Re: [PATCH 0/3] making --first-parent imply -m

From: Jeff King <peff@peff.net>
Date: Jul 28, 2020, 16:53 UTC
Message-ID: <20200728165337.GB2650574@coredump.intra.peff.net>
In-Reply-To: <xmqqeeovegbv.fsf@gitster.c.googlers.com>

On Tue, Jul 28, 2020 at 09:48:20AM -0700, Junio C Hamano wrote:

Show 15 quoted lines

> Jeff King <peff@peff.net> writes:
> 
> > For some projects, it's useful to walk the first parent history, looking
> > at each merge commit as a normal commit introducing all of the changes
> > no its side branch. E.g.:
> >
> >   git log --first-parent -m -Sfoo -p
> >
> > might show you the topic or pull request that introduced code "foo". But
> > I quite often forget to add "-m", and get confused that it doesn't
> > return any results.
> 
> Yes.  I agree that --first-parent should imply -m when combined with
> diff options like -p, --raw, etc.  I am not sure if -m should kick
> in without any diff options, though.  Doesn't it have side effects?

I couldn't find any. It impacts log_tree_diff() if we see a commit with two parents, but --first-parent will already override that.

I poked around in the code and couldn't find any other cases that would be impacted, nor do any tests fail. Definitely if you can find a case where it matters outside of the diff, I'd be interested to see it. :)

-Peff