bpo-46672: fix NameError in asyncio.gather if type check fails (GH-31187) (GH-31440)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com> (cherry picked from commit 4ab8167) Co-authored-by: Nikita Sobolev <mail@sobolevn.me> Co-authored-by: Nikita Sobolev <mail@sobolevn.me>

Author: miss-islington

Lib/asyncio/tasks.py

@@ -721,7 +721,7 @@ def _done_callback(fut):
  nonlocal nfinished
  nfinished += 1
 
- if outer.done():
+ if outer is None or outer.done():
  if not fut.cancelled():
  # Mark exception retrieved.
  fut.exception()
@@ -777,6 +777,7 @@ def _done_callback(fut):
  nfuts = 0
  nfinished = 0
  loop = None
+ outer = None # bpo-46672
  for arg in coros_or_futures:
  if arg not in arg_to_fut:
  fut = _ensure_future(arg, loop=loop)

Lib/test/test_asyncio/test_tasks.py

@@ -3593,6 +3593,20 @@ async def outer():
  test_utils.run_briefly(self.one_loop)
  self.assertIsInstance(f.exception(), RuntimeError)
 
+ def test_issue46672(self):
+ with mock.patch(
+ 'asyncio.base_events.BaseEventLoop.call_exception_handler',
+ ):
+ async def coro(s):
+ return s
+ c = coro('abc')
+
+ with self.assertRaises(TypeError):
+ self._gather(c, {})
+ self._run_loop(self.one_loop)
+ # NameError should not happen:
+ self.one_loop.call_exception_handler.assert_not_called()
+
 
 class RunCoroutineThreadsafeTests(test_utils.TestCase):
  """Test case for asyncio.run_coroutine_threadsafe."""

Misc/NEWS.d/next/Library/2022-02-07-13-15-16.bpo-46672.4swIjx.rst

@@ -0,0 +1 @@
+Fix ``NameError`` in :func:`asyncio.gather` when initial type check fails.