Fixing two small bugs uncovered by unit testing (I was testing the

Minimal BSDDB storage which does not override abortVersion() and
commitVersion()).

commitVersion() can't be an alias for abortVersion() because it takes
a different number of arguments.  Provide a simple implementation.

Changed "from POSException import UndoError" to "import POSException"
and use POSException.UndoError in undo().  This is because
abortVersion() and commitVersion() also reference exceptions in the
POSException module.

Aside: fix __version__ extraction from $Revision$ to be portable in
the face of "cvs co -kv".

src/ZODB/BaseStorage.py

@@ -84,11 +84,13 @@
 ##############################################################################
 """Handy standard storage machinery
 """
-__version__='$Revision: 1.11 $'[11:-2]
+# Do this portably in the face of checking out with -kv
+import string
+__version__ = string.split('$Revision: 1.12 $')[-2:][0]
 
 import ThreadLock, bpthread
 import time, UndoLogCompatible
-from POSException import UndoError
+import POSException
 from TimeStamp import TimeStamp
 z64='\0'*8
 
@@ -120,9 +122,12 @@ class BaseStorage(UndoLogCompatible.UndoLogCompatible):
             raise POSException.StorageTransactionError(self, transaction)
         return []
 
-    def close(self): pass
+    def commitVersion(self, src, dest, transaction):
+        if transaction is not self._transaction:
+            raise POSException.StorageTransactionError(self, transaction)
+        return []
 
-    commitVersion=abortVersion
+    def close(self): pass
 
     def getName(self): return self.__name__
     def getSize(self): return len(self)*300 # WAG!
@@ -224,7 +229,7 @@ class BaseStorage(UndoLogCompatible.UndoLogCompatible):
         pass
 
     def undo(self, transaction_id):
-        raise UndoError, 'non-undoable transaction'
+        raise POSException.UndoError, 'non-undoable transaction'
 
     def undoLog(self, first, last, filter=None): return ()