(delete-selection-pre-hook): Handle and resignal

file-supersession errors to interact properly with userlock.el.

1 files changed, 25 insertions, 18 deletions

diff --git a/lisp/delsel.el b/lisp/delsel.el
index 4301e69b61d..9488e94061e 100644
--- a/lisp/delsel.el
+++ b/lisp/delsel.el
@@ -84,24 +84,31 @@ any selection."
              (not buffer-read-only))
     (let ((type (and (symbolp this-command)
                      (get this-command 'delete-selection))))
-      (cond ((eq type 'kill)
-             (delete-active-region t))
-            ((eq type 'yank)
-             ;; Before a yank command,
-             ;; make sure we don't yank the same region
-             ;; that we are going to delete.
-             ;; That would make yank a no-op.
-             (when (string= (buffer-substring-no-properties (point) (mark))
-                            (car kill-ring))
-               (current-kill 1))
-             (delete-active-region))
-            ((eq type 'supersede)
-             (let ((empty-region (= (point) (mark))))
-               (delete-active-region)
-               (unless empty-region
-                 (setq this-command 'ignore))))
-            (type
-             (delete-active-region))))))
+      (condition-case data
+          (cond ((eq type 'kill)
+                 (delete-active-region t))
+                ((eq type 'yank)
+                 ;; Before a yank command,
+                 ;; make sure we don't yank the same region
+                 ;; that we are going to delete.
+                 ;; That would make yank a no-op.
+                 (when (string= (buffer-substring-no-properties (point) (mark))
+                                (car kill-ring))
+                   (current-kill 1))
+                 (delete-active-region))
+                ((eq type 'supersede)
+                 (let ((empty-region (= (point) (mark))))
+                   (delete-active-region)
+                   (unless empty-region
+                     (setq this-command 'ignore))))
+                (type
+                 (delete-active-region)))
+        (file-supersession
+         ;; If ask-user-about-supersession-threat signals an error,
+         ;; stop safe_run_hooks from clearing out pre-command-hook.
+         (and (eq inhibit-quit 'pre-command-hook)
+              (setq inhibit-quit 'delete-selection-dummy))
+         (signal 'file-supersession (cdr data)))))))
 
 (put 'self-insert-command 'delete-selection t)
 (put 'self-insert-iso 'delete-selection t)