Issue #23353, asyncio: Workaround CPython bug #23353

Don't use yield/yield-from in an except block of a generator. Store the
exception and handle it outside the except block.

1 files changed, 9 insertions, 2 deletions

diff --git a/Lib/asyncio/windows_events.py b/Lib/asyncio/windows_events.py
index c4bffc4..f311e46 100644
--- a/Lib/asyncio/windows_events.py
+++ b/Lib/asyncio/windows_events.py
@@ -373,10 +373,17 @@ class ProactorEventLoop(proactor_events.BaseProactorEventLoop):
                                              **kwargs)
         try:
             yield from waiter
-        except:
+        except Exception as exc:
+            # Workaround CPython bug #23353: using yield/yield-from in an
+            # except block of a generator doesn't clear properly sys.exc_info()
+            err = exc
+        else:
+            err = None
+
+        if err is not None:
             transp.close()
             yield from transp._wait()
-            raise
+            raise err
 
         return transp