A question about struct coding_system

[Dmitry Antipov]

At a first glance, struct coding_system should be a vector-like
object with src_object and dst_object at the beginning. But it
isn't, and it looks like that src_object and dst_object are never
marked directly. Thus, it should be guaranteed that, for any
coding_system, objects referenced by src_object and dst_object
are always reachable from another live objects. But I can't
find any code that takes care about this, so I don't understand
why and how it works at all :-(.

Dmitry