Bug#616667: X server crash due to "xauth generate" with large timeout

[Ian Jackson <ijackson@chiark.greenend.org.uk>]

Package: xserver-xorg
Version: 1:7.5+8

To reproduce:
 cp .Xauthority private/tmpfile
 xauth -f private/tmpfile generate $DISPLAY . untrusted timeout 1000000000

Actual behaviour:
My X server died.  The log message was:
 X: ../../Xext/security.c:323: SecurityAuthorizationExpired: Assertion `pAuth->timer == timer' failed.
 XIO:  fatal IO error 11 (Resource temporarily unavailable) on X server ":0.0"
       after 7385 requests (7224 known processed) with 0 events remaining.

Desired behaviour:
X auth cookie is replaced in private/tmpfile and X server does not
crash.  Alternatively, an error message (eg, that the timeout is too
large, or that the X request failed).

I was trying to make an untrusted cookie which would not time out.
Unfortunately that does not appear to be possible.  A timeout value of
1000000 seems to work; 10000000 crashes the server.

Ian.