Re: [PATCH 1/2] b4: introduce configuration for the Git project

From: Junio C Hamano <gitster@pobox.com>
Date: Jun 4, 2026, 01:11 UTC
Message-ID: <xmqqmrxbp0s6.fsf@gitster.g>
In-Reply-To: <aiAK9eLvew+mgWt+@szeder.dev>

SZEDER Gábor <szeder.dev@gmail.com> writes:

Show 10 quoted lines

> No, in Git shallow threading means that all patches are sent as a
> respose to the current cover letter, period.  It has nothing to do
> with whether the current cover letter is sent as a reply to the cover
> letter of the first or the previous version.
> ...
> Deep threading means that every mail is a reply to the previous one.
> Again, it has nothing to do with the relation of the current cover
> letter and the previous cover letters.
>
> Therefore, we do not recommend deep threading.

The above exactly matches my understanding of the current best practice. Inside an iteration of a series, we want a cover letter with everybody else responding to it. We do not have a word to describe how the latest iteration refers to its previous iteration via In-reply-to: or References: headers, but our preference is to make the cover letter of iteration N+1 to be a response to the cover letter of iteration N.

For a single-patch topic (without a cover letter) with multiple iterations, each iteration would be response to its previous iteration, which may make it look like "deep threading", but as you pointed out, the "deep threading" concept does not go across iterations.

Having said that, I've seen a cover letter of iteration N (for any value of N > 1) that respondes to the cover letter of the initial iteration. While it seems not to break "br" and the lore archive does not seem unhappy about it, I am not sure if tooling used by other people are also happy with it.

Thanks.