extra.indexed_attrs is now optional. leaving this input field

empty lead to an empty index.

lib/python/Products/PluginIndexes/common/UnIndex.py

@@ -13,7 +13,7 @@
 
 """Simple column indices"""
 
-__version__='$Revision: 1.17 $'[11:-2]
+__version__='$Revision: 1.18 $'[11:-2]
 
 from Globals import Persistent
 from Acquisition import Implicit
@@ -88,7 +88,8 @@ class UnIndex(Persistent, Implicit, SimpleItem):
         try: 
             self.indexed_attrs = extra.indexed_attrs.split(',')
             self.indexed_attrs = [ attr.strip() for attr in  self.indexed_attrs if attr ]
-        except: self.indexed_attrs = [ self.id ]
+        except: pass 
+        if len(self.indexed_attrs) == 0: self.indexed_attrs = [ self.id ]
         
         self.__len__=BTrees.Length.Length() # see __len__ method docstring
         self.clear()