Re: [Emacs-diffs] ImageMagick Support on Windows

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 15 Oct 2014 11:27:36 +0200
> From: Alexander Shukaev <haroogan@gmail.com>
> Cc: emacs-devel@gnu.org
> 
>     Can you run this command under GDB, and see exactly where it crashes,
>     and why?
> 
> I, personally, usually don't use GDB to find out causes of crashing on Windows,
> i.e. I either infer them from the code or find it out through logging
> facilities. The main reason why I almost never use GDB on Windows is the
> following output:
> 
> Program received signal SIGSEGV, Segmentation fault.
> 0x0000000000000000 in ?? ()
> 
> which actually conveys no information at all. The crash often goes deep to some
> Windows system DLLs and therefore cannot be traced by GDB. This is exactly the
> case this time once again. We cannot rely on GDB now...

If you are sure the above was from thread #1, then there's only one
explanation: Emacs tried to call a function whose address was not yet
set by call GetProcAddress.

> Are you sure that you have pointed out all the spots that should be patched and
> that we didn't miss any of them? Please, since you know the internals better,
> think of what we could miss patching, it really feels like a zero pointer
> somewhere or something alike. In any case, now you know that it all starts from
> the "(imagemagick-register-types)" call.

I see someone else posted an explanation for the crash, so I think you
have a starting point.

Thanks.