#133 Issue on object creation with fields set to 'null'

git-svn-id: http://svn.code.sf.net/p/itop/code/trunk@444 a333f486-631f-4898-b8df-5754b55c2be0

core/cmdbsource.class.inc.php

@@ -159,6 +159,11 @@ class CMDBSource
 		// otherwise and if there is a mix of strings and numbers, the clause
 		// would always be false
 
+		if (is_null($value))
+		{
+			return 'NULL';
+		}
+
 		if (is_array($value))
 		{
 			$aRes = array();