Re: Bug in GNU Awk 3.1.5

[Jürgen Kahrs]

Filip Gieszczykiewicz wrote:

> Triggered by:
> ls /usr/lib/* | grep -v "/" | awk '{if (length($1) > 14) {print $1}}'

Thanks for boiling the problem down to a one-liner.

> Get dump:
> *** glibc detected *** awk: double free or corruption (fasttop):
> 0x083b78f8 ***
> ======= Backtrace: =========
> /lib/libc.so.6[0x890efd]
> /lib/libc.so.6(cfree+0x90)[0x894550]

This problem can indeed be reproduced with GNU Awk
3.1.5 as supplied since August 2005 at

  http://ftp.gnu.org/gnu/gawk/gawk-3.1.5.tar.gz

> Stock Fedora Core 6:
> Linux localhost.localdomain 2.6.18-1.2798.fc6 #1 SMP Mon Oct 16 14:54:20
> EDT 2006 i686 athlon i386
> GNU/Linux

This problem does _not_ appear after applying the patches
to 3.1.5 that Arnold posted here.
This problem does _not_ appear with the properly patched
gawk-3.1.5-41 that comes with SuSE Linux 10,2.

uname -a
Linux linux 2.6.18.2-34-default #1 SMP Mon Nov 27 11:46:27 UTC 2006 i686 athlon 
i386 GNU/Linux

> I plead ignorance to knowing how to debug stuff in a pipe with gdb.
> Can duplicate 100% reliably - which is why I had to convert that to a
> perl one-liner :)

Applying the maintainer's patches solves the problem.
No need to fall back to any non-standard tool.