doc/CHANGES.txt

@@ -24,6 +24,16 @@ Zope Changes
 
    - check if ExtendedPathIndex might be a reasonable replacement for PathIndex
 
+
+  after Zope 2.8a2 
+
+    Features added
+
+    Bugs fixed
+
+      - Collector #1721: Fixed handling of an empty indexed_attrs parameter
+
+
   Zope 2.8a2 (2005/04/02)
 
     Features added

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

@@ -94,6 +94,8 @@ class UnIndex(SimpleItem):
         else:
             self.indexed_attrs = list(ia)
         self.indexed_attrs = [ attr.strip() for attr in  self.indexed_attrs if attr ] 
+        if not self.indexed_attrs:
+            self.indexed_attrs = [id]
 
         self._length = BTrees.Length.Length()
         self.clear()