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

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

diff --git a/lisp/delsel.el b/lisp/delsel.el
index 4301e69b61dcb0958d82180ffb945f0906df8d97..9488e94061e326084c9c6ca59d2b0534fd1beb1f 100644 (file)
--- 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)