-# Use the stated preferred URL or figure it out automatically
-$url ||= url( -path_info => 1 );
-$url =~ s/^included:/http:/ if $ENV{SERVER_PROTOCOL} eq 'INCLUDED';
+# Use the stated preferred URL or figure it out automatically. Set
+# $url manually in the config section above if CGI.pm doesn't guess
+# the base URL correctly, e.g. when called from a Server Side Includes
+# document or so.
+unless ($url) {
+ $url = url();
+
+ # Unescape %XX hex codes (from URI::Escape::uri_unescape)
+ $url =~ s/%([0-9A-Fa-f]{2})/chr(hex($1))/eg;
+
+ # Support being called from inside a SSI document
+ $url =~ s/^included:/http:/ if $ENV{SERVER_PROTOCOL} eq 'INCLUDED';
+
+ # Remove PATH_INFO if it is set but not removed by CGI.pm. This
+ # seems to happen when used with Apache's Alias directive or if
+ # called from inside a Server Side Include document. If that
+ # doesn't help either, set $url manually in the configuration.
+ $url =~ s/\Q$ENV{PATH_INFO}\E$// if defined $ENV{PATH_INFO};
+
+ # NOTE:
+ #
+ # There is one case where this code does more than necessary, too:
+ # If the URL requested is e.g. http://example.org/blog/blog and
+ # the base URL is correctly determined as http://example.org/blog
+ # by CGI.pm, then this code will incorrectly normalize the base
+ # URL down to http://example.org, because the same string as
+ # PATH_INFO is part of the base URL, too. But this is such a
+ # seldom case and can be fixed by setting $url in the config file,
+ # too.
+}