Xstartup handle DISPLAY=(null) correctly

[Adam Jackson]

On Mon, 2017-11-20 at 13:36 +0000, Emil Velikov wrote:
> On 20 November 2017 at 09:22, walter harms <wharms at bfs.de> wrote:
> > at what circumstances can DISPLAY == '(null)' ?
> > 
> > looks more like a bug in an Xserver.
> > 
> 
> The commit message should explain where/how such string originates and
> why the current solutions is preferred.
> Say bug is in A/B/other and fixing it in FOO allows all the buggy
> instances to be handled consistently.

The patch content itself is not going to be accepted, though. If
$DISPLAY is ever "(null)" then the _caller_ has done something
incorrectly, because that's not a valid display string. Working around
that in the xdm startup script does not fix the bug.

- ajax