[mutter] cogl: Flush journal before blitting

[Jonas Ådahl <jadahl src gnome org>]

commit 0cdf13ac12c570d38737fddb68946157c0b7a4d2
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Tue Oct 1 15:54:47 2019 +0200

    cogl: Flush journal before blitting
    
    Make sure to submit all pending primitives before blitting, otherwise
    rendering from the shell may be incomplete leaving partial drawing of
    the shell widgets.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/820

 cogl/cogl/cogl-framebuffer.c | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/cogl/cogl/cogl-framebuffer.c b/cogl/cogl/cogl-framebuffer.c
index 527fd81ea..e3e112f8c 100644
--- a/cogl/cogl/cogl-framebuffer.c
+++ b/cogl/cogl/cogl-framebuffer.c
@@ -1374,6 +1374,11 @@ cogl_blit_framebuffer (CoglFramebuffer *src,
       return FALSE;
     }
 
+  /* Make sure any batched primitives get submitted to the driver
+   * before blitting
+   */
+  _cogl_framebuffer_flush_journal (src);
+
   /* Make sure the current framebuffers are bound. We explicitly avoid
      flushing the clip state so we can bind our own empty state */
   _cogl_framebuffer_flush_state (dest,