Created attachment 210375 [details]
Example of an incorrectly positioned "rdesktop -D -g workarea" window.

Sometimes a program intentionally opens a window that is not technically maximized, but nevertheless occupies as much space as possible, leaving zero space between the window border and the screen border. With latest Mutter, those windows can be positioned incorrectly.

In this particular case, I'm using a Remote Desktop client by running

    rdesktop -D -g workarea <hostname>

which opens an undecorated window ("-D") and uses the largest possible area ("-g workarea"), allowing the remote session to occupy my entire desktop except the GNOME Shell top bar. The session window is not resizable – the RDP protocol does not allow changing screen resolution. Since it lacks decorations, it is also unmovable and is intended to be positioned at top-left corner.

But with Mutter 3.3.92, this window is not positioned at the top-left corner, but instead a few cm away from it. Since rdesktop refuses to be resized, half of the window simply remains off-screen, making it very inconvenient to use. (See the attached screenshot.)

I realize that this rdesktop invocation is probably a corner case and/or rdesktop should be creating the window as maximized in the first place; nevertheless, it would be nice to have this working as previously, at least for such unresizable windows. (The new behavior does seem very useful in the other 99% cases.)

mutter 3.3.92-1
gnome-shell 3.3.92-1
Arch Linux [gnome-unstable]