widget-button-click chokes on frame selection event

widget-button-click chokes on frame selection event

[Andreas Seltenreich]

When a click on a widget button also switches frames, there's a chance
that it triggers the following error:

--8<---------------cut here---------------start------------->8---
Debugger entered--Lisp error: (wrong-type-argument listp #<frame emacs@tp 0xb4d9610>)
  posn-point(#<frame emacs@tp 0xb4d9610>)
  widget-event-point((switch-frame #<frame emacs@tp 0xb4d9610>))
  (setq pos (widget-event-point event))
  (while (not (widget-button-release-event-p event)) (setq event (read-event)) (when (and mouse-1 ...) (push event unread-command-events) (setq event oevent) (throw ... t)) (setq pos (widget-event-point event)) (if (and pos ...) (when face ... ...) (overlay-put overlay ... face) (overlay-put overlay ... mouse-face)))
  (let ((track-mouse t)) (while (not ...) (setq event ...) (when ... ... ... ...) (setq pos ...) (if ... ... ... ...)))
  (if (widget-apply button :mouse-down-action event) nil (let (...) (while ... ... ... ... ...)))
  (unless (widget-apply button :mouse-down-action event) (let (...) (while ... ... ... ... ...)))
  (save-excursion (when face (overlay-put overlay ... pressed-face) (overlay-put overlay ... pressed-face)) (unless (widget-apply button :mouse-down-action event) (let ... ...)) (when (and pos ...) (widget-apply-action button event)))
  (unwind-protect (save-excursion (when face ... ...) (unless ... ...) (when ... ...)) (overlay-put overlay (quote face) face) (overlay-put overlay (quote mouse-face) mouse-face))
  (let* ((overlay ...) (pressed-face ...) (face ...) (mouse-face ...)) (unwind-protect (save-excursion ... ... ...) (overlay-put overlay ... face) (overlay-put overlay ... mouse-face)))
  (save-excursion (goto-char (posn-point ...)) (let* (... ... ... ...) (unwind-protect ... ... ...)))
  (progn (select-window (posn-window ...)) (save-excursion (goto-char ...) (let* ... ...)))
  (unwind-protect (progn (select-window ...) (save-excursion ... ...)) (dolist (elt save-selected-window-alist) (and ... ... ...)) (if (window-live-p save-selected-window-window) (select-window save-selected-window-window)))
  (save-current-buffer (unwind-protect (progn ... ...) (dolist ... ...) (if ... ...)))
  (let ((save-selected-window-window ...) (save-selected-window-alist ...)) (save-current-buffer (unwind-protect ... ... ...)))
  (save-selected-window (select-window (posn-window ...)) (save-excursion (goto-char ...) (let* ... ...)))
  (catch (quote button-press-cancelled) (save-selected-window (select-window ...) (save-excursion ... ...)) nil)
  (or (null button) (catch (quote button-press-cancelled) (save-selected-window ... ...) nil))
  (if (or (null button) (catch ... ... nil)) (progn (let ... ... ... ...)))
  (when (or (null button) (catch ... ... nil)) (let (... command) (if mouse-1 ... ...) (when up ...) (when command ...)))
  (let* ((oevent event) (mouse-1 ...) (pos ...) (start ...) (button ...)) (when (or ... ...) (let ... ... ... ...)))
  (if (widget-event-point event) (let* (... ... ... ... ...) (when ... ...)) (message "You clicked somewhere weird."))
  widget-button-click((down-mouse-1 (#<window 3075 on *Widget Example*> 364 (56 . 210) -76405506 nil 364 (7 . 13) nil (0 . 2) (8 . 16))))
  call-interactively(widget-button-click)
--8<---------------cut here---------------end--------------->8---

I did not see it happen while working with multiple frames on a single
display yet, but it occurs frequently enough to be annoying when
working on multiple displays.

The attached patch fixes it for me.

regards,
andreas

2006-09-16  Andreas Seltenreich  <uwi7@rz.uni-karlsruhe.de>

	* wid-edit.el (widget-button-click): Don't call widget-event-point
	on non-mouse events to avoid error when a click triggered a
	switch-frame event.

Index: wid-edit.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/wid-edit.el,v
retrieving revision 1.166
diff -u -r1.166 wid-edit.el
--- wid-edit.el	16 Feb 2006 15:58:32 -0000	1.166
+++ wid-edit.el	16 Sep 2006 21:13:26 -0000
@@ -959,7 +959,9 @@
 				  (push event unread-command-events)
 				  (setq event oevent)
 				  (throw 'button-press-cancelled t))
-				(setq pos (widget-event-point event))
+				(if (or (mouse-movement-p event)
+					(widget-button-release-event-p event))
+				    (setq pos (widget-event-point event)))
 				(if (and pos
 					 (eq (get-char-property pos 'button)
 					     button))

Re: widget-button-click chokes on frame selection event

[Richard Stallman]

I don't know how to reproduce the problem, but I think I see what
is going wrong.  I am guessing how to fix it.  What results does
this give?

*** wid-edit.el	22 Feb 2006 13:56:50 -0500	1.166
--- wid-edit.el	17 Sep 2006 14:35:20 -0400	
***************
*** 959,973 ****
  				  (push event unread-command-events)
  				  (setq event oevent)
  				  (throw 'button-press-cancelled t))
! 				(setq pos (widget-event-point event))
! 				(if (and pos
! 					 (eq (get-char-property pos 'button)
! 					     button))
! 				    (when face
! 				      (overlay-put overlay 'face pressed-face)
! 				      (overlay-put overlay 'mouse-face pressed-face))
! 				  (overlay-put overlay 'face face)
! 				  (overlay-put overlay 'mouse-face mouse-face)))))
  
  			  ;; When mouse is released over the button, run
  			  ;; its action function.
--- 959,976 ----
  				  (push event unread-command-events)
  				  (setq event oevent)
  				  (throw 'button-press-cancelled t))
! 				(unless (or (integerp event)
! 					    (memq (car event) '(switch-frame select-window))
! 					    (eq (car event) 'scroll-bar-movement))
! 				  (setq pos (widget-event-point event))
! 				  (if (and pos
! 					   (eq (get-char-property pos 'button)
! 					       button))
! 				      (when face
! 					(overlay-put overlay 'face pressed-face)
! 					(overlay-put overlay 'mouse-face pressed-face))
! 				    (overlay-put overlay 'face face)
! 				    (overlay-put overlay 'mouse-face mouse-face))))))
  
  			  ;; When mouse is released over the button, run
  			  ;; its action function.

Re: widget-button-click chokes on frame selection event

[Andreas Seltenreich]

Richard Stallman <rms@gnu.org> writes:

> I don't know how to reproduce the problem, but I think I see what
> is going wrong.  I am guessing how to fix it.  What results does
> this give?

I've applied your patch and played with the example form in
(info "(widget)Programming Example") using frames on two displays for
about ten minutes.  I couldn't trigger the bug, and all the
functionality was there.  After reverting the patch, the error
occurred on the third click, so I'm confident that the fix is correct.

Thanks,
andreas