fix bug in xml_escape_attrib

diff --git a/data/PVE/Cluster.pm b/data/PVE/Cluster.pm
index 9f8ef8ec2e9dd1bbb97ea34462aa46d28fdb7cd2..a8791438ca64c856557b86d2fe7229d5e555a293 100644 (file)
--- a/data/PVE/Cluster.pm
+++ b/data/PVE/Cluster.pm
@@ -1296,7 +1296,7 @@ sub cluster_conf_version {
 sub xml_escape_attrib {
     my ($data) = @_;
 
-    return '' if !$data;
+    return '' if !defined($data);
 
     $data =~ s/&/&/sg;
     $data =~ s/</&lt;/sg;