Bug#350208: sshd can't keep track of which DISPLAYs are in use

[Terran Melconian <terran@consistent.org>]

Package: ssh
Version: 3.8.1p1-8.sarge.4

When connecting to sshd, it appears that sshd fails to keep track of
which displays are already in use, and reassigns these to new
connections even though they are not actually available.  When I SSH
into the machine, the first connection is given display
machinename:10.  Then the second concurrent connection is also given
machinename:10.  So is the third.  This is obviously undesirable and
does not work very well.

I experience this problem only when X11UseLocalhost is set to "no";
when it is set to "yes", sshd is apparently able to keep track of
which displays are in use.

I did not have this problem with 3.4; this is new since I upgraded.