Subject: Re: bug#5973: Crash in get_next_display_element

From: Juanma Barranquero <[email-masked]>
Date: Tue, 20 Apr 2010 12:27:00 +0200

On Tue, Apr 20, 2010 at 11:56, Eli Zaretskii <[email-masked]> wrote:

> Instrument what? the defadvice, or something else?

The defadvice. In previous versions, the advice had more code, and
when you stepped through it, it crashed when trying to display the
value of END. With the shortened version, you don't get to step into
anything. As soon as the instrumented advice triggers, blam!

> Which lines did you select?  I think this is important, because
> when a form is evaluated, Edebug displays in the echo area a message
> showing the result of the evaluation, and if the result is a number,
> it tries to display it as a character.  So the end of the region you
> select determines what character will Edebug try to display.

A few lines at the start of the file, usually about ten or twenty.
AFAICS, the start of etc/NEWS does not contain any composable
character, just straight ASCII.

> I don't see this message, perhaps because I used a different region.

I use `force-load-messages' set to t.

Hmm. I got a reproducible recipe with -Q

   emacs -Q
   M-: (setq force-load-messages t) <RET>
   C-x C-f bug.el <RET>       ;; the file containing just the defadvice
   C-u C-M-x
   C-h n
   ;; select line 22
   C-x n n

    Juanma