diff --git a/Lib/gettext.py b/Lib/gettext.py
index d62ac07..4c957c0 100644
--- a/Lib/gettext.py
+++ b/Lib/gettext.py
@@ -415,7 +415,6 @@
         if fallback:
             return NullTranslations()
         raise IOError(ENOENT, 'No translation file found for domain', domain)
-    # TBD: do we need to worry about the file pointer getting collected?
     # Avoid opening, reading, and parsing the .mo file after it's been done
     # once.
     result = None
@@ -423,7 +422,8 @@
         key = os.path.abspath(mofile)
         t = _translations.get(key)
         if t is None:
-            t = _translations.setdefault(key, class_(open(mofile, 'rb')))
+            with open(mofile, 'rb') as fp:
+                t = _translations.setdefault(key, class_(fp))
         # Copy the translation object to allow setting fallbacks and
         # output charset. All other instance data is shared with the
         # cached object.
diff --git a/Lib/idlelib/macosxSupport.py b/Lib/idlelib/macosxSupport.py
index b23221e..b794a83 100644
--- a/Lib/idlelib/macosxSupport.py
+++ b/Lib/idlelib/macosxSupport.py
@@ -88,6 +88,7 @@
         # on an EditorWindow instance that is then passed as the first
         # argument to ConfigDialog)
         root.instance_dict = flist.inversedict
+        root.instance_dict = flist.inversedict
         configDialog.ConfigDialog(root, 'Settings')
 
 
diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 517a7a9..9780c83 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -720,8 +720,12 @@
         """
         if raiseExceptions:
             ei = sys.exc_info()
-            traceback.print_exception(ei[0], ei[1], ei[2], None, sys.stderr)
-            del ei
+            try:
+                traceback.print_exception(ei[0], ei[1], ei[2], None, sys.stderr)
+            except IOError:
+                pass    # see issue 5971
+            finally:
+                del ei
 
 class StreamHandler(Handler):
     """
diff --git a/Lib/test/support.py b/Lib/test/support.py
index df114a2..b91d732 100644
--- a/Lib/test/support.py
+++ b/Lib/test/support.py
@@ -5,6 +5,7 @@
 
 import contextlib
 import errno
+import functools
 import socket
 import sys
 import os
@@ -933,6 +934,16 @@
         count += 1
         time.sleep(0.1)
 
+def reap_threads(func):
+    @functools.wraps(func)
+    def decorator(*args):
+        key = threading_setup()
+        try:
+            return func(*args)
+        finally:
+            threading_cleanup(*key)
+    return decorator
+
 def reap_children():
     """Use this function at the end of test_main() whenever sub-processes
     are started.  This will help ensure that no extra children (zombies)
diff --git a/Lib/test/test_hashlib.py b/Lib/test/test_hashlib.py
index 594f5dd..5bfea6b 100644
--- a/Lib/test/test_hashlib.py
+++ b/Lib/test/test_hashlib.py
@@ -267,10 +267,9 @@
 
         self.assertEqual(expected_hash, hasher.hexdigest())
 
-
+@support.reap_threads
 def test_main():
     support.run_unittest(HashLibTestCase)
 
-
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index c680d8d..0600cfc 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -35,9 +35,7 @@
                 retries += 1
                 if retries > 10:
                     # XXX test skipped
-                    print("couldn't allocate two consecutive fds, "
-                        "skipping test_closerange", file=sys.stderr)
-                    return
+                    self.skipTest("couldn't allocate two consecutive fds")
                 first, second = second, os.dup(second)
         finally:
             os.close(second)
diff --git a/Lib/test/test_unittest.py b/Lib/test/test_unittest.py
index ea33180..858f24b 100644
--- a/Lib/test/test_unittest.py
+++ b/Lib/test/test_unittest.py
@@ -3175,7 +3175,7 @@
 
         result = MockResult()
         test = TestableTest('testNothing')
-        test._result = result
+        test._resultForDoCleanups = result
 
         exc1 = Exception('foo')
         exc2 = Exception('bar')
diff --git a/Lib/unittest.py b/Lib/unittest.py
index cdccd8c..9c3024a 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -353,7 +353,7 @@
            not have a method with the specified name.
         """
         self._testMethodName = methodName
-        self._result = None
+        self._resultForDoCleanups = None
         try:
             testMethod = getattr(self, methodName)
         except AttributeError:
@@ -457,7 +457,7 @@
             if startTestRun is not None:
                 startTestRun()
 
-        self._result = result
+        self._resultForDoCleanups = result
         result.startTest(self)
         if getattr(self.__class__, "__unittest_skip__", False):
             # If the whole class was skipped.
@@ -511,7 +511,7 @@
     def doCleanups(self):
         """Execute all cleanup functions. Normally called for you after
         tearDown."""
-        result = self._result
+        result = self._resultForDoCleanups
         ok = True
         while self._cleanups:
             function, args, kwargs = self._cleanups.pop(-1)
@@ -732,23 +732,32 @@
             if seq1 == seq2:
                 return
 
+            seq1_repr = repr(seq1)
+            seq2_repr = repr(seq2)
+            if len(seq1_repr) > 30:
+                seq1_repr = seq1_repr[:30] + '...'
+            if len(seq2_repr) > 30:
+                seq2_repr = seq2_repr[:30] + '...'
+            elements = (seq_type_name.capitalize(), seq1_repr, seq2_repr)
+            differing = '%ss differ: %s != %s\n' % elements
+
             for i in range(min(len1, len2)):
                 try:
                     item1 = seq1[i]
                 except (TypeError, IndexError, NotImplementedError):
-                    differing = ('Unable to index element %d of first %s\n' %
+                    differing += ('\nUnable to index element %d of first %s\n' %
                                  (i, seq_type_name))
                     break
 
                 try:
                     item2 = seq2[i]
                 except (TypeError, IndexError, NotImplementedError):
-                    differing = ('Unable to index element %d of second %s\n' %
+                    differing += ('\nUnable to index element %d of second %s\n' %
                                  (i, seq_type_name))
                     break
 
                 if item1 != item2:
-                    differing = ('First differing element %d:\n%s\n%s\n' %
+                    differing += ('\nFirst differing element %d:\n%s\n%s\n' %
                                  (i, item1, item2))
                     break
             else:
@@ -756,28 +765,26 @@
                     type(seq1) != type(seq2)):
                     # The sequences are the same, but have differing types.
                     return
-                # A catch-all message for handling arbitrary user-defined
-                # sequences.
-                differing = '%ss differ:\n' % seq_type_name.capitalize()
-                if len1 > len2:
-                    differing = ('First %s contains %d additional '
-                                 'elements.\n' % (seq_type_name, len1 - len2))
-                    try:
-                        differing += ('First extra element %d:\n%s\n' %
-                                      (len2, seq1[len2]))
-                    except (TypeError, IndexError, NotImplementedError):
-                        differing += ('Unable to index element %d '
-                                      'of first %s\n' % (len2, seq_type_name))
-                elif len1 < len2:
-                    differing = ('Second %s contains %d additional '
-                                 'elements.\n' % (seq_type_name, len2 - len1))
-                    try:
-                        differing += ('First extra element %d:\n%s\n' %
-                                      (len1, seq2[len1]))
-                    except (TypeError, IndexError, NotImplementedError):
-                        differing += ('Unable to index element %d '
-                                      'of second %s\n' % (len1, seq_type_name))
-        standardMsg = differing + '\n'.join(difflib.ndiff(pprint.pformat(seq1).splitlines(),
+
+            if len1 > len2:
+                differing += ('\nFirst %s contains %d additional '
+                             'elements.\n' % (seq_type_name, len1 - len2))
+                try:
+                    differing += ('First extra element %d:\n%s\n' %
+                                  (len2, seq1[len2]))
+                except (TypeError, IndexError, NotImplementedError):
+                    differing += ('Unable to index element %d '
+                                  'of first %s\n' % (len2, seq_type_name))
+            elif len1 < len2:
+                differing += ('\nSecond %s contains %d additional '
+                             'elements.\n' % (seq_type_name, len2 - len1))
+                try:
+                    differing += ('First extra element %d:\n%s\n' %
+                                  (len1, seq2[len1]))
+                except (TypeError, IndexError, NotImplementedError):
+                    differing += ('Unable to index element %d '
+                                  'of second %s\n' % (len1, seq_type_name))
+        standardMsg = differing + '\n' + '\n'.join(difflib.ndiff(pprint.pformat(seq1).splitlines(),
                                             pprint.pformat(seq2).splitlines()))
         msg = self._formatMessage(msg, standardMsg)
         self.fail(msg)
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index 5f2efb9..5f24187 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -1055,28 +1055,27 @@
             self.fp.write(zinfo.FileHeader())
             return
 
-        fp = io.open(filename, "rb")
-        # Must overwrite CRC and sizes with correct data later
-        zinfo.CRC = CRC = 0
-        zinfo.compress_size = compress_size = 0
-        zinfo.file_size = file_size = 0
-        self.fp.write(zinfo.FileHeader())
-        if zinfo.compress_type == ZIP_DEFLATED:
-            cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
-                 zlib.DEFLATED, -15)
-        else:
-            cmpr = None
-        while 1:
-            buf = fp.read(1024 * 8)
-            if not buf:
-                break
-            file_size = file_size + len(buf)
-            CRC = crc32(buf, CRC) & 0xffffffff
-            if cmpr:
-                buf = cmpr.compress(buf)
-                compress_size = compress_size + len(buf)
-            self.fp.write(buf)
-        fp.close()
+        with open(filename, "rb") as fp:
+            # Must overwrite CRC and sizes with correct data later
+            zinfo.CRC = CRC = 0
+            zinfo.compress_size = compress_size = 0
+            zinfo.file_size = file_size = 0
+            self.fp.write(zinfo.FileHeader())
+            if zinfo.compress_type == ZIP_DEFLATED:
+                cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
+                     zlib.DEFLATED, -15)
+            else:
+                cmpr = None
+            while 1:
+                buf = fp.read(1024 * 8)
+                if not buf:
+                    break
+                file_size = file_size + len(buf)
+                CRC = crc32(buf, CRC) & 0xffffffff
+                if cmpr:
+                    buf = cmpr.compress(buf)
+                    compress_size = compress_size + len(buf)
+                self.fp.write(buf)
         if cmpr:
             buf = cmpr.flush()
             compress_size = compress_size + len(buf)
@@ -1400,9 +1399,8 @@
             tgtdir = os.path.dirname(tgt)
             if not os.path.exists(tgtdir):
                 os.makedirs(tgtdir)
-            fp = io.open(tgt, 'wb')
-            fp.write(zf.read(path))
-            fp.close()
+            with open(tgt, 'wb') as fp:
+                fp.write(zf.read(path))
         zf.close()
 
     elif args[0] == '-c':