[mutter] window-actor: Set viewport when blitting to screencast fb

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit a6f94696e2e8ade9e800f3b37092a5f40e22cf38
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Apr 3 17:12:58 2020 +0200

    window-actor: Set viewport when blitting to screencast fb
    
    This fixes an issue where a non-maximized screen casted window would be
    stretched to fill the whole screen cast stream, instead of just the crop
    that corresponds to the current window size.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1174

 src/compositor/meta-window-actor.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/compositor/meta-window-actor.c b/src/compositor/meta-window-actor.c
index 92355a918..31e0cb607 100644
--- a/src/compositor/meta-window-actor.c
+++ b/src/compositor/meta-window-actor.c
@@ -1300,6 +1300,7 @@ meta_window_actor_blit_to_framebuffer (MetaScreenCastWindow *screen_cast_window,
   cogl_color_init_from_4ub (&clear_color, 0, 0, 0, 0);
   cogl_framebuffer_clear (framebuffer, COGL_BUFFER_BIT_COLOR, &clear_color);
   cogl_framebuffer_orthographic (framebuffer, 0, 0, width, height, 0, 1.0);
+  cogl_framebuffer_set_viewport (framebuffer, 0, 0, width, height);
 
   meta_rectangle_scale_double (bounds, resource_scale,
                                META_ROUNDING_STRATEGY_GROW,