Reset default size of desktop window to -1 in GTK 3.19/20 only. The combination of a non-resizable window with a default size is what causes the desktop to open wrong size. based on https://github.com/GNOME/nautilus/commit/cf79068dc70c87e963e217e2e8ae149ee5ed1872 "desktop-window: avoid wrong size" "gtk+ recently changed and unresizable windows now take into account the default size set. We set the default size for normal resizable windows in nautilus." "However the desktop window is a no resizable window. What happens now when setting a default size is that that size is used instead of the widget request size, since window sizing now takes precedence over widget sizing." "To fix it, set the default size to -1 to override what the nautilus window does by default, so we can avoid this misbehaviour."