- Use 'del' instead of 'list.remove()' in
        Catalog.delColumn(). There can be only one column with the
        same name, and it could potentially break catalog metadata as
        remove() may remove more than one element from the list if
        they have the same value. Also, we already have the list index
        we are interested in deleting so it doesn't make sense to look
        up the value and call 'list.remove()' on it.

doc/CHANGES.txt

@@ -58,6 +58,14 @@ Zope Changes
 
     Bugs fixed
 
+      - Use 'del' instead of 'list.remove()' in
+        Catalog.delColumn(). There can be only one column with the
+        same name, and it could potentially break catalog metadata as
+        remove() may remove more than one element from the list if
+        they have the same value. Also, we already have the list index
+        we are interested in deleting so it doesn't make sense to look
+        up the value and call 'list.remove()' on it.
+
       - Collector #1628: FTP server has been broken (directory
         listings did not work)
 

lib/python/Products/ZCatalog/Catalog.py

@@ -206,7 +206,7 @@ class Catalog(Persistent, Acquisition.Implicit, ExtensionClass.Base):
             LOG.error('delColumn attempted to delete nonexistent column %s.' % str(name))
             return
 
-        names.remove(name)
+        del names[_index]
 
         # rebuild the schema
         i=0; schema = {}
@@ -223,7 +223,7 @@ class Catalog(Persistent, Acquisition.Implicit, ExtensionClass.Base):
         # remove the column value from each record
         for key in self.data.keys():
             rec = list(self.data[key])
-            rec.remove(rec[_index])
+            del rec[_index]
             self.data[key] = tuple(rec)
 
     def addIndex(self, name, index_type):