Re: [PATCH v3 7/7] documentation: format-patch: clarify requirements for patch-ids to match

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 17, 2022, 15:18 UTC
Message-ID: <xmqqo7ua1nrz.fsf@gitster.g>
In-Reply-To: <69440797f302729d59f19c0994916e193c9dbf58.1665737804.git.gitgitgadget@gmail.com>

"Jerry Zhang via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 7 quoted lines

>  The 'base commit' is shown as "base-commit: " followed by the 40-hex of
>  the commit object name.  A 'prerequisite patch' is shown as
>  "prerequisite-patch-id: " followed by the 40-hex 'patch id', which can
> -be obtained by passing the patch through the `git patch-id --stable`
> -command.
> +be obtained by passing the patch (generated with -U3 --full-index) through
> +the `git patch-id --stable` command.

This is not incorrect per-se, but I wonder how much it would help or mislead people in practice.

I understand that the update means well to help those who complain "'patch-id' produces wrong result when I feed the output of 'git diff -U1'" by making them suspect that their -U1 may be the culprit. But the new description does not cover everything that can affect the resulting patch ID (the choice of --diff-algorithm affects how common lines are matched up between the preimage and the postimage, for example).

So, I dunno.