Comment 6 for bug 1232804

https://github.com/ali1234/xfwm4/commit/b7baa7aa60cdb80759e0872d0ab5a7cb59ec5c10

This patch combined with the xsetroot patch for lightdm (above) fixes the issue, but isn't ideal, as it doesn't address the leaking pixmaps and non-standard atom use. It's along the general lines of what we need to do though.

Specifically my patch enables the root pixmap copy only at startup, and not the rest of the monitoring code. The monitoring code is what makes xfdesktop crash, because when it uses RetainPermanent, but does not create the pixmap with a dummy X11 connection like it should.