Bug#775730: iceweasel: unhandled symlink to directory conversion: /usr/lib/iceweasel/defaults

[Mike Hommey]

On Mon, Jan 19, 2015 at 12:36:54PM +0100, Andreas Beckmann wrote:
> Package: iceweasel
> Version: 31.4.0esr-1
> Severity: serious
> User: debian-qa at lists.debian.org
> Usertags: piuparts
> 
> Hi,
> 
> an upgrade test with piuparts revealed that your package installs files
> over existing symlinks and possibly overwrites files owned by other
> packages. This usually means an old version of the package shipped a
> symlink but that was later replaced by a real (and non-empty)
> directory. This kind of overwriting another package's files cannot be
> detected by dpkg.
> 
> This was observed on the following upgrade paths:
> 
>   squeeze -> wheezy -> jessie
> 
> For /usr/share/doc/PACKAGE this may not be problematic as long as both
> packages are installed, ship byte-for-byte identical files and are
> upgraded in lockstep. But once one of the involved packages gets
> removed, the other one will lose its documentation files, too,
> including the copyright file, which is a violation of Policy 12.5:
> https://www.debian.org/doc/debian-policy/ch-docs.html#s-copyrightfile
> 
> For other overwritten locations anything interesting may happen.
> 
> Note that dpkg intentionally does not replace directories with symlinks
> and vice versa, you need the maintainer scripts to do this.
> See in particular the end of point 4 in
> https://www.debian.org/doc/debian-policy/ch-maintainerscripts.html#s-unpackphase
> 
> It is recommended to use the dpkg-maintscript-helper commands
> 'dir_to_symlink' and 'symlink_to_dir' (available since dpkg 1.17.14)
> to perform the conversion, ideally using d/$PACKAGE.mainstscript.
> Do not forget to add 'Pre-Depends: ${misc:Pre-Depends}' in d/control.
> See dpkg-maintscript-helper(1) and dh_installdeb(1) for details.
> 
> 
> >From the attached log (usually somewhere in the middle...):
> 
> 6m28.1s INFO: dirname part contains a symlink:
>   /usr/lib/iceweasel/defaults/pref (iceweasel) != /usr/share/iceweasel/defaults/pref (?)
>     /usr/lib/iceweasel/defaults -> ../../share/iceweasel/defaults
>   /usr/lib/iceweasel/defaults/pref/channel-prefs.js (iceweasel) != /usr/share/iceweasel/defaults/pref/channel-prefs.js (?)
>     /usr/lib/iceweasel/defaults -> ../../share/iceweasel/defaults

What piuparts fails to see is that /usr/share/iceweasel/defaults/pref
belonged to iceweasel. Is it still a serious bug in that case? Sure, it
would be good to fix it, the question is whether it is RC or not.

Mike