fix for cases when SCRIPT_NAME is empty, ie the cvsweb script is handler to whole vhost:

<VirtualHost *:80>
    ServerName cvs

    DocumentRoot /usr/share/cvsweb/cvsweb.cgi
    <Location />
        Options ExecCGI
    </Location>
</VirtualHost>

--- cvsweb-3.0.6/cvsweb.cgi	2006-01-09 23:56:57.000000000 +0200
+++ /tmp/cvsweb.cgi	2006-01-10 00:59:36.000000000 +0200
@@ -299,7 +299,7 @@
 $where         =  $pathinfo;
 $doCheckout    =  $where =~ s|^/$CheckoutMagic/|/|o;
 $where         =~ s|^/||;
-$scriptname    =~ s|^/*|/|;
+$scriptname    =~ s|^/*|/| if $scriptname;
 
 # Let's workaround thttpd's stupidity..
 if ($scriptname =~ m|/$|) {