Small executable.el fix related to bug#9879.

* lisp/progmodes/executable.el
(executable-make-buffer-file-executable-if-script-p):
Handle file-modes returning nil.

2 files changed, 14 insertions, 6 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index ea27df043f..65ab83e020 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,9 @@
 2011-11-14  Glenn Morris  <[email protected]>
 
+	* progmodes/executable.el
+	(executable-make-buffer-file-executable-if-script-p):
+	Handle file-modes returning nil.
+
 	* mail/rmail.el (rmail-no-mail-p): Remove mode-line N/M indicator.
 
 	* mail/rmailsum.el (rmail-summary, rmail-new-summary)
diff --git a/lisp/progmodes/executable.el b/lisp/progmodes/executable.el
index d8133cb6b9..281fa3cef7 100644
--- a/lisp/progmodes/executable.el
+++ b/lisp/progmodes/executable.el
@@ -268,12 +268,16 @@ file modes."
        (save-restriction
 	 (widen)
 	 (string= "#!" (buffer-substring (point-min) (+ 2 (point-min)))))
-       (let* ((current-mode (file-modes (buffer-file-name)))
-              (add-mode (logand ?\111 (default-file-modes))))
-         (or (/= (logand ?\111 current-mode) 0)
-             (zerop add-mode)
-             (set-file-modes (buffer-file-name)
-                             (logior current-mode add-mode))))))
+       (condition-case nil
+           (let* ((current-mode (file-modes (buffer-file-name)))
+                  (add-mode (logand ?\111 (default-file-modes))))
+             (or (/= (logand ?\111 current-mode) 0)
+                 (zerop add-mode)
+                 (set-file-modes (buffer-file-name)
+                                 (logior current-mode add-mode))))
+         ;; Eg file-modes can return nil (bug#9879).  It should not,
+         ;; in this context, but we should handle it all the same.
+         (error (message "Unable to make file executable")))))
 
 (provide 'executable)