Bug#617208: Fails if started by init

[Julien Cristau <jcristau@debian.org>]

On Mon, Mar  7, 2011 at 11:52:01 +0100, Sven Joachim wrote:

> On 2011-03-07 09:21 +0100, Sven Joachim wrote:
> 
> > This morning I found myself at the console rather than at the XDM login
> > prompt, with the following messages in /var/log/xdm.log:
> >
> > ,----
> > | Mon Mar  7 07:50:32 2011 xdm error (pid 1285): Unknown session exit code 2816 from process 1463
> > | Mon Mar  7 07:50:33 2011 xdm info (pid 1285): Exiting
> > `----
> 
> In /var/log/messages, I can see that it actually segfaults:
> 
> ,----
> | Mar  7 07:50:32 turtle kernel: [   18.630173] xdm[1463]: segfault at a8 ip 00000000f763fdd5 sp 00000000ff816080 error 4 in libXt.so.6.0.0[f7627000+4e000]
> `----
> 
> > - Downgrading cpp to version 4:4.4.5-2 makes no difference, and other
> >   packages upgraded/installed/removed yesterday do not seem to have any
> >   relationship to xdm.
> 
> It seems I did not get enough sleep last night, because I overlooked the
> libxt6 upgrade.  Downgrading libxt6 to 1:1.0.9-2 fixes the problem.
> 
Looks like I can reproduce this...

Core was generated by `-:0         '.
Program terminated with signal 11, Segmentation fault.
#0  XtOpenDisplay (app=0x0, displayName=0x81e5798 ":0", 
    applName=0x8062326 "xlogin", className=0x806231f "Xlogin", urlist=0x0, 
    num_urs=0, argc=0x8065e4c, argv=0x8063bf8) at ../../src/Display.c:304
304     ../../src/Display.c: No such file or directory.
        in ../../src/Display.c

Not a clue why app is NULL there.  Or why this works fine after boot.

Cheers,
Julien