Re: Double free with latest updates

[Mikael Magnusson <mikachu@xxxxxxxxx>]

On Mon, May 4, 2015 at 1:20 PM, Vin Shelton <acs@xxxxxxxxxxxxxxxxxxxx> wrote:
> The most recent changes to builtin.c result in a double free in running the
> test suite.
>
> I have more details if you need them.
>
>   - Vin
>
> zsh
> remote: Counting objects: 9, done.
> remote: Compressing objects: 100% (5/5), done.
> remote: Total 5 (delta 4), reused 0 (delta 0)
> Unpacking objects: 100% (5/5), done.
> From git://zsh.git.sf.net/gitroot/zsh/zsh
>    5b00bfe..1e6fb1a  master     -> origin/master
> Updating 5b00bfe..1e6fb1a
> Fast-forward
>  ChangeLog     | 4 ++++
>  Src/builtin.c | 7 ++++---
>  2 files changed, 8 insertions(+), 3 deletions(-)
>
> Building zsh
> /opt/src/zsh-2015-05-04
> cd . && ./.preconfig
> Configuring zsh-2015-05-04 for installation prefix /opt/zsh-2015-05-04.
> Building zsh...done.
> Running tests...%
> print ten ten nine one print
>   print print one two three four five six seven eight nine ten one two
>   print mystery sequence
>   print one
>   print two
>   print mystery sequence
>   print metaphor\? shmetaphor!
>   print metaphor!
>   print -l metophor, Molochi,
>   echo $(echo foo bar) again
>   echo more $( echo $(echo foo bar) again )
> done.
> *** Error in `zsh': double free or corruption (out): 0x00007fff694af880 ***
>

Doesn't happen here with or without --enable-zsh-{mem,debug}. Valgrind
also didn't complain at all. Enable the MALLOC_CHECK_ flag that
enables backtrace on double free and see if it says anything useful.

"If MALLOC_CHECK_ is set to 0, any detected heap corruption is
silently ignored; if set to 1, a diagnostic is printed on stderr; if
set to 2, abort is called immediately."

-- 
Mikael Magnusson