Re: Emacs hangs enabling debug-on-error

[Kim F. Storm]

address@hidden (Kim F. Storm) writes:

> Robert Mecklenburg <address@hidden> writes:
>
> > KFS> Can you then try to identify which tool-bar item is involved
> > KFS> here, and possibly which lisp package added that toolbar binding.
> >
> > I've verified that debug-on-error works as expected if I do not load
> > vm 7.18!
>
> Ok, I have a test case which can reproduce this error consistently.

Test case:

Start emacs -q, and then evaluate the following:

(setq debug-on-error t)

(define-key tool-bar-map [tt-exit]
  '(menu-item
    "TEST"
    vm-toolbar-next-command
    :enable (vm-toolbar-any-messages-p)
    :button (:toggle nil)
    :image (image :type xpm :mask heuristic :file "../lisp/toolbar/alias.xpm")))


>
> It was ok 2 years ago, but it failed with CVS emacs from 1 year ago.
> I'll try to narrow down when it happened.

Reverting the following change fixes it:

2003-04-23  Jan Djärv  <address@hidden>

        * xdisp.c (update_tool_bar): BLOCK_INPUT before calling
        tool_bar_items so GTK tool bar expose callback does not access items
        being updated.


Problem is that emacs is looping inside tool_bar_items in a
Fsignal / redisplay / tool_bar_items...  loop.

However, we need a more radical fix as we really need to stop processing
tool-bar items when one of them is bogus; I'll look into ways to do that.

Maybe something like the way we handle memory-full.

--
Kim F. Storm  http://www.cua.dk