[mutter/gnome-3-28] wayland: Use cursor position in logical monitor

[Olivier Fourdan <ofourdan src gnome org>]

commit 7d52be02290bd92589fbea756ca3431af8e71a94
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Fri Mar 23 13:05:12 2018 +0100

    wayland: Use cursor position in logical monitor
    
    When using two monitors size by side with different scales, once the
    cursor moves from one output to another one, its size changes based on
    the scale of the given output.
    
    Changing the size of the cursor can cause the cursor area to change
    output again if the hotspot is not exactly at the top left corner of the
    area, causing the texture of the cursor to change, which will trigger
    another output change, so on and so forth causing continuous surface
    enter/leave event which flood the clients and eventually kill them.
    
    Change the logic to use only the actual cursor position to determine if
    its on the given logical monitor, so that it remains immune to scale
    changes induced by output scale differences.
    
    Closes: https://gitlab.gnome.org/GNOME/mutter/issues/83
    (cherry picked from commit 67917db45f96befb777e5f331a775ea3c2b53012)

 src/backends/meta-cursor-renderer.c            | 12 ++++++++++++
 src/backends/meta-cursor-renderer.h            |  1 +
 src/wayland/meta-wayland-surface-role-cursor.c |  9 +++++----
 3 files changed, 18 insertions(+), 4 deletions(-)
---
diff --git a/src/backends/meta-cursor-renderer.c b/src/backends/meta-cursor-renderer.c
index 0bdc59c15..f6470e66a 100644
--- a/src/backends/meta-cursor-renderer.c
+++ b/src/backends/meta-cursor-renderer.c
@@ -264,6 +264,18 @@ meta_cursor_renderer_set_position (MetaCursorRenderer *renderer,
   update_cursor (renderer, priv->displayed_cursor);
 }
 
+ClutterPoint
+meta_cursor_renderer_get_position (MetaCursorRenderer *renderer)
+{
+  MetaCursorRendererPrivate *priv =
+    meta_cursor_renderer_get_instance_private (renderer);
+
+  return (ClutterPoint) {
+    .x = priv->current_x,
+    .y = priv->current_y
+  };
+}
+
 MetaCursorSprite *
 meta_cursor_renderer_get_cursor (MetaCursorRenderer *renderer)
 {
diff --git a/src/backends/meta-cursor-renderer.h b/src/backends/meta-cursor-renderer.h
index 8ac0fe79b..1691f4471 100644
--- a/src/backends/meta-cursor-renderer.h
+++ b/src/backends/meta-cursor-renderer.h
@@ -62,6 +62,7 @@ void meta_cursor_renderer_set_cursor (MetaCursorRenderer *renderer,
 void meta_cursor_renderer_set_position (MetaCursorRenderer *renderer,
                                         float               x,
                                         float               y);
+ClutterPoint meta_cursor_renderer_get_position (MetaCursorRenderer *renderer);
 void meta_cursor_renderer_force_update (MetaCursorRenderer *renderer);
 
 MetaCursorSprite * meta_cursor_renderer_get_cursor (MetaCursorRenderer *renderer);
diff --git a/src/wayland/meta-wayland-surface-role-cursor.c b/src/wayland/meta-wayland-surface-role-cursor.c
index 1c8ba94e5..d118a8917 100644
--- a/src/wayland/meta-wayland-surface-role-cursor.c
+++ b/src/wayland/meta-wayland-surface-role-cursor.c
@@ -195,14 +195,15 @@ cursor_surface_role_is_on_logical_monitor (MetaWaylandSurfaceRole *role,
     META_WAYLAND_SURFACE_ROLE_CURSOR (surface->role);
   MetaWaylandSurfaceRoleCursorPrivate *priv =
     meta_wayland_surface_role_cursor_get_instance_private (cursor_role);
-  ClutterRect rect;
+  ClutterPoint point;
   ClutterRect logical_monitor_rect;
 
-  rect = meta_cursor_renderer_calculate_rect (priv->cursor_renderer,
-                                              priv->cursor_sprite);
   logical_monitor_rect =
     meta_rectangle_to_clutter_rect (&logical_monitor->rect);
-  return clutter_rect_intersection (&rect, &logical_monitor_rect, NULL);
+
+  point = meta_cursor_renderer_get_position (priv->cursor_renderer);
+
+  return clutter_rect_contains_point (&logical_monitor_rect, &point);
 }
 
 static void