file tempfile)))
       nil)))