Subject: Re: bug#23704: 25.1.50; Emacs crash in syntax.c

From: [email-masked] (Vincent Belaïche)
Date: Mon, 06 Jun 2016 18:14:18 +0200

Dear Eli,

Sorry for not running an unoptimized version...

Le 06/06/2016 à 16:49, Eli Zaretskii a écrit :
>> From: [email-masked] (Vincent Belaïche)
>> Date: Mon, 06 Jun 2016 07:25:49 +0200
>> Cc: Vincent Belaïche <[email-masked]>
>>
>> This is a very difficult to reproduce crash. It happens quite scarcely,
>> but fortunately, knowing its existence I was running under the
>> debugger. Please note that it was w/o the -Q option, and my init file is
>> quite a few lines ;-).
>
> Thanks.
>
> Unfortunately, backtraces from optimized builds, even those with -Og
> switch, are not reliable enough.  So when you know about an existing
> problem that is hard to reproduce, please run an unoptimized version
> if you can.
>
> Nevertheless, let's see if we can glean anything useful from this
> crash.  Please show the output of these GDB commands:
>
>   (gdb) p PT_ADDR
>   (gdb) p GPT_ADDR
>   (gdb) p GPT

Here you are:

--8<----8<----8<----8<----8<-- begin -->8---->8---->8---->8---->8----
(gdb) p PT_ADDR
$1 = (unsigned char *) 0x521073e " long as we don't have any longer the \\NEWLINE the problem is solved. So it could be:\n\n\n\n--8<----8<----8<----8<----8<-- begin -->8---->8---->8---->8---->8----\n  in_input_funnies=`echo \"$in_input\" \\\n  "...
(gdb)  p GPT_ADDR
$2 = (unsigned char *) 0x5210677 ""
(gdb) p GPT
$3 = 1651
--8<----8<----8<----8<----8<--  end  -->8---->8---->8---->8---->8----

The PT_ADDR seems to be pointing at the content of an email that I was
editing when the crash occurred --- fortunately nothing confidential
-)), some discussion in Texinfo bug mailing list, concerning support for
spaces in filenames. If you are interested the thread is titled:

   REVIEW REQUEST - user manual generation

I have also attached a screen capture of crashed Emacs, that may help
you see what the content of the edited buffer was when the crash
occurred. It seems that the crash occurred while I was editing the
sentence « So it could be: ... ».

VBR,
	Vincent.