[3.12] gh-122332: Fix missing NULL check in asyncio.Task.get_coro (GH-122338) (#122345)

gh-122332: Fix missing `NULL` check in `asyncio.Task.get_coro` (GH-122338)
(cherry picked from commit c086962)

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>

Author: miss-islington

Lib/test/test_asyncio/test_eager_task_factory.py

@@ -246,6 +246,18 @@ class DummyLoop:
         _, out, err = assert_python_ok("-c", code)
         self.assertFalse(err)
 
+    def test_issue122332(self):
+       async def coro():
+           pass
+
+       async def run():
+           task = self.loop.create_task(coro())
+           await task
+           self.assertIsNone(task.get_coro())
+
+       self.run_coro(run())
+
+
 class AsyncTaskCounter:
     def __init__(self, loop, *, task_class, eager):
         self.suspense_count = 0

Misc/NEWS.d/next/Library/2024-07-26-21-21-13.gh-issue-122332.fvw88r.rst

@@ -0,0 +1,2 @@
+Fixed segfault with :meth:`asyncio.Task.get_coro` when using an eager task
+factory.

Modules/_asynciomodule.c

@@ -2509,7 +2509,11 @@ static PyObject *
 _asyncio_Task_get_coro_impl(TaskObj *self)
 /*[clinic end generated code: output=bcac27c8cc6c8073 input=d2e8606c42a7b403]*/
 {
-    return Py_NewRef(self->task_coro);
+    if (self->task_coro) {
+        return Py_NewRef(self->task_coro);
+    }
+
+    Py_RETURN_NONE;
 }
 
 /*[clinic input]