From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 02 Aug 2024 17:30:12 GMT
Subject: Re: [PATCH 0/3] git for-each-ref: is-base atom and base branches
Message-ID: <xmqqo76ade8r.fsf@gitster.g>
In-Reply-To: <xmqqzfpudful.fsf@gitster.g>

Junio C Hamano <gitster@pobox.com> writes:

>> +is-base:<committish>::
>> +	In at most one row, `(<committish>)` will appear to indicate the ref
>> +	that minimizes the number of commits in the first-parent history of
>> +	`<committish>` and not in the first-parent history of the ref.

This was a bit too dense for me to grok.  So if I have a <commit>
that is at the tip of a branch B forked from 'master', and then
'master' advanced by a lot since the branch forked, the number this
is minimizing for 'master' is the commits on the branch B, but when
showing 'maint', then even though the branch B may have the tip of
'maint' as an ancestor, the number for 'maint' would be a lot more
than the number for 'master'.  If there were another branch C that
was forked from 'master' and shared some (or all) commits that are
near the tip of branch B, e.g.

    ---o---o---o---o---o---o---o---o---o 'master'
            \
             o---o---o---o 'C'
                      \    
                       o---o---o---o 'B'

then the number may be even smaller for branch 'C' than 'master'.

And for at most one ref, %(is-base:<commit>) becomes "(<commit>)";
for all other refs, it becomes an empty string.

OK.

> OK.  Knowing what definition you used is crucial when reading the
> implementation, as we cannot tell what you wanted to implement
> without it ;-)
>
> Thanks.