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

Hi,

I want to propose a change to the 'medium' log output format, to improve readability.

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

This would aid quick review of changes in git-log & git-show output.

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

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.

On Tue, Sep 15, 2015 at 6:52 PM, Junio C Hamano <gitster@pobox.com> wrote:

Afiak there is already support for this.. from "git help config":

pretty.<name> Alias for a --pretty= format string, as specified in git-log(1). Any aliases defined here can be used just as the built-in pretty formats could. For example, running git config pretty.changelog "format:* %H %s" would cause the invocation git log --pretty=changelog to be equivalent to running git log "--pretty=format:* %H %s". Note that an alias with the same name as a built-in format will be silently ignored.

So this should already be supported... but to support "robinsformat" we'd need to be able to "show committer only if different from author"... Not sure how that would work.

This part obviously hasn't been done, I don't know if any particular format is not expressable today by the pretty syntax or not..

But at least configuration does work. I use it as part of displaying the

Fixes: <sha1> ("name")

used by the upstream kernel for marking bug fixes of known commits.

Thus the only real thing would be implementing a % modifier which allows showing commiter if it's not the same as author. (or vise versa) Ideally we could take work from the ref-filter library and the proposed "%if" stuff but I don't tihnk this was actually implemented yet, and I don't know if that would even work in the pretty modifiers.

Regards, Jake

Jacob Keller <jacob.keller@gmail.com> writes:

Yup. But before the first bullet item is done, it cannot be used to replace the built-in hardcoded formats with a built-in set of default configurations.

One that we know we cannot is the nice conditional one Robin wants. I do think it is a reasonable thing to have.