[Xcb] Whatever happened to the XCloseDisplay() hooks?

[Jamey Sharp]

I agree with the general sentiments of Bart's note here: libxcb
currently provides no callbacks under any circumstances, and I want to
see a very convincing argument before changing that. That isn't a
"no", just a request for more discussion.

Of course as Julien pointed out after I started composing this, we
can't have every library providing its own disconnect wrapper, so
Bart, I think your proposal can't work.

I'd argue in a different direction: higher layers should manage
caches. The cairo XCB surface constructors could take a
cairo-xcb-connection object instead of the xcb_connection_t. That
object would be constructed from an xcb_connection_t and contain any
caches you want. The caller can decide when to allocate and free that
association.

What nightmare arises if you take that approach?

Jamey