Bug#960478: xorg-server: Allow XDMCP keepalives to be disabled

[<herbert@gondor.apana.org.au>]

Package: xorg-server
Version: 2:1.20.4-1
Severity: wishlist

As it is, when an XDMCP session is used over TCP keepalive packets
are periodically sent and the session is torn down if no replies
come back.

During a transient network failure, this causes an X session that
could otherwise survive just fine to be terminated prematurely.

While some may wish for this behaviour, perhaps to avoid a locked-up
X terminal, it would be nice if there was an option to either
extend the timeout so that failures of a few minutes do not cause
the session to be torn down, or even better just disable the
keepalives altogether.

-- System Information
Debian Release: 10.3
Kernel Version: Linux gwarestrin 5.2.0+ #3 SMP PREEMPT Tue Aug 20 22:11:45 AEST 2019 x86_64 GNU/Linux