add test

Lib/asyncio/tasks.py

@@ -637,13 +637,13 @@ def ensure_future(coro_or_future, *, loop=None):
     should_close = False
     if not coroutines.iscoroutine(coro_or_future):
         if inspect.isawaitable(coro_or_future):
-            async def _wrap_awaitable():
+            async def _wrap_awaitable(awaitable):
                 @types.coroutine
                 def wrapper():
-                    return (yield from coro_or_future.__await__())
+                    return (yield from awaitable.__await__())
                 return await wrapper()
 
-            coro_or_future = _wrap_awaitable()
+            coro_or_future = _wrap_awaitable(coro_or_future)
             should_close = True
         else:
             raise TypeError('An asyncio.Future, a coroutine or an awaitable '

Lib/test/test_asyncio/test_tasks.py

@@ -8,6 +8,7 @@
 import re
 import sys
 import traceback
+import types
 import unittest
 from unittest import mock
 from types import GenericAlias
@@ -274,6 +275,20 @@ async def coro():
         loop.run_until_complete(fut)
         self.assertEqual(fut.result(), 'ok')
 
+    def test_ensure_future_task_awaitable(self):
+        class Aw:
+            def __await__(self):
+                return asyncio.sleep(0, result='ok').__await__()
+
+        loop = asyncio.new_event_loop()
+        self.set_event_loop(loop)
+        task = asyncio.ensure_future(Aw(), loop=loop)
+        loop.run_until_complete(task)
+        self.assertTrue(task.done())
+        self.assertEqual(task.result(), 'ok')
+        self.assertIsInstance(task.get_coro(), types.CoroutineType)
+        loop.close()
+
     def test_ensure_future_neither(self):
         with self.assertRaises(TypeError):
             asyncio.ensure_future('ok')