gdm-3.6.2 doesn't have autologin-once feature

[piotr5]

did anyone find a workaround for this?
what I want: directly after reboot, and only there I want X to start with the desktop of my choice and my username logged in without password.
if I choose gnome as my desktop I want gdm to lock the screen upon inactivity and require my password.
if I log out I want that a usual gdm session is asking for username (choice already remembered as usual) and my password.

any suggestions how to achieve that? using autologinenable=true in my /etc/gdm/custom.conf results in an inability to log in after log out -- no password is asked for and instead gdm somehow restarts. should I create a program that changes /etc/gdm/custom.conf before and after startup and something that restarts gdm (with gdm stop;gdm start) once I log out? any other suggestions? wasn't there once a gdm-patch that enabled this functionality?