Bug#187148: only one xdmcp connection

[Hadmut Danisch <hadmut@danisch.de>]

Package: xdm
Version: 4.2.1-6

Hi,

after doing the lastest sid upgrade, my xdm doesn't work
properly anymore. I have an Xserver with option -indirect to 
the host itself, where xdm provides a chooser, presenting the
host itself and all other machines willing to serve. That worked
well for several years. Now, the chooser still appears, but the
login service is unavailable.

Debugging showed that the xdm is (in contrast to older versions)
willing to answer only one xdmcp request and then shuts down 
the xdmcp socket (i.e. binds the socket to the Xserver, so it
doesn't accept other packets anymore). Since this first available
request is already taken by the chooser query, all subsequent 
queries are dropped. 

Even when starting a new xdm without the Xserver, it answers only
exactly one xdmcp request from other hosts.

regards
Hadmut