Re: [PATCH] xdiff: reduce indent heuristic overhead

> So if `N ≫ M`, there is necessarily a lot of repetition among the `N +
> M` lines that the hunk could possibly overlay. Specifically, it must
> consist of `floor((N + M)/M)` identical copies of the hunk, plus
> possibly a few leftover lines constituting the start of another repetition.
>
> Given this large amount of repetition, it seems to me that there is
> never a need to scan more than the bottom `M + 1` possible positions [1]
> plus the highest possible position [2] to be sure of finding the very
> best one. In the pathological case that you described above, where `M`
> is 1, only three positions have to be evaluated, not 100.