Hello, The patch (attached) is quiet simple.
-- Dr. Ludovic Rousseau
--- /usr/lib/cgi-bin/drraw/drraw.cgi 2013-08-08 14:39:24.959363577 +0200 +++ /home/lroussea/drraw.cgi 2013-08-08 14:38:44.307362370 +0200 @@ -273,7 +273,7 @@ } # Make sure that %datadirs is defined -if ( !defined(%datadirs) ) { +if ( ! %datadirs ) { print header(-status=>500), start_html('500 Internal error'), @@ -665,7 +665,7 @@ } print $IndexJS; - &CustomIndex(\%Index, '') if ( defined(%Index) ); + &CustomIndex(\%Index, '') if ( %Index ); if ( defined(param('Browse')) && param('Browse') eq 'AllGraphs' ) { print