From cd585972aeb16ed09a0812ffa35aa438f436bc00 Mon Sep 17 00:00:00 2001
From: Philipp Knechtges <philipp-dev@knechtges.com>
Date: Thu, 1 Dec 2011 22:41:10 +0100
Subject: [PATCH] kwin: avoid SEGFAULT in case of egl_glx

The mesa egl_glx egl driver only provides indirect rendering which is
insufficient for GLES2.
---
 compositingprefs.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/compositingprefs.cpp b/compositingprefs.cpp
index e5ec647490..4a7f9b89c7 100644
--- a/compositingprefs.cpp
+++ b/compositingprefs.cpp
@@ -310,6 +310,12 @@ bool CompositingPrefs::initEGLContext()
     EGLConfig configs[1024];
     eglChooseConfig(mEGLDisplay, config_attribs, configs, 1024, &count);
 
+    if (count == 0) {
+        // egl_glx only supports indirect rendering, which itself does not allow GLES2
+        kWarning(1212) << "You might be using mesa egl_glx, which is not supported!";
+        return false;
+    }
+
     EGLint visualId = XVisualIDFromVisual((Visual*)QX11Info::appVisual());
 
     EGLConfig config = configs[0];