[mutter] clutter/cogl/stage: Don't leak FB damage region on redraw

[Jonas Ådahl <jadahl src gnome org>]

commit c4b28b0939d9591e51a6c909ac3462b6a85745ee
Author: Sebastian Keller <skeller gnome org>
Date:   Tue Feb 25 23:28:00 2020 +0100

    clutter/cogl/stage: Don't leak FB damage region on redraw
    
    offset_scale_and_clamp_region() creates a new region resulting in
    view_damage which at this point is the only thing left pointing to what
    originally was fb_damage getting overwritten and being leaked.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/1089

 clutter/clutter/cogl/clutter-stage-cogl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/clutter/clutter/cogl/clutter-stage-cogl.c b/clutter/clutter/cogl/clutter-stage-cogl.c
index 36d1531cc..ede58e6eb 100644
--- a/clutter/clutter/cogl/clutter-stage-cogl.c
+++ b/clutter/clutter/cogl/clutter-stage-cogl.c
@@ -743,8 +743,7 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
               /* Update the fb clip region with the extra damage. */
               cairo_region_union (fb_clip_region, fb_damage);
 
-              view_damage = g_steal_pointer (&fb_damage);
-              view_damage = offset_scale_and_clamp_region (view_damage,
+              view_damage = offset_scale_and_clamp_region (fb_damage,
                                                            0, 0,
                                                            1.0f / fb_scale);
               cairo_region_translate (view_damage, view_rect.x, view_rect.y);
@@ -755,6 +754,7 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
               cairo_region_union (redraw_clip, view_damage);
 
               cairo_region_destroy (view_damage);
+              cairo_region_destroy (fb_damage);
 
               CLUTTER_NOTE (CLIPPING, "Reusing back buffer(age=%d) - repairing region: num rects: %d\n",
                             age,