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From: Chong Yidong <cyd@stupidchicken.com>
Newsgroups: gmane.emacs.devel
Subject: Re: [lekktu@gmail.com: Re: Crash when having malformed PBM image on
	screen and viewing *Messages* buffer (on Windows)]
Date: Mon, 06 Aug 2007 13:23:14 -0400
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Xref: news.gmane.org gmane.emacs.devel:76097
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> As I said in the original thread about this bug, the problem can be
> reproduced on GNU/Linux.  The recipe to reproduce it is:
>
> 	- start emacs -Q
> 	- run this in *scratch* buffer
>
> 	(progn
> 	  (put-image '(image :type pbm :data "") 0)
> 	  (pop-to-buffer "*Messages*")
> 	  (goto-char (point-max)))
>
> 	Now press <down> <right> <down> <right>.

The problem is that the size of the *Messages* buffer shrinks during
redisplay_window, as a result of message log truncation: from

...
unsigned char *) 0x85da2f8 "pe pbm :data )'
call-interactively: End of bufferNot a PBM image: `(image :type pbm :data )'
call-interactively: End of buffer

to

...
unsigned char *) 0x85da4cc "pe pbm :data )'
call-interactively: End of bufferNot a PBM image: `(image :type pbm :data )' [2 times]

I've checked in code into both the trunk and branch to handle this
corner case.