[mutter] constraints: Only get parent rect once when placement rule constraining

[Florian Müllner <fmuellner src gnome org>]

commit 86b52477702ae03bb8096d8329eac8f1c841fc68
Author: Jonas Ådahl <jadahl gmail com>
Date:   Wed Oct 24 11:39:09 2018 +0200

    constraints: Only get parent rect once when placement rule constraining
    
    We got it in a switch case, then again when finalizing. Only get it once
    instead.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/496

 src/core/constraints.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)
---
diff --git a/src/core/constraints.c b/src/core/constraints.c
index cf039a580..d468c2d92 100644
--- a/src/core/constraints.c
+++ b/src/core/constraints.c
@@ -821,13 +821,14 @@ constrain_custom_rule (MetaWindow         *window,
 
   adjusted_unconstrained = info->current;
 
+  parent = meta_window_get_transient_for (window);
+  meta_window_get_frame_rect (parent, &parent_rect);
+
   switch (window->placement_state)
     {
     case META_PLACEMENT_STATE_UNCONSTRAINED:
       break;
     case META_PLACEMENT_STATE_CONSTRAINED:
-      parent = meta_window_get_transient_for (window);
-      meta_window_get_frame_rect (parent, &parent_rect);
       adjusted_unconstrained.x =
         parent_rect.x + window->constrained_placement_rule_offset_x;
       adjusted_unconstrained.y =
@@ -948,8 +949,6 @@ constrain_custom_rule (MetaWindow         *window,
 done:
   window->placement_state = META_PLACEMENT_STATE_CONSTRAINED;
 
-  parent = meta_window_get_transient_for (window);
-  meta_window_get_frame_rect (parent, &parent_rect);
   window->constrained_placement_rule_offset_x = info->current.x - parent_rect.x;
   window->constrained_placement_rule_offset_y = info->current.y - parent_rect.y;