bug#15648: 24.2.50; gnutls SSL connection to IMAP server causes emacs to crash completely, bug#15648: 24.2.50; gnutls SSL connection to IMAP server causes emacs to crash completely

[Eli Zaretskii <eliz@gnu.org>]

> From: <emacs@kosowsky.org>
> Date: Wed, 23 Oct 2013 13:12:56 -0400
> Cc: emacs@kosowsky.org, tzz@lifelogs.com, 15648@debbugs.gnu.org
> 
> 4. This small patch to gnutls.el will fix the problem by expanding the
> file name to a full, valid path:

Sorry, but I cannot accept this.  There's absolutely no reason to run
the file through expand-file-name at that place.  More importantly,
there's no reason to believe this is the only place where the same
problem could surface.

>  > Windows supports Unix-style file names.  The problem is that the file
>  > "/usr/ssl/certs/ca-bundle.crt" cannot be found by starting from the
>  > root directory of the current drive.
> 
> The above proposed patch would fix that problem.

Only by sheer luck.

>  > > that being said the C-code should be better behaved than that... at
>  > > a minimum the code should check to make sure the certificate file
>  > > path is well-formed and exists.
>  > 
>  > See above: unless you present the backtrace from the crash, no one can
>  > know where the offending code is, or what it does wrong.  Please
>  > provide that data.
> 
> What do I need to do to get a backtrace?

Run Emacs under GDB, like this:

  gdb ./emacs.exe

When GDB finishes displaying its startup blurbs, just type "run", and
do whatever you do in Emacs to reproduce the problem.  When the
problem does happen, GDB will kick in, and you should type this at the
GDB prompt:

 (gdb) thread apply all bt

> I don't have any C-debugging software on my Windows laptop... and have
> never done C-code debugging in a Windows environment...

A Windows build of GDB suitable for this is available from the MinGW
site:

  http://sourceforge.net/projects/mingw/files/MinGW/Extension/gdb/gdb-7.6.1-1/gdb-7.6.1-1-mingw32-bin.tar.lzma/download