Re: "Medium" log format: change proposal for author != committer

From: Junio C Hamano <gitster@pobox.com>
Date: Sep 16, 2015, 01:52 UTC
Message-ID: <xmqq8u87t9jb.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <robbat2-20150915T214920-375711965Z@orbis-terrarum.net>

"Robin H. Johnson" <robbat2@gentoo.org> writes:

> Specifically, if the author is NOT the same as the committer, then
> display both in the header. Otherwise continue to display only the
> author.

I too found myself wanting to see both of the names sometimes, and the "fuller" format was added explicitly for that purpose.

Even though I agree "show only one, and both only when they are different" is a reasonable and possibly useful format, it is out of question to change what "--pretty=medium" does. It has been with us forever and people and their scripts do rely on it.

It would be good if we can say

    $ git log --pretty=robinsformat

but with a better name to show such an output.

Having said that, I'm moderately negative about adding it as yet another hard-coded format. We simply have too many, and we do not need one more. What we need instead is a flexible framework to let users get what they want.

I think what needs to happen is:

 * Enhance the "--pretty=format:" thing so that the current set of
   hardcoded --pretty=medium,short,... formats and your modified
   "medium" can be expressed as a custom format string.

 * Introduce a configuration mechanism to allow users to define new
   short-hand, e.g. if you have this in your $HOME/.gitconfig:

	[pretty "robin"]
        	format = "commit %H%nAuthor: %an <%ae>%n..."

   and run "git log --pretty=robin", it would behave as if you said
   "git log --pretty="format:commit %H%nAuthor: %an <%ae>%n...".

 * (optional) Replace the hardcoded implementations of pretty
   formats with short-hand names like "medium", "short", etc. with a
   built-in set of pretty.$name.format using the configuration
   mechanism.  But we need to make sure this does not hurt
   performance for common cases.