Re: [PATCH v4 5/6] log: speed up --follow following renames for non-linear history

[Miklos Vajna <vmiklos@collabora.com>]

Hi Patrick,

On Fri, Nov 06, 2026 at 03:14:11PM +0100, Patrick Steinhardt <ps@pks.im> wrote:
> With unrelated histories this would return no bases at all, and hence
> we'd always return 0 in such a case. But 304812ed33d (log: improve
> --follow following renames for non-linear history, 2026-06-22)
> explicitly mentioned the use case of sub-tree merges of unrelated
> histories, so isn't this a regression?

You're right. The existing '--follow finds the pre-merge commit through
a subtree merge' test didn't catch this, because there no parent has the
path unchanged, so follow_needs_renames() is not called.

When there is no merge base, follow_needs_renames() now returns 1, so
renames are followed as before.

I've added a new '--follow finds the history of a copied file through a
subtree merge' test to 1/5 in v5 for such a case, and 5/5 now passes it.

Thanks,

Miklos