RFC: Use libxkbcommon in Xorg

[Jon TURNEY]

On 22/10/2010 03:26, Kristian Høgsberg wrote:
> Now, it's all looking pretty promising, but there are a few open
> issues I'd like to throw to the list.  First of all, there's the issue
> of how this intersects/dovetails/conflicts with xkb2.  Part of the
> original plan for libxkbcommon as part of xkb2 was to also increase
> the size of certain datatypes in xkb: bump keycodes and virtual mods
> to 32 bits.  We can't do that with the existing xkb protocol and will
> require xkb2 protocol with new requests to serialize the xkb
> descriptions and we need to rethink some of the ways we represent
> certain state (per keycode repeat info makes a pretty big bit vector
> for 32 bit keycodes).  I don't think that's realistic for a 1.10
> xserver release, and I've changed the libxkbcommon structs back to be
> compatible with the current xkb protocol and implementation.  We can
> extend libxkbcommon to support bigger keycodes and vmods in a later
> release.  It's not going to be as pretty as if we did it all in the
> first release, but I think there's too much potential here to block it
> on xkb2.

I can't really speak to the technical issues, but fwiw, I'd also rather not 
see this get blocked on xkb2, as forking xkbcomp on startup is particularly 
slow on cygwin due to the expensive fork emulation, and also unfortunately 
rather brittle.

A couple of minor build fix patches to follow.