Comment # 5 on bug 906622 from Luigi Baldoni

(In reply to Egbert Eich from comment #3)
> On SUSE you should have XAUTHLOCALHOSTNAME set - at least when you use KDE
> and log in thru KDM. With this everything should be fine. At least here I
> can set my hostname to whatever I want without any access issues.
> Please provide the output of:
>   - 'hostname'
>   - 'echo $XAUTHLOCALHOSTNAME'
>   - 'xauth -n list'
> 
> Then disable your wired network and obtain the output of 'hostname' again.
> 
> If the output of 'echo $XAUTHLOCALHOSTNAME' is empty, do an 'export
> XAUTHLOCALHOSTNAME=`hostname` before you kill your network and see if this
> makes a difference.

See attachment. I sanitised the contents, but I hope it won't be a problem.

Setting XAUTHLOCALHOSTNAME to myhost.mydomain instead of myhost makes no
difference (Invalid MIT-MAGIC-COOKIE-1 in both cases).