On 2019-10-22 at 23:28:47, Prarit Bhargava wrote:
> In many projects the number of contributors is low enough that users know
> each other and the full email address doesn't need to be displayed.
> Displaying only the author's username saves a lot of columns on the screen.
> For example displaying "prarit" instead of "prarit@redhat.com" saves 11
> columns.
> 
> Add a "%aU"|"%au" option that outputs the author's email username.

I have no position on whether or not this is a useful change.  I don't
think I'll end up using it, but I can imagine cases where it is useful,
such as certain corporate environments.  It would be interesting to see
what others think.

> diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
> index b87e2e83e6d0..479a15a8ab12 100644
> --- a/Documentation/pretty-formats.txt
> +++ b/Documentation/pretty-formats.txt
> @@ -163,6 +163,9 @@ The placeholders are:
>  '%ae':: author email
>  '%aE':: author email (respecting .mailmap, see linkgit:git-shortlog[1]
>  	or linkgit:git-blame[1])
> +'%au':: author username
> +'%aU':: author username (respecting .mailmap, see linkgit:git-shortlog[1]
> +	or linkgit:git-blame[1])

I think we need to actually document what "username" means here.  I
expect you'll have people think that this magically means their
$HOSTING_PLATFORM username, which it is not.

> diff --git a/pretty.c b/pretty.c
> index b32f0369531c..2a5b93022050 100644
> --- a/pretty.c
> +++ b/pretty.c
> @@ -706,6 +706,11 @@ static size_t format_person_part(struct strbuf *sb, char part,
>  		strbuf_add(sb, mail, maillen);
>  		return placeholder_len;
>  	}
> +	if (part == 'u' || part == 'U') {	/* username */
> +		maillen = strstr(s.mail_begin, "@") - s.mail_begin;
> +		strbuf_add(sb, mail, maillen);
> +		return placeholder_len;
> +	}

This branch doesn't appear to do anything different for the mailmap and
non-mailmap cases.  Perhaps adding an additional test that demonstrates
the difference would be a good idea.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204