From: Phillip Wood <phillip.wood123@gmail•com>
To: Junio C Hamano <gitster@pobox•com>
Cc: git@vger•kernel.org, Jeff King <peff@peff•net>,
Matthias Beyer <mail@beyermatthias•de>,
Jacob Keller <jacob.keller@gmail•com>,
pyokagan@gmail•com
Subject: Re: [PATCH v2 2/2] templates: detect commit messages containing diffs
Date: Sat, 14 Feb 2026 14:36:39 +0000 [thread overview]
Message-ID: <20ed1f26-f60b-4e30-a0a5-8bd01dee19d1@gmail.com> (raw)
In-Reply-To: <xmqqfr74msm9.fsf@gitster.g>
On 13/02/2026 17:59, Junio C Hamano wrote:
> Phillip Wood <phillip.wood123@gmail•com> writes:
>
>> From: Phillip Wood <phillip.wood@dunelm•org.uk>
>>
>> If the body of a commit message contains a diff that is not indented
>> then "git am" will treat that diff as part of the patch rather than
>> as part of the commit message. This allows it to apply email messages
>> that were created by adding a commit message in front of a regular diff
>> without adding the "---" separator used by "git format-patch". This
>> often surprises users [1-4] so add a check to the sample "commit-msg"
>> hook to reject messages that would confuse "git am". Even if a project
>> does not use an email based workflow it is not uncommon for people
>> to generate patches from it and apply them with "git am". Therefore
>> it is still worth discouraging the creation of commit messages that
>> would not be applied correctly.
>>
>> A further source of confusion when applying patches with "git am" is
>> the "---" separator that is added by "git format patch". If a commit
>> message body contains that line then it will be truncated by "git am".
>> As this is often used by patch authors to add some commentary that
>> they do not want to end up in the commit message when the patch is
>> applied, the hook does not complain about the presence of "---" lines
>> in the message.
>
> "git format match" -> "git format-patch".
Thanks (I was confused for a minute because it says "format patch" above
not "format match" but you're pointing out that it should be hypenated)
>> The trailing ".*" when matching commented lines
>> ensures that if the comment string ends with a "$" it is not treated
>> as an anchor.
>
> I am not sure what this means. Wouldn't these three
>
> sed -e '/^#/d'
> sed -e '/^#.*/d'
> sed -e '/^#.*$/d'
>
> work exactly the same way?
They do, but if the comment string is '$' then these two
sed -e '/^$/d'
sed -e '/^$.*/d'
have different meanings
Thanks
Phillip
next prev parent reply other threads:[~2026-02-14 14:36 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-06 7:43 git-am applies commit message diffs Matthias Beyer
2026-02-06 8:04 ` Jacob Keller
2026-02-06 8:18 ` Matthias Beyer
2026-02-06 9:03 ` Jeff King
2026-02-07 14:57 ` [PATCH 0/3] commit-msg.sample: reject messages that would confuse "git am" Phillip Wood
2026-02-07 14:58 ` [PATCH 1/3] templates: add .gitattributes entry for sample hooks Phillip Wood
2026-02-07 14:58 ` [PATCH 2/3] templates: detect commit messages containing diffs Phillip Wood
2026-02-07 14:58 ` [PATCH 3/3] templates: detect messages that contain a separator line Phillip Wood
2026-02-07 21:27 ` Junio C Hamano
2026-02-07 21:38 ` Kristoffer Haugsbakk
2026-02-09 0:17 ` Junio C Hamano
2026-02-09 7:00 ` Jeff King
2026-02-09 10:42 ` Phillip Wood
2026-02-10 6:44 ` Jeff King
2026-02-09 6:57 ` [PATCH 0/3] commit-msg.sample: reject messages that would confuse "git am" Jeff King
2026-02-09 10:43 ` Phillip Wood
2026-02-09 11:07 ` Matthias Beyer
2026-02-10 6:46 ` Jeff King
2026-02-09 15:58 ` git-am applies commit message diffs Patrick Steinhardt
2026-02-10 2:16 ` Jacob Keller
2026-02-10 14:22 ` Patrick Steinhardt
2026-02-10 15:47 ` Junio C Hamano
2026-02-11 2:31 ` Jacob Keller
2026-02-11 2:34 ` Jacob Keller
2026-02-11 7:47 ` Jeff King
2026-02-11 15:23 ` Kristoffer Haugsbakk
2026-02-11 15:47 ` Junio C Hamano
2026-02-10 6:56 ` Jeff King
2026-02-13 14:34 ` [PATCH v2 0/2] commit-msg.sample: reject messages that would confuse "git am" Phillip Wood
2026-02-13 14:34 ` [PATCH v2 1/2] templates: add .gitattributes entry for sample hooks Phillip Wood
2026-02-13 14:34 ` [PATCH v2 2/2] templates: detect commit messages containing diffs Phillip Wood
2026-02-13 16:42 ` Kristoffer Haugsbakk
2026-02-13 18:08 ` Junio C Hamano
2026-02-14 14:46 ` Phillip Wood
2026-02-13 17:59 ` Junio C Hamano
2026-02-14 14:36 ` Phillip Wood [this message]
2026-02-14 15:42 ` Junio C Hamano
2026-02-13 17:41 ` [PATCH v2 0/2] commit-msg.sample: reject messages that would confuse "git am" Junio C Hamano
2026-02-06 8:59 ` git-am applies commit message diffs Florian Weimer
2026-02-06 9:24 ` Jeff King
2026-02-06 9:48 ` Florian Weimer
2026-02-06 10:08 ` Jeff King
2026-02-06 8:43 ` Kristoffer Haugsbakk
2026-02-06 17:45 ` Jakob Haufe
2026-02-07 10:08 ` Kristoffer Haugsbakk
2026-02-07 21:44 ` Kristoffer Haugsbakk
2026-02-08 0:11 ` [PATCH] doc: add caveat about roundtripping format-patch kristofferhaugsbakk
2026-02-08 1:39 ` Junio C Hamano
2026-02-08 17:18 ` Kristoffer Haugsbakk
2026-02-09 16:42 ` Phillip Wood
2026-02-09 17:59 ` Kristoffer Haugsbakk
2026-02-10 10:57 ` Phillip Wood
2026-02-10 16:00 ` Kristoffer Haugsbakk
2026-02-09 22:37 ` [PATCH v2] " kristofferhaugsbakk
2026-02-09 22:59 ` Junio C Hamano
2026-02-09 23:11 ` Kristoffer Haugsbakk
2026-02-10 11:02 ` Phillip Wood
2026-02-10 18:20 ` Kristoffer Haugsbakk
2026-02-12 22:28 ` [PATCH v3] doc: add caveat about round-tripping format-patch kristofferhaugsbakk
2026-02-12 23:19 ` Junio C Hamano
2026-02-13 14:41 ` Phillip Wood
2026-02-13 14:43 ` Kristoffer Haugsbakk
2026-02-13 18:02 ` Junio C Hamano
2026-02-10 0:53 ` [PATCH] doc: add caveat about roundtripping format-patch Christoph Anton Mitterer
2026-02-10 16:00 ` Kristoffer Haugsbakk
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