Hide some GLX extensions by default to avoid guest call missing GLX API. It's
hacky to implement these APIs, so hide these extensions as fix.

Upstream-Status: Pending

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>

Index: git/opengl_client.c
===================================================================
--- git.orig/opengl_client.c	2012-03-16 18:22:27.000000000 +0800
+++ git/opengl_client.c	2012-03-16 18:52:06.000000000 +0800
@@ -105,6 +105,12 @@
   "NO_MOVE",                 /* default : set if TCP/IP communication */
 };
 
+/* Hiding some GLX extensions from guest */
+static const char* hiding_extensions =
+  "GLX_MESA_copy_sub_buffer,\
+   GLX_MESA_multithread_makecurrent,\
+   GLX_MESA_swap_control,\
+  ";
 
 #ifdef WIN32
 
@@ -3516,7 +3522,8 @@
 static void removeUnwantedExtensions(char* ret)
 {
   char* toBeRemoved = getenv("GL_REMOVE_EXTENSIONS");
-  if (toBeRemoved == NULL) return;
+  if (toBeRemoved == NULL)
+    toBeRemoved = hiding_extensions;
   toBeRemoved = strdup(toBeRemoved);
   char* iterToBeRemoved = toBeRemoved;
   while(*iterToBeRemoved)