+ elsif ($key eq 'stylesheet') {
+ my $rel=exists $params{rel} ? $params{rel} : "alternate stylesheet";
+ my $title=exists $params{title} ? $params{title} : $value;
+ # adding .css to the value prevents using any old web
+ # editable page as a stylesheet
+ my $stylesheet=bestlink($page, $value.".css");
+ if (! length $stylesheet) {
+ return "[[meta ".gettext("stylesheet not found")."]]";
+ }
+ push @{$metaheaders{$page}}, '<link href="'.urlto($stylesheet, $page).
+ '" rel="'.encode_entities($rel).
+ '" title="'.encode_entities($title).
+ "\" type=\"text/css\" />";
+ }
+ elsif ($key eq 'openid') {
+ if (exists $params{server}) {
+ push @{$metaheaders{$page}}, '<link href="'.encode_entities($params{server}).
+ '" rel="openid.server" />';
+ }
+ push @{$metaheaders{$page}}, '<link href="'.encode_entities($value).
+ '" rel="openid.delegate" />';
+ }
+ elsif ($key eq 'redir') {
+ return "" if $page ne $destpage;
+ my $safe=0;
+ if ($value !~ /^\w+:\/\//) {
+ my ($redir_page, $redir_anchor) = split /\#/, $value;
+
+ add_depends($page, $redir_page);
+ my $link=bestlink($page, $redir_page);
+ if (! length $link) {
+ return "[[meta ".gettext("redir page not found")."]]";
+ }
+
+ $value=urlto($link, $page);
+ $value.='#'.$redir_anchor if defined $redir_anchor;
+ $safe=1;
+
+ # redir cycle detection
+ $pagestate{$page}{meta}{redir}=$link;
+ my $at=$page;
+ my %seen;
+ while (exists $pagestate{$at}{meta}{redir}) {
+ if ($seen{$at}) {
+ return "[[meta ".gettext("redir cycle is not allowed")."]]";
+ }
+ $seen{$at}=1;
+ $at=$pagestate{$at}{meta}{redir};
+ }