From: "Jakub Narębski" <jnareb@gmail.com>
To: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 3/3] gitweb: Link to "git describe"'d commits in log messages
Date: Wed, 21 Sep 2016 19:09:27 +0200 [thread overview]
Message-ID: <fadd75f3-3737-1eaf-30f3-46a2ef132b27@gmail.com> (raw)
In-Reply-To: <20160921114428.28664-3-avarab@gmail.com>
W dniu 21.09.2016 o 13:44, Ævar Arnfjörð Bjarmason napisał:
> Change the log formatting function to know about "git describe" output
> like v2.8.0-4-g867ad08 in addition to just plain 867ad08.
All right, that is a good plan.
>
> This also fixes a micro-regression in my change of the minimum SHA1
> length from 8 to 7, which is that dated tags like
> hadoop-20160921-113441-20-g094fb7d would start thinking the "20160921"
> part was a commit.
Actually 20160921 is 8 characters, so assuming that '-' is treated
as word boundary by Perl, it is not a regression; this false positive
was there. The new feature would help, instead of linking false match
it links whole git-describe output.
So this paragraph needs to be changed wrt. the above.
Note that there are quite a bit of shortened SHA-1 that are composed
entirely from digits, without a-f characters.
>
> There are still many valid refnames that we don't link to
> e.g. v2.10.0-rc1~2^2~1 is also a valid way to refer to
> v2.8.0-4-g867ad08, but I'm not supporting that with this commit,
> similarly it's trivially possible to create some refnames like
> "æ/var-gf6727b0" or whatever which won't be picked up by this regex.
Hopefully hierarchical tags are rare. We need to reduce false
positives.
>
> There's surely room for improvement here, but I just wanted to address
> the very common case of sticking "git describe" output into commit
> messages without trying to link to all possible refnames, that's going
> to be a rather futile exercise given that this is free text, and it
> would be prohibitively expensive to look up whether the references in
> question exist in our repository.
Note that we do not ask Git at the time of displaying commit message
if the link is valid for performance reasons; we link it, and the link
may be invalid if it was a false positive.
Note that recommended way to refer to other commit in commit mesages
is (see Documentation/SubmittingPatches):
If you want to reference a previous commit in the history of a stable
branch, use the format "abbreviated sha1 (subject, date)",
with the subject enclosed in a pair of double-quotes, like this:
Commit f86a374 ("pack-bitmap.c: fix a memleak", 2015-03-30)
noticed that ...
Hmmm... this makes previous commit even more important.
> ---
> gitweb/gitweb.perl | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 101dbc0..3a52bc7 100755
> --- a/gitweb/gitweb.perl
> +++ b/gitweb/gitweb.perl
> @@ -2036,10 +2036,24 @@ sub format_log_line_html {
> my $line = shift;
>
> $line = esc_html($line, -nbsp=>1);
> - $line =~ s{\b([0-9a-fA-F]{7,40})\b}{
> + $line =~ s{
> + \b
> + (
> + # The output of "git describe", e.g. v2.10.0-297-gf6727b0
> + # or hadoop-20160921-113441-20-g094fb7d
All right, for more complex regular expressions using in-line comments
(extended regexp in Perl) is a good idea.
> + (?<!-) # see strbuf_check_tag_ref(). Tags can't start with -
> + [A-Za-z0-9.-]+
> + (?!\.) # refs can't end with ".", see check_refname_format()
If we can assume that tag name is at least two characters (instead of
at least one character), we could get rid of those extended regexp
lookaround assertions:
(?<!pattern) - zero-width negative lookbehind assertion
(?!pattern) - zero-width negative lookahead assertion
That is:
+ [A-Za-z0-9.] # see strbuf_check_tag_ref(). Tags can't start with -
+ [A-Za-z0-9.-]*
+ [A-Za-z0-9-] # refs can't end with ".", see check_refname_format()
Also, the canonical documentation for what is allowed in refnames
is git-check-ref-format(1)... though it does not look like it includes
"tags cannot start with '-'".
Anyway, perhaps 'is it valid refname' could be passed to a subroutine,
or a named regexp (which might be more involved, like disallowing two
consecutive dots, e.g. "(?!.*\.{2})" at beginning).
> + -g[0-9a-fA-F]{7,40}
If we are limiting to git-describe output, we can get rid of A-F here.
> + |
> + # Just a normal looking Git SHA1
> + [0-9a-fA-F]{7,40}
> + )
> + \b
> + }{
> $cgi->a({-href => href(action=>"object", hash=>$1),
> -class => "text"}, $1);
> - }eg;
> + }egx;
>
> return $line;
> }
>
Good work.
I assume that you are using git-describe output in commit messages
a lot, isn't it?
--
Jakub Narębski
next prev parent reply other threads:[~2016-09-21 17:09 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-21 11:44 [PATCH 1/3] gitweb: Fix an ancient typo in v1.7.7-rc1-1-g0866786 Ævar Arnfjörð Bjarmason
2016-09-21 11:44 ` [PATCH 2/3] gitweb: Link to 7-character SHA1SUMS in commit messages Ævar Arnfjörð Bjarmason
2016-09-21 16:26 ` Jakub Narębski
2016-09-21 18:04 ` Ævar Arnfjörð Bjarmason
2016-09-21 18:28 ` Jakub Narębski
2016-09-21 20:09 ` Ævar Arnfjörð Bjarmason
2016-09-21 11:44 ` [PATCH 3/3] gitweb: Link to "git describe"'d commits in log messages Ævar Arnfjörð Bjarmason
2016-09-21 16:50 ` Junio C Hamano
2016-09-21 17:49 ` Jakub Narębski
2016-09-21 18:01 ` Junio C Hamano
2016-09-21 17:09 ` Jakub Narębski [this message]
2016-09-21 17:58 ` Ævar Arnfjörð Bjarmason
2016-09-21 19:13 ` Jakub Narębski
2016-09-21 13:33 ` [PATCH 1/3] gitweb: Fix an ancient typo in v1.7.7-rc1-1-g0866786 Jakub Narębski
2016-09-21 14:17 ` Ævar Arnfjörð Bjarmason
2016-09-21 17:14 ` Jakub Narębski
2016-09-21 17:17 ` Ævar Arnfjörð Bjarmason
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: http://vger.kernel.org/majordomo-info.html
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=fadd75f3-3737-1eaf-30f3-46a2ef132b27@gmail.com \
--to=jnareb@gmail.com \
--cc=avarab@gmail.com \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://80x24.org/mirrors/git.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).