(tar-mode-revert): Cope if user cancels the revert.

1 files changed, 13 insertions, 5 deletions

diff --git a/lisp/tar-mode.el b/lisp/tar-mode.el
index ce8ed3b6184..9ac9eb90e08 100644
--- a/lisp/tar-mode.el
+++ b/lisp/tar-mode.el
@@ -630,11 +630,19 @@ appear on disk when you save the tar-file's buffer."
 
 ;; Revert the buffer and recompute the dired-like listing.
 (defun tar-mode-revert (&optional no-autosave no-confirm)
-  (setq tar-header-offset nil)
-  (let ((revert-buffer-function nil))
-    (revert-buffer t no-confirm)
-    (widen))
-  (tar-mode))
+  (let ((revert-buffer-function nil)
+        (old-offset tar-header-offset)
+        success)
+    (setq tar-header-offset nil)
+    (unwind-protect
+        (and (revert-buffer t no-confirm)
+             (progn (widen)
+                    (setq success t)
+                    (tar-mode)))
+      ;; If the revert was canceled,
+      ;; put back the old value of tar-header-offset.
+      (or success
+          (setq tar-header-offset old-offset)))))
 
 
 (defun tar-next-line (p)