Issue #28990: Fix SSL hanging if connection is closed before handshake completed.

Lib/asyncio/sslproto.py

@@ -479,6 +479,7 @@ def connection_lost(self, exc):
             self._loop.call_soon(self._app_protocol.connection_lost, exc)
         self._transport = None
         self._app_transport = None
+        self._wakeup_waiter(exc)
 
     def pause_writing(self):
         """Called when the low-level transport's buffer goes over

Lib/test/test_asyncio/test_sslproto.py

@@ -85,5 +85,15 @@ def test_fatal_error_no_name_error(self):
             # Restore error logging.
             log.logger.setLevel(log_level)
 
+    def test_connection_lost(self):
+        # From issue #472.
+        # yield from waiter hang if lost_connection was called.
+        waiter = asyncio.Future(loop=self.loop)
+        ssl_proto = self.ssl_protocol(waiter)
+        self.connection_made(ssl_proto)
+        ssl_proto.connection_lost(ConnectionAbortedError)
+        test_utils.run_briefly(self.loop)
+        self.assertIsInstance(waiter.exception(), ConnectionAbortedError)
+
 if __name__ == '__main__':
     unittest.main()

Misc/NEWS

@@ -485,6 +485,10 @@ Library
 - Issue #24142: Reading a corrupt config file left the parser in an
   invalid state.  Original patch by Florian Höch.
 
+- Issue #28990: Fix SSL hanging if connection is closed before handshake 
+  completed.
+  (Patch by HoHo-Ho)
+
 IDLE
 ----