asyncio: wait_for() now accepts None as timeout (Victor Stinner).

Lib/asyncio/tasks.py

@@ -394,6 +394,9 @@ def wait_for(fut, timeout, *, loop=None):
     if loop is None:
         loop = events.get_event_loop()
 
+    if timeout is None:
+        return (yield from fut)
+
     waiter = futures.Future(loop=loop)
     timeout_handle = loop.call_later(timeout, _release_waiter, waiter, False)
     cb = functools.partial(_release_waiter, waiter, True)

Lib/test/test_asyncio/test_tasks.py

@@ -380,6 +380,17 @@ class TaskTests(unittest.TestCase):
         self.assertEqual(foo_running, False)
 
 
+    def test_wait_for_blocking(self):
+        loop = test_utils.TestLoop()
+        self.addCleanup(loop.close)
+
+        @asyncio.coroutine
+        def coro():
+            return 'done'
+
+        res = loop.run_until_complete(asyncio.wait_for(coro(), timeout=None, loop=loop))
+        self.assertEqual(res, 'done')
+
     def test_wait_for_with_global_loop(self):
 
         def gen():