[3.12] gh-105987: Fix reference counting issue in `_asyncio._swap_cur… (#106099)

[3.12] gh-105987: Fix reference counting issue in `_asyncio._swap_current_task` (GH-105989).
(cherry picked from commit d2cbb6e918d9ea39f0dd44acb53270f2dac07454)

Co-authored-by: chgnrdv <52372310+chgnrdv@users.noreply.github.com>

1 files changed, 18 insertions, 1 deletions

diff --git a/Lib/test/test_asyncio/test_eager_task_factory.py b/Lib/test/test_asyncio/test_eager_task_factory.py
index fe69093..3468887 100644
--- a/Lib/test/test_asyncio/test_eager_task_factory.py
+++ b/Lib/test/test_asyncio/test_eager_task_factory.py
@@ -12,7 +12,7 @@ from asyncio import base_events
 from asyncio import tasks
 from test.test_asyncio import utils as test_utils
 from test.test_asyncio.test_tasks import get_innermost_context
-from test import support
+from test.support.script_helper import assert_python_ok
 
 MOCK_ANY = mock.ANY
 
@@ -228,6 +228,23 @@ class PyEagerTaskFactoryLoopTests(EagerTaskFactoryLoopTests, test_utils.TestCase
 class CEagerTaskFactoryLoopTests(EagerTaskFactoryLoopTests, test_utils.TestCase):
     Task = getattr(tasks, '_CTask', None)
 
+    def test_issue105987(self):
+        code = """if 1:
+        from _asyncio import _swap_current_task
+
+        class DummyTask:
+            pass
+
+        class DummyLoop:
+            pass
+
+        l = DummyLoop()
+        _swap_current_task(l, DummyTask())
+        t = _swap_current_task(l, None)
+        """
+
+        _, out, err = assert_python_ok("-c", code)
+        self.assertFalse(err)
 
 class AsyncTaskCounter:
     def __init__(self, loop, *, task_class, eager):