From 59acb38951381c196eb47e0a5d568a13feb442ad Mon Sep 17 00:00:00 2001
From: Daniel van Vugt <daniel.van.vugt@canonical.com>
Date: Thu, 20 Sep 2018 11:47:24 +0200
Subject: [PATCH] clutter: Avoid redundant margin changes

When profiling gnome-shell it was found that one of the main triggers
of `clutter_actor_queue_relayout` during animations was
`clutter_actor_set_margin_internal` continuously setting the same
zero margins. That's obviously pointless but also expensive since it
incurs full stage relayouts and reallocation. So just avoid redundant
margin changes.

Helps to further improve:
https://gitlab.gnome.org/GNOME/mutter/issues/233,
https://gitlab.gnome.org/GNOME/gnome-shell/issues/349
---
 clutter/clutter/clutter-actor.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index 3580ac1fd..f4f5db5c4 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -18434,6 +18434,10 @@ clutter_actor_set_margin_top (ClutterActor *self,
   g_return_if_fail (margin >= 0.f);
 
   info = _clutter_actor_get_layout_info_or_defaults (self);
+
+  if (info->margin.top == margin)
+    return;
+
   _clutter_actor_create_transition (self, obj_props[PROP_MARGIN_TOP],
                                     info->margin.top,
                                     margin);
@@ -18478,6 +18482,10 @@ clutter_actor_set_margin_bottom (ClutterActor *self,
   g_return_if_fail (margin >= 0.f);
 
   info = _clutter_actor_get_layout_info_or_defaults (self);
+
+  if (info->margin.bottom == margin)
+    return;
+
   _clutter_actor_create_transition (self, obj_props[PROP_MARGIN_BOTTOM],
                                     info->margin.bottom,
                                     margin);
@@ -18522,6 +18530,10 @@ clutter_actor_set_margin_left (ClutterActor *self,
   g_return_if_fail (margin >= 0.f);
 
   info = _clutter_actor_get_layout_info_or_defaults (self);
+
+  if (info->margin.left == margin)
+    return;
+
   _clutter_actor_create_transition (self, obj_props[PROP_MARGIN_LEFT],
                                     info->margin.left,
                                     margin);
@@ -18566,6 +18578,10 @@ clutter_actor_set_margin_right (ClutterActor *self,
   g_return_if_fail (margin >= 0.f);
 
   info = _clutter_actor_get_layout_info_or_defaults (self);
+
+  if (info->margin.right == margin)
+    return;
+
   _clutter_actor_create_transition (self, obj_props[PROP_MARGIN_RIGHT],
                                     info->margin.right,
                                     margin);