Re: [PATCH v2 3/3] gitweb: Link to "git describe"'d commits in log messages

> Change the log formatting function to know about "git describe" output
> such as "v2.8.0-4-g867ad08", in addition to just plain "867ad08".
>
> 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 which won't be picked up by this regex.

> 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.
>
> There was on-list discussion about how we could do better than this
> patch. Junio suggested to update parse_commits() to call a new
> "gitweb--helper" command which would pass each of the revision
> candidates through "rev-parse --verify --quiet". That would cut down
> on our false positives (e.g. we'll link to "deadbeef"), and also allow
> us to be more aggressive in selecting candidate revisions.
>
> That may be too expensive to work in practice, or it may
> not. Investigating that would be a good follow-up to this patch.
>
> Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
> ---
>  gitweb/gitweb.perl | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> index 92b5e91..7cf68f0 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
> +            (?<!-) # see strbuf_check_tag_ref(). Tags can't start with -
> +            [A-Za-z0-9.-]+
> +            (?!\.) # refs can't end with ".", see check_refname_format()
> +            -g[0-9a-fA-F]{7,40}
> +            |
> +            # 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;
>  }