clutter/stage-cogl: Ensure queued_redraw_clip is not empty

When using `CLUTTER_PAINT=damage-region` highlighting was conspicuously
absent during fullscreen animations like entering or leaving the
overview. That was because `queued_redraw_clip` was empty, because it
had been initialized from `redraw_clip == NULL` (full stage redraw).

Now we paint the damage region as the full view (which it is) instead
of nothing at all.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1890>

1 files changed, 3 insertions, 3 deletions

diff --git a/clutter/clutter/cogl/clutter-stage-cogl.c b/clutter/clutter/cogl/clutter-stage-cogl.c
index 5e81899b0..2fe6bd10e 100644
--- a/clutter/clutter/cogl/clutter-stage-cogl.c
+++ b/clutter/clutter/cogl/clutter-stage-cogl.c
@@ -541,12 +541,12 @@ clutter_stage_cogl_redraw_view_primary (ClutterStageCogl *stage_cogl,
       };
       fb_clip_region = cairo_region_create_rectangle (&fb_rect);
 
+      g_clear_pointer (&redraw_clip, cairo_region_destroy);
+      redraw_clip = cairo_region_create_rectangle (&view_rect);
+
       if (G_UNLIKELY (clutter_paint_debug_flags &
                       CLUTTER_DEBUG_PAINT_DAMAGE_REGION))
         queued_redraw_clip = cairo_region_reference (redraw_clip);
-
-      g_clear_pointer (&redraw_clip, cairo_region_destroy);
-      redraw_clip = cairo_region_create_rectangle (&view_rect);
     }
 
   g_return_if_fail (!cairo_region_is_empty (fb_clip_region));