Re: [PATCH v2] trailer: allow spaces in tokens

From: Christian Couder <christian.couder@gmail.com>
To: Maxwell Bernstein <tekk.nolagi@gmail.com>
Cc: Junio C Hamano <gitster@pobox.com>,
	Max Bernstein via GitGitGadget <gitgitgadget@gmail.com>,
	git@vger.kernel.org,
	Max Bernstein <donotemailthisaddress@bernsteinbear.com>,
	Max Bernstein <max@bernsteinbear.com>,
	Jonathan Tan <jonathantanmy@google.com>
Subject: Re: [PATCH v2] trailer: allow spaces in tokens
Date: Thu, 18 Aug 2022 22:46:18 +0200	[thread overview]
Message-ID: <CAP8UFD1304rQh+9jMUkTmTvmNBxm6BNDt3=d07+C8iXSbJb2RA@mail.gmail.com> (raw)
In-Reply-To: <CM9DZ4Z18PY9.1T2O8U54X66FD@cedar>

On Thu, Aug 18, 2022 at 9:03 PM Maxwell Bernstein <tekk.nolagi@gmail.com> wrote:
>
> On Thu Aug 18, 2022 at 9:54 AM PDT, Junio C Hamano wrote:
> > So, the updated code mistook the body of the message that is not a
> > sign-off, because there is a colon on the line, the line does not
> > begin with the colon, and everything before the colon is an alnum or
> > a whitespace, so squashed the paragraph break before the real
> > trailer block and the last line of the body and made it a body-less
> > commit log message?
>
> I agree that it is not ideal, and I'm not sure how to fix it. This commit
> probably shouldn't go in as-is; I modified the test in order to demonstrate
> this problem.
>
> > This might be a good demonstration of why it is a mistaken design to
> > allow whitespaces, which may steer us toward fixing the documentation?
> >
> > I dunno.  What do others think?
>
> I think allowing whitespace is good at least for the Phabricator project, which
> despite being dead, has a number of existing users and existing commits. It
> unfortunately has a "Differential revision" trailer with whitespace.

I think allowing one white space before the separator is a good idea
for the following reasons.

First, if people use something like #, !, ~ or % as a separator, for
example in the case of a trailer like "Bug #43", it is very natural to
have a white space before the # separator.

Note that GitLab for example uses the ~N format, where N is a number,
for issues, !N for merge requests and %N for milestones. I think
Bugzilla and many other bug trackers use a #N format for bug numbers.

Also in some languages, like French, the typographical rules when
writing regular text is to have a space (technically it's supposed to
be a "non breaking space", see:
https://en.wikipedia.org/wiki/Non-breaking_space, but in practice
people use a regular space most of the time) before a colon. So it is
very natural for a number of people in the world to automatically add
a white space before a colon.

https://en.wikipedia.org/wiki/Colon_(punctuation)#Spacing says: "In
print, a thin space was traditionally placed before a colon and a
thick space after it. In modern English-language printing, no space is
placed before a colon and a single space is placed after it. In
French-language typing and printing, the traditional rules are
preserved. "

I think it would be very annoying for users to find out that a number
of otherwise proper trailers would not be taken into account only
because they have a white space before the colon. At least there
should be an option to allow that.