bpo-31632: fix set_protocol() in _SSLProtocolTransport (GH-3817) (GH-3817) (#4052)

(cherry picked from commit ea2ef5d)

Author: miss-islington

Lib/asyncio/sslproto.py

@@ -294,22 +294,21 @@ def feed_appdata(self, data, offset=0):
 class _SSLProtocolTransport(transports._FlowControlMixin,
                             transports.Transport):
 
-    def __init__(self, loop, ssl_protocol, app_protocol):
+    def __init__(self, loop, ssl_protocol):
         self._loop = loop
         # SSLProtocol instance
         self._ssl_protocol = ssl_protocol
-        self._app_protocol = app_protocol
         self._closed = False
 
     def get_extra_info(self, name, default=None):
         """Get optional transport information."""
         return self._ssl_protocol._get_extra_info(name, default)
 
     def set_protocol(self, protocol):
-        self._app_protocol = protocol
+        self._ssl_protocol._app_protocol = protocol
 
     def get_protocol(self):
-        return self._app_protocol
+        return self._ssl_protocol._app_protocol
 
     def is_closing(self):
         return self._closed
@@ -436,8 +435,7 @@ def __init__(self, loop, app_protocol, sslcontext, waiter,
         self._waiter = waiter
         self._loop = loop
         self._app_protocol = app_protocol
-        self._app_transport = _SSLProtocolTransport(self._loop,
-                                                    self, self._app_protocol)
+        self._app_transport = _SSLProtocolTransport(self._loop, self)
         # _SSLPipe instance (None until the connection is made)
         self._sslpipe = None
         self._session_established = False

Lib/test/test_asyncio/test_sslproto.py

@@ -121,6 +121,14 @@ def test_get_extra_info_on_closed_connection(self):
         ssl_proto.connection_lost(None)
         self.assertIsNone(ssl_proto._get_extra_info('socket'))
 
+    def test_set_new_app_protocol(self):
+        waiter = asyncio.Future(loop=self.loop)
+        ssl_proto = self.ssl_protocol(waiter)
+        new_app_proto = asyncio.Protocol()
+        ssl_proto._app_transport.set_protocol(new_app_proto)
+        self.assertIs(ssl_proto._app_transport.get_protocol(), new_app_proto)
+        self.assertIs(ssl_proto._app_protocol, new_app_proto)
+
 
 if __name__ == '__main__':
     unittest.main()

Misc/ACKS

@@ -849,6 +849,7 @@ Vladimir Kushnir
 Erno Kuusela
 Ross Lagerwall
 Cameron Laird
+Loïc Lajeanne
 David Lam
 Thomas Lamb
 Valerie Lambert

Misc/NEWS.d/next/Library/2017-10-04-11-37-14.bpo-31632.LiOC3C.rst

@@ -0,0 +1,2 @@
+Fix method set_protocol() of class _SSLProtocolTransport in asyncio module.
+This method was previously modifying a wrong reference to the protocol.