[mutter/wip/carlosg/fix-second-monitor-invalidations] clutter/cogl: Fix invalidation on non-primary monitors with no buffer age

[Carlos Garnacho <carlosg src gnome org>]

commit e0da39bb81335003c9dff35037403f2a72f6e583
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue Oct 29 15:54:36 2019 +0100

    clutter/cogl: Fix invalidation on non-primary monitors with no buffer age
    
    We passed the view rectangle, we however want a fb-scaled rectangle starting
    at 0,0. Fixes invalidation on other than the primary monitor when those
    paths are hit.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/898

 clutter/clutter/cogl/clutter-stage-cogl.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/clutter/clutter/cogl/clutter-stage-cogl.c b/clutter/clutter/cogl/clutter-stage-cogl.c
index 751f26da3..78a7d8ffc 100644
--- a/clutter/clutter/cogl/clutter-stage-cogl.c
+++ b/clutter/clutter/cogl/clutter-stage-cogl.c
@@ -943,9 +943,16 @@ clutter_stage_cogl_redraw_view (ClutterStageWindow *stage_window,
         }
       else
         {
+          cairo_rectangle_int_t clip;
           cairo_region_t *view_region;
 
-          view_region = cairo_region_create_rectangle (&view_rect);
+          clip = (cairo_rectangle_int_t) {
+            .x = 0,
+            .y = 0,
+            .width = ceilf (view_rect.width * fb_scale),
+            .height = ceilf (view_rect.height * fb_scale)
+          };
+          view_region = cairo_region_create_rectangle (&clip);
           paint_stage (stage_cogl, view, view_region);
           cairo_region_destroy (view_region);
         }