Matt Armstrong <matt@rfc20.org> writes:

> I've got a patch to fix and will post it once I get a bug number.

...attached and also at the scratch/matta/for_stefan branch at
https://git.sr.ht/~matta/emacs (log link:
https://git.sr.ht/~matta/emacs/log/scratch/matta/for_stefan)

I am not happy with adding a new arg to 'overlays_in', but it appears we
really do have three distinct "modes" that can't be covered by simply
passing a half-open [beg,end) range.  It isn't an issue on master
because 'overlays_at' doesn't call 'overlays_in' there.  The fact that
the code wasn't shared probably allowed this subtle behavior difference
to slip through -- who knows if any callers rely on this.