On Tue, Feb 15, 2022 at 4:51 PM Junio C Hamano [off-list ref] wrote:

In "name-rev [--tags] C", we look for a tag to use in describing the
given commit C as an ancestry path starting at the tag T (e.g. T~4,
T~2^2).  There can be multiple such tags (e.g. it is likely that a
commit that is v1.0~2 is also reachable from tag v2.0, even though
it would require more hops).  We try to and find a tag that gives
the "simplest" path.  For that purpose, it is no use to consider any
tag that is not a descendant of the given commit, because doing an
ancestry traversal starting from such a tag will never reach the
commit.  In a world where everybody's clock is in sync, if commit
was made at time X, any tag that was made before time X will not be
a descendant of the commit, so we do not add such a tag to the
candidate pool.

I think the idea of "cutoff" heuristic is exactly what generation
numbers can improve, in an imperfect world where there are imperfect
clocks.

Yep. I have a patch that will implement this behavior based on
Derrick's suggestion.

Thanks,
Jake