propagate the original CancelledError

Author: deadlovelll

Lib/asyncio/taskgroups.py

@@ -116,13 +116,15 @@ async def _aexit(self, et, exc):
         # can be cancelled multiple times if our parent task
         # is being cancelled repeatedly (or even once, when
         # our own cancellation is already in progress)
+        pending_cancellation_error = None
         while self._tasks:
             if self._on_completed_fut is None:
                 self._on_completed_fut = self._loop.create_future()
 
             try:
                 await self._on_completed_fut
             except exceptions.CancelledError as ex:
+                pending_cancellation_error = ex
                 if not self._aborting:
                     # Our parent task is being cancelled:
                     #
@@ -151,9 +153,9 @@ async def _aexit(self, et, exc):
                 # If there are no pending cancellations left,
                 # don't propagate CancelledError.
                 propagate_cancellation_error = None
-            else:
+            elif propagate_cancellation_error is None:
                 # gh-155433: the remaining cancellation is not ours, don't drop it
-                propagate_cancellation_error = exceptions.CancelledError()
+                propagate_cancellation_error = pending_cancellation_error
 
         # Propagate CancelledError if there is one, except if there
         # are other errors -- those have priority.