Re: [BUG] Documentation: git log: --exit-code undocumented?

[Sergey Organov <sorganov@gmail.com>]

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

> David Kastrup <dak@gnu.org> writes:
>
>> I disagree that --exit-code does nothing: it indicates whether the
>> listed log is empty.  So for example
>>
>> git log -1 --exit-code a..b > /dev/null
>>
>> can be used to figure out whether "a" is a proper ancestor of "b" or
>> not.
>
> Hmph.
>
>     $ git log --exit-code master..maint >/dev/null; echo $?
>     0
>     $ git log --exit-code maint..master >/dev/null; echo $?
>     1
>
> That is a strange way to use --exit-code.

What's the best way then to tell if "a" is an ancestor of "b"?

-- 
Sergey.