Comment # 5 on bug 1039756 from Dominique Leuenberger

(In reply to Dingzhong Chen from comment #4)
> Is another bug report https://bugzilla.gnome.org/show_bug.cgi?id=773371
> related to this���

No, that is unrelated - the default.desktop implementation is kinda specific to
openSUSE in this case (wayland over X is prference in GDM, and default.desktop
won't change that)

> I have installed both GNOME and iceWM. GNOME was chosen during the system
> installation, but iceWM came with it.
> So if I try to enable autologin with GNOME on x.org, it behaves like the bug
> I mentioned above. Removed iceWM, GDM autologin becomes normal.

That one CAN be related, yes - depending on how the setup was installed (if the
user did not chose GNOME Desktop in the role selection, then yast leaves'
default' in the WM choser, which would then pick icewm, as gnome-shell does not
(yet) register as default handler...