Bug#506840: exim4-daemon-heavy: relative symlinks may have negative effects (/usr/lib/exim4/exim4)

[Peter Gervai]

Package: exim4-daemon-heavy
Version: 4.63-17
Severity: minor

(Report is about 4.63-17 but as far as I see it si present in 4.69-9 as
well.)

There are some relative symlinks in the package tree:

debian:/storage/tmp# ls -la /usr/lib/{exim4,sendmail} 
lrwxrwxrwx 1 root root 13 2008-10-30 10:28 /usr/lib/sendmail -> ../sbin/exim4

/usr/lib/exim4:
total 256
drwxr-xr-x   3 root root     52 2008-10-30 10:38 .
drwxr-xr-x 402 root root 131072 2008-11-21 13:48 ..
lrwxrwxrwx   1 root root     16 2008-10-30 10:28 exim4 -> ../../sbin/exim4
-rwxr-xr-x   1 root root  65300 2008-09-30 20:27 eximon.bin
drwxr-xr-x   2 root root      6 2004-03-28 19:49 local_scan
debian:/storage/tmp# 



On a particular machine there are some symlinks around:

particular:/usr/lib/exim4# ls -la /usr/
total 64
drwxr-xr-x  10 root root  4096 2008-05-20 14:13 .
drwxr-xr-x  18 root root  4096 2008-05-20 14:08 ..
drwxr-xr-x   2 root root 20480 2008-09-02 15:09 bin
drwxr-xr-x   2 root root  4096 2008-05-20 12:56 doc
drwxr-xr-x   2 root root  4096 2008-05-20 12:56 games
drwxr-xr-x  37 root root  8192 2008-08-14 11:38 include
lrwxrwxrwx   1 root root    13 2008-05-20 14:13 lib -> /var/usr2/lib
drwxr-xr-x   3 root root  4096 2008-05-20 12:57 lib64
lrwxrwxrwx   1 root root    15 2008-05-20 14:09 local -> /var/usr2/local
drwxr-xr-x   2 root root  8192 2008-09-02 15:09 sbin
drwxr-xr-x 125 root root  4096 2008-05-20 14:13 share
lrwxrwxrwx   1 root root    13 2008-05-20 13:40 src -> /var/usr2/src
drwxr-xr-x   3 root root  4096 2008-05-20 12:55 X11R6


This causes exim not to start, since doing ../../sbin on /usr/lib/exim4 ends up
in /var/usr2/sbin which in turn does not exist.


Now, I do not want to argue about this being a _bug_, because frankly I cannot really
tell. 

First, it should be a bug since the package should not depend on
assumptions outside his scope (namely that a directory is or isn't a
symlink). 

Second, this should not be a bug since a manually unchanged Debian
should never contain symlinks on base directories. 

Third, this should not be a bug since Mr. Problem-between-keyboard-and-chair should 
not selectively symlink the directories (which, I'm happy to share: wasn't me).

Still, if there wasn't a good reason to have it relative, you might want to
make them absolute symlinks, because it would not possess this problem.

Thanks for reading my medium-length essay. ;-)

(Symlinks are fun things.)