4a968c3b4e
When DnD is started from an X11 client, mutter now sets up an special grab that 1) Ensures the drag source keeps receiving events, and 2) Moves an internal X Window over wayland clients as soon as the pointer enters over these. That window will act as the X-side peer for the currently focused wayland client, and will transform XdndEnter/Position/Leave/Drop messages into wayland actions. If DnD happens between X11 clients, the window will be moved away and unmapped, to let these operate as usual. https://bugzilla.gnome.org/show_bug.cgi?id=738312