[PATCH/RFC 5/5] gitweb: Highlight matched part of shortened project description

[Jakub Narebski <jnareb@gmail.com>]

Previous commit make gitweb use esc_html_match_hl() to mark match in
the _whole_ description of a project when searching projects.

This commit makes gitweb highlight match in _shortened_ description,
based on match in whole description, using esc_html_match_hl_chopped()
subroutine (with some code duplication with esc_html_match_hl()).
If match is in shortened part, then trailing "... " is highlighted.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
---
This is an RFC because of code duplication between esc_html_match_hl()
and esc_html_match_hl_chopped().

 gitweb/gitweb.perl |   41 ++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 40 insertions(+), 1 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index c650268..174b4d2 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -1739,6 +1739,44 @@ sub esc_html_match_hl {
 	return $out;
 }
 
+# highlight match (if any) of shortened string, and escape HTML
+sub esc_html_match_hl_chopped {
+	my ($str, $chopped, $regexp) = @_;
+	return esc_html($chopped) unless defined $regexp;
+	return esc_html_match_hl($str, $regexp) if ($str eq $chopped);
+
+	my @matches;
+	while ($str =~ /$regexp/g) {
+		push @matches, [$-[0], $+[0]];
+	}
+	return esc_html($chopped) unless @matches;
+
+	my $tail = "... ";
+	$chopped =~ s/\Q$tail\E$//; # see chop_str
+	my $len = length($chopped);
+	my $out = '';
+	my $pos = 0;
+	for my $m (@matches) {
+		if ($m->[0] > $len) {
+			$tail = $cgi->span({-class => 'match'}, $tail);
+			last;
+		}
+		$out .= esc_html(substr $str, $pos, $m->[0] - $pos);
+		$out .= $cgi->span({-class => 'match'},
+		                   esc_html(substr $chopped, $m->[0],
+		                            ($m->[1] > $len ? $len : $m->[1]) - $m->[0]));
+		if ($m->[1] > $len) {
+			$tail = $cgi->span({-class => 'match'}, $tail);
+			$pos = $len;
+			last;
+		}
+		$pos = $m->[1];
+	}
+	$out .= esc_html(substr($chopped, $pos)).$tail;
+
+	return $out;
+}
+
 ## ----------------------------------------------------------------------
 ## functions returning short strings
 
@@ -5372,7 +5410,8 @@ sub git_project_list_rows {
 		      "<td>" . $cgi->a({-href => href(project=>$pr->{'path'}, action=>"summary"),
 		                        -class => "list", -title => $pr->{'descr_long'}},
 		                        $search_regexp
-		                        ? esc_html_match_hl($pr->{'descr_long'}, $search_regexp)
+		                        ? esc_html_match_hl_chopped($pr->{'descr_long'},
+		                                                    $pr->{'descr'}, $search_regexp)
 		                        : esc_html($pr->{'descr'})) .
 		      "</td>\n" .
 		      "<td><i>" . chop_and_escape_str($pr->{'owner'}, 15) . "</i></td>\n";
-- 
1.7.9