xwayland: pass focus to previous unmanaged surface on unmap

This is necessary because some applications (e.g. Jetbrains IDEs)
represent their multi-level menus as unmanaged surfaces, and when
closing a submenu, the main menu should get input focus.

Closes #5347.

sway/desktop/xwayland.c

@@ -94,6 +94,22 @@ static void unmanaged_handle_unmap(struct wl_listener *listener, void *data) {
 	struct sway_seat *seat = input_manager_current_seat();
 	if (seat->wlr_seat->keyboard_state.focused_surface ==
 			xsurface->surface) {
+
+		// Try to find another unmanaged surface from the same process to pass
+		// focus to. This is necessary because some applications (e.g. Jetbrains
+		// IDEs) represent their multi-level menus as unmanaged surfaces, and
+		// when closing a submenu, the main menu should get input focus.
+		struct sway_xwayland_unmanaged *current;
+		wl_list_for_each(current, &root->xwayland_unmanaged, link) {
+			struct wlr_xwayland_surface *prev_xsurface =
+				current->wlr_xwayland_surface;
+			if (prev_xsurface->pid == xsurface->pid &&
+					wlr_xwayland_or_surface_wants_focus(prev_xsurface)) {
+				seat_set_focus_surface(seat, prev_xsurface->surface, false);
+				return;
+			}
+		}
+
 		// Restore focus
 		struct sway_node *previous = seat_get_focus_inactive(seat, &root->node);
 		if (previous) {