Bug#233645: libxpm4: remove/purge hangs postrm

[Filip Van Raemdonck <mechanix@debian.org>]

Package: libxpm4
Version: 4.3.0-2
Severity: serious

Hi,

When removing libxpm4 (but I guess that depending on the order in which
apt removes them, any library from xfree86 could do this) the postrm
script hangs, waiting on input (observed from the fact that when it is
backgrounded it immediately goes to STOPPED state).

A quick look at the postrm script shows a few suspicious *greps, which
might get called with no file arguments and hence cause the hang.
Adding a set -x confirms this:

Removing libxpm4 ...
+ '[' remove = remove ']'
+ deregister_x_lib_dir_with_ld_so
+ local dir ldsoconf
+ dir=/usr/X11R6/lib
+ ldsoconf=/etc/ld.so.conf
+ fgrep -qsx /usr/X11R6/lib /etc/ld.so.conf
++ echo '/usr/X11R6/lib/lib*.so.*.*'
+ '[' '/usr/X11R6/lib/lib*.so.*.*' = '/usr/X11R6/lib/lib*.so.*.*' ']'
+ observe 'removing /usr/X11R6/lib directory from /etc/ld.so.conf'
+ '[' -n '' ']'
+ fgrep -qsvx /usr/X11R6/lib
dpkg: error processing libxpm4 (--purge):


So, in this case it's the second fgrep in deregister_x_lib_dir_with_ld_so.

Small note: I have only superficially looked at the postrm, but the
smoking_guns=$(grep ...) in find_culprits also looks suspicuous; I've
tried and if any of xbase-clients|xfree86-common|xfs|xlibs is installed
the possible_culprits variable is empty and so would cause the grep above
to hang, too, I believe. You may want to check that.


Regards,

Filip

-- 
Debian GNU/Linux --- no need to wait for tomorrow.