gitweb: ref markers link to named shortlogs

This patch turns ref markers for tags and heads into links to
appropriate views for the ref name, depending on current context.

For annotated tags, we link to the tag view, unless that's the current
view, in which case we switch to shortlog. For other refs, we prefer the
current view if it's history or (short)log, and default to shortlog
otherwise.

Appropriate changes are made in the CSS to prevent ref markers from
being annoyingly blue and underlined, unless hovered. A visual
indication of the target view difference is also implemented by making
annotated tags show up in italic.

Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Acked-by: Petr Baudis <pasky@suse.cz>
Acked-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

gitweb/gitweb.css

@@ -481,6 +481,19 @@ span.refs span {
 	border-color: #ffccff #ff00ee #ff00ee #ffccff;
 }
 
+span.refs span a {
+	text-decoration: none;
+	color: inherit;
+}
+
+span.refs span a:hover {
+	text-decoration: underline;
+}
+
+span.refs span.indirect {
+	font-style: italic;
+}
+
 span.refs span.ref {
 	background-color: #aaaaff;
 	border-color: #ccccff #0033cc #0033cc #ccccff;

gitweb/gitweb.perl

@@ -1090,13 +1090,23 @@ sub format_log_line_html {
 }
 
 # format marker of refs pointing to given object
+
+# the destination action is chosen based on object type and current context:
+# - for annotated tags, we choose the tag view unless it's the current view
+#   already, in which case we go to shortlog view
+# - for other refs, we keep the current view if we're in history, shortlog or
+#   log view, and select shortlog otherwise
 sub format_ref_marker {
 	my ($refs, $id) = @_;
 	my $markers = '';
 
 	if (defined $refs->{$id}) {
 		foreach my $ref (@{$refs->{$id}}) {
+			# this code exploits the fact that non-lightweight tags are the
+			# only indirect objects, and that they are the only objects for which
+			# we want to use tag instead of shortlog as action
 			my ($type, $name) = qw();
+			my $indirect = ($ref =~ s/\^\{\}$//);
 			# e.g. tags/v2.6.11 or heads/next
 			if ($ref =~ m!^(.*?)s?/(.*)$!) {
 				$type = $1;
@@ -1106,8 +1116,29 @@ sub format_ref_marker {
 				$name = $ref;
 			}
 
-			$markers .= " <span class=\"$type\" title=\"$ref\">" .
-			            esc_html($name) . "</span>";
+			my $class = $type;
+			$class .= " indirect" if $indirect;
+
+			my $dest_action = "shortlog";
+
+			if ($indirect) {
+				$dest_action = "tag" unless $action eq "tag";
+			} elsif ($action =~ /^(history|(short)?log)$/) {
+				$dest_action = $action;
+			}
+
+			my $dest = "";
+			$dest .= "refs/" unless $ref =~ m!^refs/!;
+			$dest .= $ref;
+
+			my $link = $cgi->a({
+				-href => href(
+					action=>$dest_action,
+					hash=>$dest
+				)}, $name);
+
+			$markers .= " <span class=\"$class\" title=\"$ref\">" .
+				$link . "</span>";
 		}
 	}
 
@@ -1918,7 +1949,7 @@ sub git_get_references {
 
 	while (my $line = <$fd>) {
 		chomp $line;
-		if ($line =~ m!^([0-9a-fA-F]{40})\srefs/($type/?[^^]+)!) {
+		if ($line =~ m!^([0-9a-fA-F]{40})\srefs/($type.*)$!) {
 			if (defined $refs{$1}) {
 				push @{$refs{$1}}, $2;
 			} else {