From bb8b92f93d6d7c028141c4876dd64dc3d52eb357 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Sun, 26 Jun 2011 12:00:08 +0200
Subject: [PATCH] Don't render shadows if there are no quads

---
 scene_opengl.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scene_opengl.cpp b/scene_opengl.cpp
index ca056680c8..5464e318b5 100644
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -665,6 +665,9 @@ void SceneOpenGL::Window::paintShadow(const QRegion &region, const WindowPaintDa
     quads.append(data.quads.select(WindowQuadShadowBottom));
     quads.append(data.quads.select(WindowQuadShadowBottomLeft));
     quads.append(data.quads.select(WindowQuadShadowLeft));
+    if (quads.isEmpty()) {
+        return;
+    }
     GLTexture *texture = static_cast<SceneOpenGLShadow*>(m_shadow)->shadowTexture();
     if (!texture) {
         return;