1 files changed, 20 insertions, 0 deletions
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index 231b460..e1bc98d 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -349,6 +349,26 @@ class SysModuleTest(unittest.TestCase):
         #self.assert_(r[0][1] > 100, r[0][1])
         #self.assert_(r[0][2] > 100, r[0][2])
 
+    def test_ioencoding(self):
+        import subprocess,os
+        env = dict(os.environ)
+
+        # Test character: cent sign, encoded as 0x4A (ASCII J) in CP424,
+        # not representable in ASCII.
+
+        env["PYTHONIOENCODING"] = "cp424"
+        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
+                             stdout = subprocess.PIPE, env=env)
+        out = p.stdout.read()
+        self.assertEqual(out, "\xa2\n".encode("cp424"))
+
+        env["PYTHONIOENCODING"] = "ascii:replace"
+        p = subprocess.Popen([sys.executable, "-c", 'print(chr(0xa2))'],
+                             stdout = subprocess.PIPE, env=env)
+        out = p.stdout.read().strip()
+        self.assertEqual(out, b'?')
+
+
 def test_main():
     test.support.run_unittest(SysModuleTest)