asyncio: Prevent StopIteration from being thrown into a Future
Patch by Chris Angelico (issue #26221)
diff --git a/Lib/asyncio/futures.py b/Lib/asyncio/futures.py
index 281fea3..ddb9cde 100644
--- a/Lib/asyncio/futures.py
+++ b/Lib/asyncio/futures.py
@@ -341,6 +341,9 @@
raise InvalidStateError('{}: {!r}'.format(self._state, self))
if isinstance(exception, type):
exception = exception()
+ if type(exception) is StopIteration:
+ raise TypeError("StopIteration interacts badly with generators "
+ "and cannot be raised into a Future")
self._exception = exception
self._state = _FINISHED
self._schedule_callbacks()