asyncio: sync with Tulip

* Tulip issue 184: FlowControlMixin constructor now get the event loop if the
  loop parameter is not set. Add unit tests to ensure that constructor of
  StreamReader and StreamReaderProtocol classes get the event loop.
* Remove outdated TODO/XXX

1 files changed, 7 insertions, 3 deletions

diff --git a/Lib/asyncio/streams.py b/Lib/asyncio/streams.py
index c77eb60..5a96b24 100644
--- a/Lib/asyncio/streams.py
+++ b/Lib/asyncio/streams.py
@@ -145,7 +145,10 @@ class FlowControlMixin(protocols.Protocol):
     """
 
     def __init__(self, loop=None):
-        self._loop = loop  # May be None; we may never need it.
+        if loop is None:
+            self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
         self._paused = False
         self._drain_waiter = None
         self._connection_lost = False
@@ -306,8 +309,9 @@ class StreamReader:
         # it also doubles as half the buffer limit.
         self._limit = limit
         if loop is None:
-            loop = events.get_event_loop()
-        self._loop = loop
+            self._loop = events.get_event_loop()
+        else:
+            self._loop = loop
         self._buffer = bytearray()
         self._eof = False  # Whether we're done.
         self._waiter = None  # A future.