Subject: Re: Is there a way to get the "format-patch" formatted file name?

From: Junio C Hamano <[email-masked]>
Date: Fri, 01 Sep 2023 08:53:14 -0700

Oswald Buddenhagen <[email-masked]> writes:

> but i wouldn't be opposed to for example git-mailinfo learning to
> understand the --pretty argument, if the implementation doesn't turn
> out to be completely out of proportion.

Excellent suggestion.  I agree that 'mailinfo' would be the closest
place we have for such a new feature.  It's "info" output (i.e. what
comes out to the standard output of the command) is designed to be
extensible, and I vaguely recall that we indeed have added new
field(s) during its lifetime with existing users already.

We can just invent a new label (e.g. "Filesystem-safe-subject:"),
pass the subject string to pretty.c:format_sanitized_subject() and
emit the result next to the existing "Subject:" with that label, and
we can even do so unconditionally without breaking anybody.

Having it in 'mailinfo' may still not be a good solution to the
issue, given that Vit says

>> But I typically don't have a Git.

though.

On a related not-so-distant tangent, we probably should redo the
support for --message-id to emit it as an extra entry to the "info"
output, instead of contaminating the "message" output.  The option
was added only to support "git am --message-id", and as long as the
calling "am" and "mailinfo" are updated in sync to use the "info"
output to carry the Message-Id: information, we should be able to do
such a clean-up without changing the externally visible behaviour.