- merge r43460573c27a:4993c7eae8e5d117ff342bdc59f3b0635b898e2c of 0.6 branch

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/sqlalchemy/engine/threadlocal.py b/lib/sqlalchemy/engine/threadlocal.py
index 2ce0922bf..d4d0488a9 100644
--- a/lib/sqlalchemy/engine/threadlocal.py
+++ b/lib/sqlalchemy/engine/threadlocal.py
@@ -71,16 +71,28 @@ class TLEngine(base.Engine):
         if not hasattr(self._connections, 'trans'):
             self._connections.trans = []
         self._connections.trans.append(self.contextual_connect().begin_twophase(xid=xid))
+        return self
 
     def begin_nested(self):
         if not hasattr(self._connections, 'trans'):
             self._connections.trans = []
         self._connections.trans.append(self.contextual_connect().begin_nested())
+        return self
 
     def begin(self):
         if not hasattr(self._connections, 'trans'):
             self._connections.trans = []
         self._connections.trans.append(self.contextual_connect().begin())
+        return self
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, type, value, traceback):
+        if type is None:
+            self.commit()
+        else:
+            self.rollback()
 
     def prepare(self):
         if not hasattr(self._connections, 'trans') or \