bug#4093: Overlay keymap and timers

[Stefan Monnier]

> Indeed, that function looks frightening.

I hoped you'd find it challenging.  Oh well!

> It's worth noting that XEmacs doesn't have this problem.

IIRC XEmacs's equivalent function restarts the whole work after every
event, so they look up the keymaps anew, and look them all up anew
(kind of like always jumping back to replay_sequence except that it
additionally recomputes the active keymaps).

> But the code differs drastically..

Yes, the algorithm is completely different.
I have a feeling it's related to the "frightening" above... nah!


        Stefan