Re-add plaintext upgrade code.

Author: Lukasa

hyper/common/connection.py

@@ -137,13 +137,9 @@ def get_response(self, *args, **kwargs):
                 self._host, self._port, **self._h2_kwargs
             )
 
-            self._conn._sock = e.sock
+            self._conn._connect_upgrade(e.sock)
             # stream id 1 is used by the upgrade request and response
             # and is half-closed by the client
-            self._conn._new_stream(stream_id=1, local_closed=True)
-
-            # HTTP/2 preamble must be sent after receipt of a HTTP/1.1 101
-            self._conn._send_preamble()
 
             return self._conn.get_response(1)
 

hyper/http20/connection.py

@@ -357,6 +357,27 @@ def connect(self):
 
             self._send_preamble()
 
+    def _connect_upgrade(self, sock):
+        """
+        Called by the generic HTTP connection when we're being upgraded. Locks
+        in a new socket and places the backing state machine into an upgrade
+        state, then sends the preamble.
+        """
+        self._sock = sock
+
+        with self._conn as conn:
+            conn.initiate_upgrade_connection()
+            conn.update_settings(
+                {h2.settings.ENABLE_PUSH: int(self._enable_push)}
+            )
+        self._send_outstanding_data()
+
+        # The server will also send an initial settings frame, so get it.
+        self._recv_cb()
+
+        s = self._new_stream(local_closed=True)
+        self.recent_stream = s
+
     def _send_preamble(self):
         """
         Sends the necessary HTTP/2 preamble.

test/test_abstraction.py

@@ -110,6 +110,9 @@ def __init__(self, host, port=None, secure=None, **kwargs):
     def _send_preamble(self):
         pass
 
+    def _connect_upgrade(self, sock):
+        self._sock = sock
+
     def _new_stream(self, *args, **kwargs):
         pass