mesa: queries of non-existent FBO attachments should return INVALID_OPERATION

OpenGL 4.0 Compatibility, page 449:

If the value of FRAMEBUFFER_ATTACHMENT_OBJECT_TYPE is NONE, no
framebuffer is bound to target. In this case querying pname FRAMEBUFFER_-
ATTACHMENT_OBJECT_NAME will return zero, and all other queries will generate
an INVALID_OPERATION error.

Reviewed-by: Chad Versace <chad@chad-versace.us>
1 file changed