Re: [PATCH] send-email: restore --in-reply-to superseding behavior

From: Junio C Hamano <gitster@pobox.com>
To: Rafael Aquini <aquini@redhat.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH] send-email: restore --in-reply-to superseding behavior
Date: Wed, 24 Jun 2020 14:33:14 -0700	[thread overview]
Message-ID: <xmqqo8p85eud.fsf@gitster.c.googlers.com> (raw)
In-Reply-To: <20200624195520.2062298-1-aquini@redhat.com> (Rafael Aquini's message of "Wed, 24 Jun 2020 15:55:20 -0400")

Rafael Aquini <aquini@redhat.com> writes:

> git send-email --in-reply-to= fails to override the email headers,
> if they're present in the output of format-patch, which breakes the

Will do s/breakes/breaks/ while applying.

It makes me wonder, however, why it is a good idea to have the I-R-T
in the format patch output in the first place.

>  			elsif (/^In-Reply-To: (.*)/i) {
> -				$in_reply_to = $1;
> +				if (!$initial_in_reply_to) {
> +					$in_reply_to = $1;
> +				}

I can see how this would work the way it should for the first
message we send out, so it would work well for a single patch.

But what does this change do to the chaining (either making [PATCH
1/N] thru [PATCH N/N] as responses to the cover letter [PATCH 0/N],
or making [PATCH n+1/N] as response to [PATCH n/N] for 1 <= n < N)
of multiple messages?

When you prepare a series whose 1..N/N are all pointing at 0/N with
the already prepared In-Reply-To (so you have N+1 files to send
out), wouldn't you want to make 0/N a reply to a particular message
you specify on the command line, while keeping the relationship
among your messages intact?  Doesn't having $initial_in_reply_to
(i.e. command line override) help above code break the chaning?

>  			}
>  			elsif (/^References: (.*)/i) {
> -				$references = $1;
> +				if (!$initial_in_reply_to) {
> +					$references = $1;
> +				}
>  			}
>  			elsif (!/^Date:\s/i && /^[-A-Za-z]+:\s+\S/) {
>  				push @xh, $_;