From 7d52be02290bd92589fbea756ca3431af8e71a94 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Fri, 23 Mar 2018 13:05:12 +0100
Subject: [PATCH] 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