return null if no context

src/mesa/main/getstring.c

@@ -1,8 +1,8 @@
 /*
  * Mesa 3-D graphics library
- * Version:  6.3
+ * Version:  6.5.2
  *
- * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -60,6 +60,9 @@ _mesa_GetString( GLenum name )
    static const char *sl_version_110 = "1.10 Mesa " MESA_VERSION_STRING;
 #endif
 
+   if (!ctx)
+      return NULL;
+
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, NULL);
 
    /* this is a required driver function */