allow more operations to work on detached streams (closes #23093)

Patch by Martin Panter.

1 files changed, 14 insertions, 0 deletions

diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 2a3b4a3..ba3701a 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -654,6 +654,8 @@ class CommonBufferedTests:
         self.assertIs(buf.detach(), raw)
         self.assertRaises(ValueError, buf.detach)
 
+        repr(buf)  # Should still work
+
     def test_fileno(self):
         rawio = self.MockRawIO()
         bufio = self.tp(rawio)
@@ -1922,6 +1924,12 @@ class TextIOWrapperTest(unittest.TestCase):
         self.assertEqual(r.getvalue(), b"howdy")
         self.assertRaises(ValueError, t.detach)
 
+        # Operations independent of the detached stream should still work
+        repr(t)
+        self.assertEqual(t.encoding, "ascii")
+        self.assertEqual(t.errors, "strict")
+        self.assertFalse(t.line_buffering)
+
     def test_repr(self):
         raw = self.BytesIO("hello".encode("utf-8"))
         b = self.BufferedReader(raw)
@@ -1936,6 +1944,9 @@ class TextIOWrapperTest(unittest.TestCase):
         self.assertEqual(repr(t),
                          "<%s.TextIOWrapper name='dummy' encoding='utf-8'>" % modname)
 
+        t.buffer.detach()
+        repr(t)  # Should not raise an exception
+
     def test_line_buffering(self):
         r = self.BytesIO()
         b = self.BufferedWriter(r, 1000)
@@ -2537,6 +2548,9 @@ class CTextIOWrapperTest(TextIOWrapperTest):
         self.assertRaises(ValueError, t.__init__, b, newline='xyzzy')
         self.assertRaises(ValueError, t.read)
 
+        t = self.TextIOWrapper.__new__(self.TextIOWrapper)
+        self.assertRaises(Exception, repr, t)
+
     def test_garbage_collection(self):
         # C TextIOWrapper objects are collected, and collecting them flushes
         # all data to disk.