1 files changed, 25 insertions, 8 deletions
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 355a33e..d5b274c 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -1929,6 +1929,15 @@ class TextIOWrapperTest(unittest.TestCase):
         self.assertRaises(TypeError, t.__init__, b, newline=42)
         self.assertRaises(ValueError, t.__init__, b, newline='xyzzy')
 
+    def test_non_text_encoding_codecs_are_rejected(self):
+        # Ensure the constructor complains if passed a codec that isn't
+        # marked as a text encoding
+        # http://bugs.python.org/issue20404
+        r = self.BytesIO()
+        b = self.BufferedWriter(r)
+        with self.assertRaisesRegex(LookupError, "is not a text encoding"):
+            self.TextIOWrapper(b, encoding="hex")
+
     def test_detach(self):
         r = self.BytesIO()
         b = self.BufferedWriter(r)
@@ -2579,15 +2588,22 @@ class TextIOWrapperTest(unittest.TestCase):
 
     def test_illegal_decoder(self):
         # Issue #17106
+        # Bypass the early encoding check added in issue 20404
+        def _make_illegal_wrapper():
+            quopri = codecs.lookup("quopri")
+            quopri._is_text_encoding = True
+            try:
+                t = self.TextIOWrapper(self.BytesIO(b'aaaaaa'),
+                                       newline='\n', encoding="quopri")
+            finally:
+                quopri._is_text_encoding = False
+            return t
         # Crash when decoder returns non-string
-        t = self.TextIOWrapper(self.BytesIO(b'aaaaaa'), newline='\n',
-                               encoding='quopri_codec')
+        t = _make_illegal_wrapper()
         self.assertRaises(TypeError, t.read, 1)
-        t = self.TextIOWrapper(self.BytesIO(b'aaaaaa'), newline='\n',
-                               encoding='quopri_codec')
+        t = _make_illegal_wrapper()
         self.assertRaises(TypeError, t.readline)
-        t = self.TextIOWrapper(self.BytesIO(b'aaaaaa'), newline='\n',
-                               encoding='quopri_codec')
+        t = _make_illegal_wrapper()
         self.assertRaises(TypeError, t.read)
 
     def _check_create_at_shutdown(self, **kwargs):
@@ -2616,8 +2632,7 @@ class TextIOWrapperTest(unittest.TestCase):
         if err:
             # Can error out with a RuntimeError if the module state
             # isn't found.
-            self.assertIn("RuntimeError: could not find io module state",
-                          err.decode())
+            self.assertIn(self.shutdown_error, err.decode())
         else:
             self.assertEqual("ok", out.decode().strip())
 
@@ -2630,6 +2645,7 @@ class TextIOWrapperTest(unittest.TestCase):
 
 class CTextIOWrapperTest(TextIOWrapperTest):
     io = io
+    shutdown_error = "RuntimeError: could not find io module state"
 
     def test_initialization(self):
         r = self.BytesIO(b"\xc3\xa9\n\n")
@@ -2674,6 +2690,7 @@ class CTextIOWrapperTest(TextIOWrapperTest):
 
 class PyTextIOWrapperTest(TextIOWrapperTest):
     io = pyio
+    shutdown_error = "LookupError: unknown encoding: ascii"
 
 
 class IncrementalNewlineDecoderTest(unittest.TestCase):