Firefox/Wayland: Drag and Drop fails
Affected version
Fedora 33 / Wayland / Gnome mutter-3.38.3-1.fc33.x86_64 firefox-85.0.1-2.fc34.x86_64 (it's not important)
Bug summary
Mozilla BZ: https://bugzilla.mozilla.org/show_bug.cgi?id=1622107
After performing some D&D operations, wl_data_device::start_drag() call is silently cancelled. There's no information about failed/cancelled D&D. This may be as well as Gtk3 bug when we call gtk_drag_begin() but the returned context is 'dead'.
Steps to reproduce
Open Firefox on Fedora 33 / Gnome / Wayland. Select a text on webpage and move it by mouse (do D&D) for some time. It usually takes 5-10x try until D&D is blocked and Firefox does not do any D&D again. It's because Firefox things the D&D is still running and we don't get info about D&D abortion or so.
Complete Wayland log. Look for last 'wl_data_device@22.start_drag' string - this is the failed D&D operation.