#17163: merge with 3.3.

diff --cc Lib/test/test_file.py
index d5eca2bb77f1e1039bbe976bcb1e23cd7298e6a5,a78ddf3d3cabfb6a4ba161728c67f2336af5d4bc..1daffe4712bcccf49cbcb473744e674c2aa222f3
--- 1/Lib/test/test_file.py
--- 2/Lib/test/test_file.py
+++ b/Lib/test/test_file.py
@@@ -126,12 -126,12 +126,12 @@@ class AutoFileTests
              self.assertEqual(self.f.__exit__(*sys.exc_info()), None)
  
      def testReadWhenWriting(self):
 -        self.assertRaises(IOError, self.f.read)
 +        self.assertRaises(OSError, self.f.read)
  
- class CAutoFileTests(AutoFileTests):
+ class CAutoFileTests(AutoFileTests, unittest.TestCase):
      open = io.open
  
- class PyAutoFileTests(AutoFileTests):
+ class PyAutoFileTests(AutoFileTests, unittest.TestCase):
      open = staticmethod(pyio.open)
  
  

diff --cc Misc/NEWS
index 909375a82e785edbfaaa28f270378da59fa2d8a5,616ce65822ad29226f227a8d74a2a021cd2aeb06..f4ac978f0a1b677f7066108afc35450926dbedc1
--- 1/Misc/NEWS
--- 2/Misc/NEWS
+++ b/Misc/NEWS
@@@ -839,8 -605,9 +839,11 @@@ Test
  
  - Issue #15539: Added regression tests for Tools/scripts/pindent.py.
  
 +- Issue #16836: Enable IPv6 support even if IPv6 is disabled on the build host.
 +
+ - Issue #17163: test_file now works with unittest test discovery.
+   Patch by Zachary Ware.
+ 
  - Issue #16925: test_configparser now works with unittest test discovery.
    Patch by Zachary Ware.