From f15f7484bb2265ae46b227c9ddb2300958e93e3f Mon Sep 17 00:00:00 2001
From: Yury Selivanov <yselivanov@sprymix.com>
Date: Mon, 14 Apr 2014 22:21:52 -0400
Subject: [PATCH 1/2] asyncio.tasks: Fix CoroWrapper to workaround yield-from
 bug in CPython < 3.4.1

Closes issue #21209.
---
 Lib/asyncio/tasks.py                |  5 ++++-
 Lib/test/test_asyncio/test_tasks.py | 25 +++++++++++++++++++++++++
 Misc/NEWS                           |  3 +++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/Lib/asyncio/tasks.py b/Lib/asyncio/tasks.py
index 153f731a76d..0366da35fee 100644
--- a/Lib/asyncio/tasks.py
+++ b/Lib/asyncio/tasks.py
@@ -49,7 +49,10 @@ class CoroWrapper:
     def __next__(self):
         return next(self.gen)
 
-    def send(self, value):
+    def send(self, *value):
+        # We use `*value` because of a bug in CPythons prior
+        # to 3.4.1. See issue #21209 and test_yield_from_corowrapper
+        # for details.  This workaround should be removed in 3.5.0.
         return self.gen.send(value)
 
     def throw(self, exc):
diff --git a/Lib/test/test_asyncio/test_tasks.py b/Lib/test/test_asyncio/test_tasks.py
index ced34312f79..45de8acc1a3 100644
--- a/Lib/test/test_asyncio/test_tasks.py
+++ b/Lib/test/test_asyncio/test_tasks.py
@@ -1386,6 +1386,31 @@ class TaskTests(unittest.TestCase):
         self.assertRaises(ValueError, self.loop.run_until_complete,
             asyncio.wait([], loop=self.loop))
 
+    def test_yield_from_corowrapper(self):
+        old_debug = asyncio.tasks._DEBUG
+        asyncio.tasks._DEBUG = True
+        try:
+            @asyncio.coroutine
+            def t1():
+                return (yield from t2())
+
+            @asyncio.coroutine
+            def t2():
+                f = asyncio.Future(loop=self.loop)
+                asyncio.Task(t3(f), loop=self.loop)
+                return (yield from f)
+
+            @asyncio.coroutine
+            def t3(f):
+                f.set_result((1, 2, 3))
+
+            task = asyncio.Task(t1(), loop=self.loop)
+            val = self.loop.run_until_complete(task)
+            self.assertEqual(val, (1, 2, 3))
+        finally:
+            asyncio.tasks._DEBUG = old_debug
+
+
 class GatherTestsBase:
 
     def setUp(self):
diff --git a/Misc/NEWS b/Misc/NEWS
index 8519b6196ce..9cdc6059c15 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -147,6 +147,9 @@ Library
   positional-or-keyword arguments passed as keyword arguments become
   keyword-only.
 
+- Issue #21209: Fix asyncio.tasks.CoroWrapper to workaround a bug
+  in yield-from implementation in CPythons prior to 3.4.1.
+
 IDLE
 ----
 

From 9417764e0164711886ee5416204b59ec47ef54c7 Mon Sep 17 00:00:00 2001
From: Yury Selivanov <yselivanov@sprymix.com>
Date: Mon, 14 Apr 2014 22:22:36 -0400
Subject: [PATCH 2/2] misc.news: Remove whitespace

---
 Misc/NEWS | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Misc/NEWS b/Misc/NEWS
index 9cdc6059c15..45401d6cd8a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -30,7 +30,7 @@ Core and Builtins
 - Issue #12546: Allow \x00 to be used as a fill character when using str, int,
   float, and complex __format__ methods.
 
-- Issue #13598: Modify string.Formatter to support auto-numbering of 
+- Issue #13598: Modify string.Formatter to support auto-numbering of
   replacement fields. It now matches the behavior of str.format() in
   this regard. Patches by Phil Elson and Ramchandra Apte.