Only bind in __enter__

Author: aclark4life

pymongo/asynchronous/mongo_client.py

@@ -65,7 +65,7 @@
 from pymongo.asynchronous import client_session, database, uri_parser
 from pymongo.asynchronous.change_stream import AsyncChangeStream, AsyncClusterChangeStream
 from pymongo.asynchronous.client_bulk import _AsyncClientBulk
-from pymongo.asynchronous.client_session import _SESSION, _EmptyServerSession
+from pymongo.asynchronous.client_session import _EmptyServerSession
 from pymongo.asynchronous.command_cursor import AsyncCommandCursor
 from pymongo.asynchronous.settings import TopologySettings
 from pymongo.asynchronous.topology import Topology, _ErrorContext
@@ -1355,11 +1355,7 @@ def _close_cursor_soon(
     def _start_session(self, implicit: bool, **kwargs: Any) -> AsyncClientSession:
         server_session = _EmptyServerSession()
         opts = client_session.SessionOptions(**kwargs)
-        bind = opts._bind
-        session = client_session.AsyncClientSession(self, server_session, opts, implicit)
-        if bind:
-            _SESSION.set(session)
-        return session
+        return client_session.AsyncClientSession(self, server_session, opts, implicit)
 
     def start_session(
         self,

pymongo/synchronous/mongo_client.py

@@ -107,7 +107,7 @@
 from pymongo.synchronous import client_session, database, uri_parser
 from pymongo.synchronous.change_stream import ChangeStream, ClusterChangeStream
 from pymongo.synchronous.client_bulk import _ClientBulk
-from pymongo.synchronous.client_session import _SESSION, _EmptyServerSession
+from pymongo.synchronous.client_session import _EmptyServerSession
 from pymongo.synchronous.command_cursor import CommandCursor
 from pymongo.synchronous.settings import TopologySettings
 from pymongo.synchronous.topology import Topology, _ErrorContext
@@ -1353,11 +1353,7 @@ def _close_cursor_soon(
     def _start_session(self, implicit: bool, **kwargs: Any) -> ClientSession:
         server_session = _EmptyServerSession()
         opts = client_session.SessionOptions(**kwargs)
-        bind = opts._bind
-        session = client_session.ClientSession(self, server_session, opts, implicit)
-        if bind:
-            _SESSION.set(session)
-        return session
+        return client_session.ClientSession(self, server_session, opts, implicit)
 
     def start_session(
         self,