pythonGH-88050: fix race in closing subprocess pipe in asyncio (python#97951)

kumaraditya303 · lysnikolaou · commit 25c1004a8336 · 2022-10-06T11:33:12.000-07:00
Check for None when iterating over `self._pipes.values()`.
diff --git a/Lib/asyncio/base_subprocess.py b/Lib/asyncio/base_subprocess.py
@@ -216,7 +216,9 @@ def _process_exited(self, returncode):
             self._proc.returncode = returncode
         self._call(self._protocol.process_exited)
         for p in self._pipes.values():
-            p.pipe.close()
+            if p is not None:
+                p.pipe.close()
+
         self._try_finish()
 
     async def _wait(self):
