gitweb: provide a routine to display (sub)sections

The routine puts the given contento into a DIV element, automatically
adding a header div. The content can be provided as a standard scalar
value (which is used as-is), as a scalar ref (which is HTML-escaped), as
a function reference to be executed, or as a file handle to be dumped.

Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Acked-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 6e7a663..64da0cc 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -3802,6 +3802,44 @@
 	return "<tr class=\"metadata_url\"><td>$name</td><td>$url</td></tr>\n";
 }
 
+# Group output by placing it in a DIV element and adding a header.
+# Options for start_div() can be provided by passing a hash reference as the
+# first parameter to the function.
+# Options to git_print_header_div() can be provided by passing an array
+# reference. This must follow the options to start_div if they are present.
+# The content can be a scalar, which is output as-is, a scalar reference, which
+# is output after html escaping, an IO handle passed either as *handle or
+# *handle{IO}, or a function reference. In the latter case all following
+# parameters will be taken as argument to the content function call.
+sub git_print_section {
+	my ($div_args, $header_args, $content);
+	my $arg = shift;
+	if (ref($arg) eq 'HASH') {
+		$div_args = $arg;
+		$arg = shift;
+	}
+	if (ref($arg) eq 'ARRAY') {
+		$header_args = $arg;
+		$arg = shift;
+	}
+	$content = $arg;
+
+	print $cgi->start_div($div_args);
+	git_print_header_div(@$header_args);
+
+	if (ref($content) eq 'CODE') {
+		$content->(@_);
+	} elsif (ref($content) eq 'SCALAR') {
+		print esc_html($$content);
+	} elsif (ref($content) eq 'GLOB' or ref($content) eq 'IO::Handle') {
+		print <$content>;
+	} elsif (!ref($content) && defined($content)) {
+		print $content;
+	}
+
+	print $cgi->end_div;
+}
+
 sub print_local_time {
 	print format_local_time(@_);
 }