There were some tests that tested for failure, but that didn't

recognize other valid failure modes.

src/ZODB/tests/BasicStorage.py

@@ -26,14 +26,36 @@ class BasicStorage:
             POSException.StorageTransactionError,
             self._storage.store,
             0, 0, 0, 0, Transaction())
-        self.assertRaises(
-            POSException.StorageTransactionError,
-            self._storage.abortVersion,
-            0, Transaction())
-        self.assertRaises(
-            POSException.StorageTransactionError,
-            self._storage.commitVersion,
-            0, 1, Transaction())
+
+        #JF# The following will fail two ways. UnitTest doesn't
+        #JF# help us here:
+        #JF# self.assertRaises(
+        #JF#     POSException.StorageTransactionError,
+        #JF#     self._storage.abortVersion,
+        #JF#     0, Transaction())
+
+        #JF# but we can do it another way:
+        try:
+            self._storage.abortVersion('dummy', Transaction())
+        except (POSException.StorageTransactionError,
+                POSException.VersionCommitError):
+            pass # test passed ;)
+        else:
+            assert 0, "Should have failed, invalid transaction."
+
+        #JF# ditto
+        #JF# self.assertRaises(
+        #JF#     POSException.StorageTransactionError,
+        #JF#     self._storage.commitVersion,
+        #JF#     0, 1, Transaction())
+        try:
+            self._storage.commitVersion('dummy', 'dummer', Transaction())
+        except (POSException.StorageTransactionError,
+                POSException.VersionCommitError):
+            pass # test passed ;)
+        else:
+            assert 0, "Should have failed, invalid transaction."
+
         self.assertRaises(
             POSException.StorageTransactionError,
             self._storage.store,