(hi-lock-unface-buffer): If a menu of regexps is

popped up, but the user clicks outside the menu, return an empty
regexp (that causes unhighlight-regexp to have no effect).

1 files changed, 25 insertions, 16 deletions

diff --git a/lisp/hi-lock.el b/lisp/hi-lock.el
index f5606d7e445..f2a77b620c7 100644
--- a/lisp/hi-lock.el
+++ b/lisp/hi-lock.el
@@ -346,25 +346,34 @@ list maintained for regexps, global history maintained for faces.
 
 Interactively, prompt for REGEXP.  Buffer-local history of inserted
 regexp's maintained.  Will accept only regexps inserted by hi-lock
-interactive functions. (See `hi-lock-interactive-patterns')
+interactive functions. \(See `hi-lock-interactive-patterns'.\)
 \\<minibuffer-local-must-match-map>Use \\[minibuffer-complete] to complete a partially typed regexp.
-(See info node `Minibuffer History'.)"
+\(See info node `Minibuffer History'.\)"
   (interactive
    (if (vectorp (this-command-keys))
-       (x-popup-menu
-        t
-        (cons
-         `keymap
-         (cons "Select Pattern to Unhighlight"
-               (mapcar (lambda (pattern)
-                         (list (car pattern)
-                               (format
-                                "%s (%s)" (car pattern)
-                                (symbol-name
-                                 (car (cdr (car (cdr (car (cdr pattern))))))))
-                               (cons nil nil)
-                               (car pattern)))
-                       hi-lock-interactive-patterns))))
+       (catch 'snafu
+         (or
+          (x-popup-menu
+           t
+           (cons
+            `keymap
+            (cons "Select Pattern to Unhighlight"
+                  (mapcar (lambda (pattern)
+                            (list (car pattern)
+                                  (format
+                                   "%s (%s)" (car pattern)
+                                   (symbol-name
+                                    (car
+                                     (cdr (car (cdr (car (cdr pattern))))))))
+                                  (cons nil nil)
+                                  (car pattern)))
+                          hi-lock-interactive-patterns))))
+          ;; If the user clicks outside the menu, meaning that they
+          ;; change their mind, x-popup-menu returns nil, and
+          ;; interactive signals a wrong number of arguments error.
+          ;; To prevent that, we return an empty string, which will
+          ;; effectively disable the rest of the function.
+          (throw 'snafu '(""))))
      (let ((history-list (mapcar (lambda (p) (car p))
                                  hi-lock-interactive-patterns)))
        (unless hi-lock-interactive-patterns