[Xcb] RFC: The need to break the API. (Im)Possible?

[Daniel Martin]

Dear list readers,

we've had a few places in proto we couldn't fix correctly as a correct
fix would break the API of libxcb, recently. Then I see a lot of places
in proto that should be changed to represent the actual protocol more
precisely. To mention a few:
- replace valueparams with switch/bitcases
- replace unions with switch/cases (yes, they aren't supported yet)
- or just the typo "permament":
    http://cgit.freedesktop.org/xcb/proto/tree/src/xkb.xml#n471

I would like to contribute such changes to proto, but they all break the
API of libxcb. So, does anyone has an idea how we can handle such
changes?


Cheers,
    Daniel

PS: Replacing unions with switch/cases is one requirement if anyone ever
    wants to generate the byte-swapping code for the server. ;)