[mutter] MetaRendererX11: Allocate offscreen framebuffers up front

[Jonas Ådahl <jadahl src gnome org>]

commit 9b4e8695f3ce068cdedb91cb48db3e70190a84f3
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Jul 25 16:51:14 2016 +0800

    MetaRendererX11: Allocate offscreen framebuffers up front
    
    Allocate the offscreen stage view framebuffers up front; otherwise they
    may get allocated after the viewport calculated by the stage is set,
    which would cause the viewport to be incorrect until recalculated.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=768976

 src/backends/x11/meta-renderer-x11.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/backends/x11/meta-renderer-x11.c b/src/backends/x11/meta-renderer-x11.c
index bd604bc..c0405be 100644
--- a/src/backends/x11/meta-renderer-x11.c
+++ b/src/backends/x11/meta-renderer-x11.c
@@ -78,6 +78,7 @@ meta_renderer_x11_create_view (MetaRenderer    *renderer,
   int width, height;
   CoglTexture2D *texture_2d;
   CoglOffscreen *offscreen;
+  GError *error = NULL;
 
   g_assert (meta_is_wayland_compositor ());
 
@@ -86,6 +87,9 @@ meta_renderer_x11_create_view (MetaRenderer    *renderer,
   texture_2d = cogl_texture_2d_new_with_size (cogl_context, width, height);
   offscreen = cogl_offscreen_new_with_texture (COGL_TEXTURE (texture_2d));
 
+  if (!cogl_framebuffer_allocate (COGL_FRAMEBUFFER (offscreen), &error))
+    meta_fatal ("Couldn't allocate framebuffer: %s", error->message);
+
   return g_object_new (META_TYPE_RENDERER_VIEW,
                        "layout", &monitor_info->rect,
                        "framebuffer", COGL_FRAMEBUFFER (offscreen),