From 65230bfd7fe861de4f2eaa58d058722f7ace8d99 Mon Sep 17 00:00:00 2001
From: "Owen W. Taylor" <otaylor@fishsoup.net>
Date: Mon, 16 Jan 2012 14:43:35 -0500
Subject: [PATCH] st-theme-node-drawing: clear border buffer before drawing on
 it

A new texture has undefined contents - when we're creating a shadow,
we need to clear the contents of the texture before drawing the border
and background into it.

https://bugzilla.gnome.org/show_bug.cgi?id=668048
---
 src/st/st-theme-node-drawing.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/st/st-theme-node-drawing.c b/src/st/st-theme-node-drawing.c
index 440ca138a..b83481192 100644
--- a/src/st/st-theme-node-drawing.c
+++ b/src/st/st-theme-node-drawing.c
@@ -1427,9 +1427,14 @@ st_theme_node_render_resources (StThemeNode   *node,
           if (offscreen != COGL_INVALID_HANDLE)
             {
               ClutterActorBox box = { 0, 0, width, height };
+              CoglColor clear_color;
 
               cogl_push_framebuffer (offscreen);
               cogl_ortho (0, width, height, 0, 0, 1.0);
+
+              cogl_color_set_from_4ub (&clear_color, 0, 0, 0, 0);
+              cogl_clear (&clear_color, COGL_BUFFER_BIT_COLOR);
+
               st_theme_node_paint_borders (node, &box, 0xFF);
               cogl_pop_framebuffer ();
               cogl_handle_unref (offscreen);