VarParsing: prevent TypeError for default of int/float/bool list

Author: IzaakWN

FWCore/ParameterSet/python/VarParsing.py

@@ -413,8 +413,9 @@ def register (self, name,
             self._lists[name] = []
             # if it's a list, we only want to use the default if it
             # does exist.
-            if len (default):
-                self._lists[name].append (default)
+            if (mytype in [VarParsing.varType.bool, VarParsing.varType.int, VarParsing.varType.float] and \
+               default != "") or len (default): # check type to prevent TypeError for bool/int/float defaults
+                self._lists[name].append (default) # known bug: default can be list
         #######################################
         ## Process any additional directives ##
         #######################################