bug#58158: 29.0.50; [overlay] Interval tree iteration considered harmful

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

> Can you propose a fix?

Other than completely rewrite at least this part, no.

> I guess the begin_iteration/end_iteration dance is because the tree
> could be in inconsistent state in-between?  If so, what would it take
> to avoid the inconsistency?

I find it very hard to tell why this is done the way it is.  If someone
knowing the code can think of a reason, please speak up.