add test case

Author: inventshah

Lib/test/test_io/test_bufferedio.py

@@ -962,7 +962,7 @@ def test_args_error(self):
         with self.assertRaisesRegex(TypeError, "BufferedWriter"):
             self.tp(self.BytesIO(), 1024, 1024, 1024)
 
-    def test_closed_errors(self):
+    def test_non_boolean_closed_attr(self):
         # gh-140650: check TypeError is raised
         class MockRawIOWithoutClosed(self.MockRawIO):
             closed = NotImplemented
@@ -972,6 +972,17 @@ class MockRawIOWithoutClosed(self.MockRawIO):
         self.assertRaises(TypeError, bufio.flush)
         self.assertRaises(TypeError, bufio.close)
 
+    def test_closed_attr_raises(self):
+        class MockRawIOClosedRaises(self.MockRawIO):
+            @property
+            def closed(self):
+                raise ValueError("test")
+
+        bufio = self.tp(MockRawIOClosedRaises())
+        self.assertRaisesRegex(ValueError, "test", bufio.write, b"")
+        self.assertRaisesRegex(ValueError, "test", bufio.flush)
+        self.assertRaisesRegex(ValueError, "test", bufio.close)
+
 
 class PyBufferedWriterTest(BufferedWriterTest, PyTestCase):
     tp = pyio.BufferedWriter

Misc/NEWS.d/next/Library/2025-10-27-00-40-49.gh-issue-140650.DYJPJ9.rst

@@ -1,2 +1,3 @@
-Fix an issue where closing :class:`io.BufferedWriter` could crash
-if the closed attribute raised an exception.
+Fix an issue where closing :class:`io.BufferedWriter` could crash if
+the closed attribute raised an exception on access or could not be
+converted to a boolean.