[mutter/gnome-3-22] xwayland: Release xdnd grabs ASAP

[Carlos Garnacho <carlosg src gnome org>]

commit 9bd4fd7b981d7aa435960e267969d96e6c130fba
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Mar 7 20:00:20 2017 +0100

    xwayland: Release xdnd grabs ASAP
    
    We currently wait for the selection being cleared by the drag source,
    which might not happen on not quite educated clients. This may leave
    a stuck XDND grab in the compositor side.
    
    We can actually do a bit better, and clear the grab if:
    1) The drag source sent XdndDrop to the wayland drag destination.
    2) There's no accepting drag destination and all pointer buttons are
       released.
    3) As usual, whenever the drag source clears the selection data
    
    https://bugzilla.gnome.org/show_bug.cgi?id=763246

 src/wayland/meta-xwayland-selection.c |   27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)
---
diff --git a/src/wayland/meta-xwayland-selection.c b/src/wayland/meta-xwayland-selection.c
index d2a6e94..f739eeb 100644
--- a/src/wayland/meta-xwayland-selection.c
+++ b/src/wayland/meta-xwayland-selection.c
@@ -388,6 +388,20 @@ meta_xwayland_shutdown_dnd (MetaXWaylandManager *manager)
   dnd->dnd_window = None;
 }
 
+static void
+meta_xwayland_end_dnd_grab (MetaWaylandDataDevice *data_device)
+{
+  Display *xdisplay = GDK_DISPLAY_XDISPLAY (gdk_display_get_default ());
+  MetaWaylandCompositor *compositor = meta_wayland_compositor_get_default ();
+  MetaXWaylandManager *manager = &compositor->xwayland_manager;
+  MetaDndBridge *dnd = &manager->selection_data->dnd;
+
+  meta_wayland_data_device_end_drag (data_device);
+
+  XMoveResizeWindow (xdisplay, dnd->dnd_window, -1, -1, 1, 1);
+  XUnmapWindow (xdisplay, dnd->dnd_window);
+}
+
 /* X11/Wayland data bridges */
 
 static MetaSelectionBridge *
@@ -1400,8 +1414,16 @@ drag_xgrab_button (MetaWaylandPointerGrab *grab,
 {
   MetaWaylandCompositor *compositor = meta_wayland_compositor_get_default ();
   MetaWaylandSeat *seat = compositor->seat;
+  MetaWaylandDataSource *data_source;
 
   meta_wayland_pointer_send_button (seat->pointer, event);
+  data_source = compositor->seat->data_device.dnd_data_source;
+
+  if (seat->pointer->button_count == 0 &&
+      (!meta_wayland_drag_grab_get_focus ((MetaWaylandDragGrab *) grab) ||
+       meta_wayland_data_source_get_current_action (data_source) ==
+       WL_DATA_DEVICE_MANAGER_DND_ACTION_NONE))
+    meta_xwayland_end_dnd_grab (&seat->data_device);
 }
 
 static const MetaWaylandPointerGrabInterface drag_xgrab_interface = {
@@ -1537,6 +1559,7 @@ meta_xwayland_selection_handle_client_message (MetaWaylandCompositor *compositor
       else if (event->message_type == xdnd_atoms[ATOM_DND_DROP])
         {
           meta_wayland_surface_drag_dest_drop (drag_focus);
+          meta_xwayland_end_dnd_grab (&seat->data_device);
           return TRUE;
         }
     }
@@ -1596,7 +1619,6 @@ meta_xwayland_selection_handle_xfixes_selection_notify (MetaWaylandCompositor *c
   else if (selection->selection_atom == xdnd_atoms[ATOM_DND_SELECTION])
     {
       MetaWaylandDataDevice *data_device = &compositor->seat->data_device;
-      MetaXWaylandSelection *selection_data = compositor->xwayland_manager.selection_data;
       MetaWaylandSurface *focus;
 
       selection->owner = event->owner;
@@ -1617,8 +1639,7 @@ meta_xwayland_selection_handle_xfixes_selection_notify (MetaWaylandCompositor *c
         }
       else if (event->owner == None)
         {
-          meta_wayland_data_device_end_drag (data_device);
-          XUnmapWindow (xdisplay, selection_data->dnd.dnd_window);
+          meta_xwayland_end_dnd_grab (data_device);
         }
     }