Make the Python value for "default" evaluate as true in a Boolean context.

lib/python/Products/PageTemplates/TALES.py

@@ -15,7 +15,7 @@
 An implementation of a generic TALES engine
 """
 
-__version__='$Revision: 1.29 $'[11:-2]
+__version__='$Revision: 1.30 $'[11:-2]
 
 import re, sys, ZTUtils
 from MultiMapping import MultiMapping
@@ -40,8 +40,6 @@ class CompilerError(Exception):
 
 class Default:
     '''Retain Default'''
-    def __nonzero__(self):
-        return 0
 Default = Default()
 
 _marker = []

lib/python/TAL/DummyEngine.py

@@ -22,7 +22,9 @@ import driver
 
 from TALDefs import NAME_RE, TALESError, ErrorInfo
 
-Default = []
+class Default:
+    pass
+Default = Default()
 
 name_match = re.compile(r"(?s)(%s):(.*)\Z" % NAME_RE).match