Bugzilla Bug 166523

After a recent update, cfg-update stopped working; even though $DISPLAY was set
correctly, xxdiff was found in the correct location, etc. it still complained
with the following error:

* GUI not available, unable to run the mergetool set in /etc/cfg-update.conf!
  Run cfg-update from within an X-terminal if you want to use a GUI mergetool.
  If you are getting this from within an X-terminal, you should try running
  "xhost +localhost" as the user who started the X-server.
  If you use this script on a system without an X-server you should permanently
  set the MERGETOOL variable in /etc/cfg-update.conf to vimdiff or sdiff.
  I recommend the more advanced vimdiff on systems without an X-server.
  See http://people.zeelandnet.nl/xentric for vimdiff usage instructions.

After searching for explanations for some time, I used strace -f on it and
found the following:

[...]
[pid  3848] write(2, "sh: xhost: command not found\n", 29) = 29
[...]

And indeed, after emerging xhost, everything works fine. I think it should be
in the dependancies for cfg-update (not xxdiff, I assume, as that does work
without it).




Reproducible: Always

Steps to Reproduce:
1.ssh to a remote system
2.set $DISPLAY correctly
3.Remove xhost, if present
4.Run xxdiff (works)
5.Run cfg-update -u (fails)
6.emerge xhost
7.Run cfg-update -u (works)



Expected Results:  
Either xhost should be in the deps for cfg-update, but that may be overkill as
it is only needed if run from a remote system, or it should clearly display an
error that it couldn't find xhost.

Thanks, I've added xhost to the dependency list.