[PATCH 6/6] gitweb: use blame --porcelain

[Junio C Hamano <junkio@cox.net>]

This makes gitweb (git_blame2) to use "blame --porcelain", which
lets the caller to figure out which line in the original version
each line comes from.  Using this information, change the
behaviour of clicking the line number to go to the line of the
blame output for the original commit.

Before, clicking the line number meant "scoll up to show this
line at the beginning of the page", which was not all that
useful.  The new behaviour lets you click on the line you are
interested in to view the line in the context it was introduced,
and keep digging deeper as you examine it.

Signed-off-by: Junio C Hamano <junkio@cox.net>
---

 * I've tested this only very lightly but it seems to be quite
   pleasant to use.

 gitweb/gitweb.perl |   65 +++++++++++++++++++++++++++++++++++----------------
 1 files changed, 44 insertions(+), 21 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index d217187..29a56c3 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -971,6 +971,9 @@ sub parse_date {
 	$date{'hour_local'} = $hour;
 	$date{'minute_local'} = $min;
 	$date{'tz_local'} = $tz;
+	$date{'iso-tz'} = sprintf ("%04d-%02d-%02d %02d:%02d:%02d %s",
+				   1900+$year, $mon+1, $mday,
+				   $hour, $min, $sec, $tz);
 	return %date;
 }
 
@@ -2496,7 +2499,8 @@ sub git_blame2 {
 	if ($ftype !~ "blob") {
 		die_error("400 Bad Request", "Object is not a blob");
 	}
-	open ($fd, "-|", git_cmd(), "blame", '-l', '--', $file_name, $hash_base)
+	open ($fd, "-|", git_cmd(), "blame", '--porcelain', '--',
+	      $file_name, $hash_base)
 		or die_error(undef, "Open git-blame failed");
 	git_header_html();
 	my $formats_nav =
@@ -2520,33 +2524,52 @@ sub git_blame2 {
 <table class="blame">
 <tr><th>Commit</th><th>Line</th><th>Data</th></tr>
 HTML
-	while (<$fd>) {
-		my ($full_rev, $author, $date, $lineno, $data) =
-			/^([0-9a-f]{40}).*?\s\((.*?)\s+([-\d]+ [:\d]+ [-+\d]+)\s+(\d+)\)\s(.*)/;
+	my %metainfo = ();
+	while (1) {
+		$_ = <$fd>;
+		last unless defined $_;
+		my ($full_rev, $lineno, $orig_lineno, $group_size) =
+		    /^([0-9a-f]{40}) (\d+) (\d+)(?: (\d+))?$/;
+		if (!exists $metainfo{$full_rev}) {
+			$metainfo{$full_rev} = {};
+		}
+		my $meta = $metainfo{$full_rev};
+		while (<$fd>) {
+			last if (s/^\t//);
+			if (/^(\S+) (.*)$/) {
+				$meta->{$1} = $2;
+			}
+		}
+		my $data = $_;
 		my $rev = substr($full_rev, 0, 8);
-		my $print_c8 = 0;
-
-		if (!defined $last_rev) {
-			$last_rev = $full_rev;
-			$print_c8 = 1;
-		} elsif ($last_rev ne $full_rev) {
-			$last_rev = $full_rev;
+		my $author = $meta->{'author'};
+		my %date = parse_date($meta->{'author-time'},
+				      $meta->{'author-tz'});
+		my $date = $date{'iso-tz'};
+		if ($group_size) {
 			$current_color = ++$current_color % $num_colors;
-			$print_c8 = 1;
 		}
 		print "<tr class=\"$rev_color[$current_color]\">\n";
-		print "<td class=\"sha1\"";
-		if ($print_c8 == 1) {
+		if ($group_size) {
+			print "<td class=\"sha1\"";
 			print " title=\"$author, $date\"";
-		}
-		print ">";
-		if ($print_c8 == 1) {
-			print $cgi->a({-href => href(action=>"commit", hash=>$full_rev, file_name=>$file_name)},
+			print " rowspan=\"$group_size\"" if ($group_size > 1);
+			print ">";
+			print $cgi->a({-href => href(action=>"commit",
+						     hash=>$full_rev,
+						     file_name=>$file_name)},
 				      esc_html($rev));
+			print "</td>\n";
 		}
-		print "</td>\n";
-		print "<td class=\"linenr\"><a id=\"l$lineno\" href=\"#l$lineno\" class=\"linenr\">" .
-		      esc_html($lineno) . "</a></td>\n";
+		my $blamed = href(action => 'blame',
+				  file_name => $meta->{'filename'},
+				  hash_base => $full_rev);
+		print "<td class=\"linenr\">";
+		print $cgi->a({ -href => "$blamed#l$lineno",
+				-id => "l$lineno",
+				-class => "linenr" },
+			      esc_html($lineno));
+		print "</td>";
 		print "<td class=\"pre\">" . esc_html($data) . "</td>\n";
 		print "</tr>\n";
 	}
-- 
1.4.2.3.g866f3