Matt Tucker <tuck(a)whistlingfish.net&gt; writes: Excellent. After that, I think your patch should just go in. I don't think we even need the configure-time switch, heavens know we have too many of these already. We can keep the Lisp variable for font-lock, though, to bring us through the debugging stage. That's one of the rare good things about "merges" with FSF Emacs: the code gets better debugging because it goes through at least another pair of careful eyes. I agree. Yes. Also, you could optimize things by caching these lists in internal hash tables, at the time when they're added to the extent (you have control over the extents code, so you can do that). I would say the latter. That would be cool. You might want to look if adding the overlapping support would break compatibility with the FSF for the common cases. And there's the speed issue again. XEmacs is very complex. We should always be extremely careful with adding this kind of stuff.