Fixed: Synchonizers that registered with transaction managers when

  transactions were in progress didn't have their newTransaction
  methods called to let them know of the in-progress transactions.

CHANGES.rst

 Changes
 =======
 
+1.6.1 (unreleased)
+------------------
+
+- Fixed: Synchonizers that registered with transaction managers when
+  transactions were in progress didn't have their newTransaction
+  methods called to let them know of the in-progress transactions.
+
 1.6.0 (2016-05-21)
 ------------------
 

transaction/_manager.py

@@ -89,6 +89,8 @@ class TransactionManager(object):
         """ See ITransactionManager.
         """
         self._synchs.add(synch)
+        if self._txn is not None:
+            synch.newTransaction(self._txn)
 
     def unregisterSynch(self, synch):
         """ See ITransactionManager.

transaction/tests/test__manager.py

@@ -442,6 +442,27 @@ class TransactionManagerTests(unittest.TestCase):
 
         assert nosub1._p_jar.ctpc_abort == 1
 
+    def test_notify_transaction_late_comers(self):
+        # If a datamanager registers for synchonization after a
+        # transaction has started, we should call newTransaction so it
+        # can do necessry setup.
+        import mock
+        from .. import TransactionManager
+        manager = TransactionManager()
+        sync1 = mock.MagicMock()
+        manager.registerSynch(sync1)
+        sync1.newTransaction.assert_not_called()
+        t = manager.begin()
+        sync1.newTransaction.assert_called_with(t)
+        sync2 = mock.MagicMock()
+        manager.registerSynch(sync2)
+        sync2.newTransaction.assert_called_with(t)
+
+        # for, um, completeness
+        t.commit()
+        for s in sync1, sync2:
+            s.beforeCompletion.assert_called_with(t)
+            s.afterCompletion.assert_called_with(t)
 
 class AttemptTests(unittest.TestCase):