(dired-unmark-all-files): Read arg as just a character.

Use non-regexp search to find a specific mark.
Use subst-char-in-region to make the change.
Improve the message at the end.

1 files changed, 22 insertions, 16 deletions

diff --git a/lisp/dired.el b/lisp/dired.el
index 9d0fd907eea..4cdc1dab066 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -1770,26 +1770,32 @@ OLD and NEW are both characters used to mark files."
                                 (match-end 0) old new))))))
 
 (defun dired-unmark-all-files (mark &optional arg)
-  "Remove a specific mark or any mark from every file.
+  "Remove a specific mark (or any mark) from every file.
+After this command, type the mark character to remove, 
+or type RET to remove all marks.
 With prefix arg, query for each marked file.
 Type \\[help-command] at that time for help."
-  (interactive "sRemove marks (RET means all): \nP")
-  (let ((count 0)
-        (re (if (zerop (length mark)) dired-re-mark
-              (concat "^" (regexp-quote mark)))))
-    (save-excursion
-      (let (buffer-read-only case-fold-search query
-                             (help-form "\
+  (interactive "cRemove marks (RET means all): \nP")
+  (save-excursion
+    (let* ((count 0)
+           buffer-read-only case-fold-search query
+           (string (format "\n%c" mark))
+           (help-form "\
 Type SPC or `y' to unmark one file, DEL or `n' to skip to next,
 `!' to unmark all remaining files with no more questions."))
-        (goto-char (point-min))
-        (while (re-search-forward re nil t)
-          (if (or (not arg)
-                  (dired-query 'query "Unmark file `%s'? "
-                               (dired-get-filename t)))
-              (progn (delete-char -1) (insert " ") (setq count (1+ count))))
-          (forward-line 1))))
-    (message "%s" (format "Marks removed: %d %s" count mark))))
+      (goto-char (point-min))
+      (while (if (eq mark ?\r)
+                 (re-search-forward dired-re-mark nil t)
+               (search-forward string nil t))
+        (if (or (not arg)
+                (dired-query 'query "Unmark file `%s'? "
+                             (dired-get-filename t)))
+            (progn (subst-char-in-region (1- (point)) (point)
+                                         (preceding-char) ?\ )
+                   (setq count (1+ count)))))
+      (message (if (= count 1) "1 mark removed"
+                 "%d marks removed")
+               count))))
 
 ;; Logging failures operating on files, and showing the results.