fix: do not abort client conn transport on close

Author: ordinary-jamie

Lib/asyncio/proactor_events.py

@@ -62,12 +62,8 @@ def __init__(self, loop, sock, protocol, waiter=None,
         self._closing = False  # Set when close() called.
         self._called_connection_lost = False
         self._eof_written = False
-        if self._server is not None:
-            if self._server.is_serving():
-                self._server._attach(self)
-            else:
-                self.abort()
-                return
+        if self._server is not None and self._server.is_serving():
+            self._server._attach(self)
         self._loop.call_soon(self._protocol.connection_made, self)
         if waiter is not None:
             # only wake up the waiter when connection_made() has been called

Lib/asyncio/selector_events.py

@@ -794,12 +794,8 @@ def __init__(self, loop, sock, protocol, extra=None, server=None):
         self._closing = False  # Set when close() called.
         self._paused = False  # Set when pause_reading() called
 
-        if self._server is not None:
-            if self._server.is_serving():
-                self._server._attach(self)
-            else:
-                self.abort()
-                return
+        if self._server is not None and self._server.is_serving():
+            self._server._attach(self)
 
         loop._transports[self._sock_fd] = self
 

Lib/test/test_asyncio/test_server.py

@@ -272,29 +272,6 @@ async def serve(rd, wr):
         await asyncio.sleep(0)
         self.assertTrue(task.done())
 
-    async def test_close_before_transport_attach(self):
-        proto = Mock()
-        loop = asyncio.get_running_loop()
-        srv = await loop.create_server(lambda *_: proto, socket_helper.HOSTv4, 0)
-
-        await srv.start_serving()
-        addr = srv.sockets[0].getsockname()
-
-        # Create a connection to the server but close the server before the
-        # socket transport for the connection is created and attached
-        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
-            s.connect(addr)
-        await asyncio.sleep(0)  # loop select reader
-        await asyncio.sleep(0)  # accept conn 1
-        srv.close()
-
-        # Ensure the protocol is given an opportunity to handle this event
-        # gh109564: the transport would be unclosed and will cause a loop
-        # exception due to a double-call to Server._wakeup
-        await asyncio.sleep(0)
-        await asyncio.sleep(0)
-        proto.connection_lost.assert_called()
-
 
 # Test the various corner cases of Unix server socket removal
 class UnixServerCleanupTests(unittest.IsolatedAsyncioTestCase):