Comment 4 for bug 905456

(In reply to comment #1)
> There is a bug in the 32-bit mesa build, when asm is enabled -
> glXGetProcAddress returns non-NULL for any string starting with "gl".
>
> In this case the app calls glXGetProcAddress with the incorrect function name,
> e.g. "glCreateShaderObject", mesa incorrectly returns non-NULL, the app calls
> it.
Sounds like a bug in the application to me. From the GLX 1.4 spec (though that's certainly not new in 1.4):

"A non-NULL return value for glXGetProcAddress does not guarantee that an extension function is actually supported at runtime. The client must also query glGetString() or glXQueryExtensionsString to determine if an extension is supported by a particular context."