[gtk+] wayland: Force the grab cursor while a grab is active

[Carlos Garnacho <carlosg src gnome org>]

commit ad0fc8ae7e24f47120520072cd6089a2ad8d3b5f
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Jan 8 21:45:03 2016 +0100

    wayland: Force the grab cursor while a grab is active
    
    When a cursor is specified in gdk_seat_grab(), the cursor is reverted as
    soon as the pointer enters or leaves another window.
    
    To avoid this issue, store the grab cursor separately, so we force-apply
    it in ::set_window_cursor(). Also, unset early the seat info from the
    window on gdk_seat_ungrab(), so the next time switch_to_pointer_grab()
    happens we end up picking the cursor set for the window underneath the
    pointer window.
    
    Based on a patch by Olivier Fourdan <ofourdan redhat com>.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=760213

 gdk/wayland/gdkdevice-wayland.c |   22 +++++++++++++++-------
 1 files changed, 15 insertions(+), 7 deletions(-)
---
diff --git a/gdk/wayland/gdkdevice-wayland.c b/gdk/wayland/gdkdevice-wayland.c
index 969ed96..144413a 100644
--- a/gdk/wayland/gdkdevice-wayland.c
+++ b/gdk/wayland/gdkdevice-wayland.c
@@ -116,6 +116,8 @@ struct _GdkWaylandSeat
   /* Some tracking on gesture events */
   guint gesture_n_fingers;
   gdouble gesture_scale;
+
+  GdkCursor *grab_cursor;
 };
 
 G_DEFINE_TYPE (GdkWaylandSeat, gdk_wayland_seat, GDK_TYPE_SEAT)
@@ -290,6 +292,9 @@ gdk_wayland_device_set_window_cursor (GdkDevice *device,
   if (device == wd->touch_master)
     return;
 
+  if (wd->pointer_grab_window)
+    cursor = wd->grab_cursor;
+
   /* Setting the cursor to NULL means that we should use
    * the default cursor
    */
@@ -2458,6 +2463,7 @@ gdk_wayland_seat_grab (GdkSeat                *seat,
                                     evtime,
                                     FALSE);
 
+      g_set_object (&wayland_seat->grab_cursor, cursor);
       g_set_object (&wayland_seat->cursor, cursor);
       gdk_wayland_device_update_window_cursor (wayland_seat);
     }
@@ -2514,6 +2520,15 @@ gdk_wayland_seat_ungrab (GdkSeat *seat)
   GdkDisplay *display = gdk_seat_get_display (seat);;
   GdkDeviceGrabInfo *grab;
 
+  g_clear_object (&wayland_seat->grab_cursor);
+
+  if (wayland_seat->pointer_grab_window)
+    {
+      _gdk_wayland_window_set_grab_seat (wayland_seat->pointer_grab_window,
+                                         NULL);
+      wayland_seat->pointer_grab_window = NULL;
+    }
+
   if (wayland_seat->master_pointer)
     {
       GdkWindow *focus, *prev_focus = NULL;
@@ -2551,13 +2566,6 @@ gdk_wayland_seat_ungrab (GdkSeat *seat)
       if (grab)
         grab->serial_end = grab->serial_start;
     }
-
-  if (wayland_seat->pointer_grab_window)
-    {
-      _gdk_wayland_window_set_grab_seat (wayland_seat->pointer_grab_window,
-                                         NULL);
-      wayland_seat->pointer_grab_window = NULL;
-    }
 }
 
 static GdkDevice *