Re: Assertion image->cache != (Cache) ((void *)0)' failed.

On Thu, 13 Mar 2008, Micha? Kowalczuk wrote:

> Hello,
> I found a bug in GraphicsMagick. It happened when I tried to scale this jpeg
> file: http://kowalczuk.eu/other/GM-bug.jpg
>
> $ gm convert -scale 800 GM-bug.jpg test.jpg
> gm: cache.c:534: AcquireImagePixels: Assertion `image->cache != (Cache) ((void *)0)' failed.

GraphicsMagick CVS (1.1 branch and 1.2 HEAD) and the latest GM 1.2 
snapshot now contain a fix for this problem.

> In utility.c, function TranslateText():
>
>      case '#':
>      {
>        if (!image->cache) {
>          *q++=(*p);
>          continue;
>        }
>
> But I think that the main problem is that gm is trying to clone the comment
> when there isn't one in the source file. Also, checking existence of cache
> before calling SignatureImage() is also not a bad idea.

It seems that you are using an old GraphicsMagick version.  It was not 
sufficient to test for image->cache since it is allocated when the 
image is first allocated.

The actual problem I noticed is that the JPEG attributes are 
processed before the pixels have been initialized.

Bob
======================================
Bob Friesenhahn
[email protected], http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/


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