Subject: Re: segfault in completion for configure
From: Peter Stephenson <[email-masked]>
To: [email-masked]
Date: Fri, 11 Mar 2016 14:32:02 +0000
List-Id: Zsh Workers List <zsh-workers.zsh.org>

On Fri, 11 Mar 2016 14:47:29 +0100
Vincent Lefevre <[email-masked]> wrote:
> With zsh 5.2 under Debian/unstable, zsh sometimes crashes when
> I do:
> 
> cventin:~/software/mutt/mutt> ./configure --[TAB]

> #0  0x000000000046f315 in charrefinc (x=0x6c58b8 <patinput>, y=0x7fd0f708c3c4 <error: Cannot access memory at address 0x7fd0f708c3c4>, z=0x7ffd49191418) at ../../Src/pattern.c:1937
>         wc = 0 L'\000'
>         ret = <optimized out>

Looks like something's already gone wrong by this point, since

> #1  0x0000000000472a0a in patmatch (prog=prog@entry=0xa00948) at ../../Src/pattern.c:2718
>         savpatinput = 0x7fd0f708c3b8 <error: Cannot access memory at address 0x7fd0f708c3b8>

this has remembered the value of an apparently invalid previous value of
patinput up above... although that's not guaranteed, since it may
simply be pointing to tne end of memory, which is valid as long as it's
not dereferenced (I had this while debugging a few months ago).

Does valgrind give any information?

pws