diff --git a/Lib/collections.py b/Lib/collections.py
index 2f0d038..e1e9d11 100644
--- a/Lib/collections.py
+++ b/Lib/collections.py
@@ -34,7 +34,8 @@
 
     """
 
-    # Parse and validate the field names
+    # Parse and validate the field names.  Validation serves two purposes,
+    # generating informative error messages and preventing template injection attacks.
     if isinstance(field_names, str):
         field_names = field_names.replace(',', ' ').split() # names separated by whitespace and/or commas
     field_names = tuple(field_names)
@@ -129,7 +130,7 @@
         'Point class with optimized _make() and _replace() without error-checking'
         _make = classmethod(tuple.__new__)
         def _replace(self, _map=map, **kwds):
-            return self._make(_map(kwds.pop, ('x', 'y'), self))
+            return self._make(_map(kwds.get, ('x', 'y'), self))
 
     print(Point(11, 22)._replace(x=100))
 
diff --git a/Lib/decimal.py b/Lib/decimal.py
index 54e8cb4..1f5ff12 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -809,8 +809,10 @@
     def __hash__(self):
         """x.__hash__() <==> hash(x)"""
         # Decimal integers must hash the same as the ints
-        # Non-integer decimals are normalized and hashed as strings
-        # Normalization assures that hash(100E-1) == hash(10)
+        #
+        # The hash of a nonspecial noninteger Decimal must depend only
+        # on the value of that Decimal, and not on its representation.
+        # For example: hash(Decimal("100E-1")) == hash(Decimal("10")).
         if self._is_special:
             if self._isnan():
                 raise TypeError('Cannot hash a NaN value.')
@@ -826,7 +828,13 @@
             # 2**64-1.  So we can replace hash((-1)**s*c*10**e) with
             # hash((-1)**s*c*pow(10, e, 2**64-1).
             return hash((-1)**op.sign*op.int*pow(10, op.exp, 2**64-1))
-        return hash(str(self.normalize()))
+        # The value of a nonzero nonspecial Decimal instance is
+        # faithfully represented by the triple consisting of its sign,
+        # its adjusted exponent, and its coefficient with trailing
+        # zeros removed.
+        return hash((self._sign,
+                     self._exp+len(self._int),
+                     self._int.rstrip('0')))
 
     def as_tuple(self):
         """Represents the number as a triple tuple.
diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 3c64e64..0dd7f00 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -971,6 +971,23 @@
         self.assert_(hash(Decimal('Inf')))
         self.assert_(hash(Decimal('-Inf')))
 
+        # check that the value of the hash doesn't depend on the
+        # current context (issue #1757)
+        c = getcontext()
+        old_precision = c.prec
+        x = Decimal("123456789.1")
+
+        c.prec = 6
+        h1 = hash(x)
+        c.prec = 10
+        h2 = hash(x)
+        c.prec = 16
+        h3 = hash(x)
+
+        self.assertEqual(h1, h2)
+        self.assertEqual(h1, h3)
+        c.prec = old_precision
+
     def test_min_and_max_methods(self):
 
         d1 = Decimal('15.32')
diff --git a/Lib/test/test_pyexpat.py b/Lib/test/test_pyexpat.py
index cb4e6eb..9fda72d 100644
--- a/Lib/test/test_pyexpat.py
+++ b/Lib/test/test_pyexpat.py
@@ -2,6 +2,7 @@
 # handler, are obscure and unhelpful.
 
 from io import BytesIO
+import sys
 import unittest
 
 import pyexpat
@@ -385,6 +386,130 @@
 
         self.assertRaises(Exception, parser.Parse, xml)
 
+class ChardataBufferTest(unittest.TestCase):
+    """
+    test setting of chardata buffer size
+    """
+
+    def test_1025_bytes(self):
+        self.assertEquals(self.small_buffer_test(1025), 2)
+
+    def test_1000_bytes(self):
+        self.assertEquals(self.small_buffer_test(1000), 1)
+
+    def test_wrong_size(self):
+        parser = expat.ParserCreate()
+        parser.buffer_text = 1
+        def f(size):
+            parser.buffer_size = size
+
+        self.assertRaises(ValueError, f, -1)
+        self.assertRaises(ValueError, f, 0)
+
+    def test_unchanged_size(self):
+        xml1 = ("<?xml version='1.0' encoding='iso8859'?><s>%s" % ('a' * 512))
+        xml2 = 'a'*512 + '</s>'
+        parser = expat.ParserCreate()
+        parser.CharacterDataHandler = self.counting_handler
+        parser.buffer_size = 512
+        parser.buffer_text = 1
+
+        # Feed 512 bytes of character data: the handler should be called
+        # once.
+        self.n = 0
+        parser.Parse(xml1)
+        self.assertEquals(self.n, 1)
+
+        # Reassign to buffer_size, but assign the same size.
+        parser.buffer_size = parser.buffer_size
+        self.assertEquals(self.n, 1)
+
+        # Try parsing rest of the document
+        parser.Parse(xml2)
+        self.assertEquals(self.n, 2)
+
+
+    def test_disabling_buffer(self):
+        xml1 = "<?xml version='1.0' encoding='iso8859'?><a>%s" % ('a' * 512)
+        xml2 = ('b' * 1024)
+        xml3 = "%s</a>" % ('c' * 1024)
+        parser = expat.ParserCreate()
+        parser.CharacterDataHandler = self.counting_handler
+        parser.buffer_text = 1
+        parser.buffer_size = 1024
+        self.assertEquals(parser.buffer_size, 1024)
+
+        # Parse one chunk of XML
+        self.n = 0
+        parser.Parse(xml1, 0)
+        self.assertEquals(parser.buffer_size, 1024)
+        self.assertEquals(self.n, 1)
+
+        # Turn off buffering and parse the next chunk.
+        parser.buffer_text = 0
+        self.assertFalse(parser.buffer_text)
+        self.assertEquals(parser.buffer_size, 1024)
+        for i in range(10):
+            parser.Parse(xml2, 0)
+        self.assertEquals(self.n, 11)
+
+        parser.buffer_text = 1
+        self.assertTrue(parser.buffer_text)
+        self.assertEquals(parser.buffer_size, 1024)
+        parser.Parse(xml3, 1)
+        self.assertEquals(self.n, 12)
+
+
+
+    def make_document(self, bytes):
+        return ("<?xml version='1.0'?><tag>" + bytes * 'a' + '</tag>')
+
+    def counting_handler(self, text):
+        self.n += 1
+
+    def small_buffer_test(self, buffer_len):
+        xml = "<?xml version='1.0' encoding='iso8859'?><s>%s</s>" % ('a' * buffer_len)
+        parser = expat.ParserCreate()
+        parser.CharacterDataHandler = self.counting_handler
+        parser.buffer_size = 1024
+        parser.buffer_text = 1
+
+        self.n = 0
+        parser.Parse(xml)
+        return self.n
+
+    def test_change_size_1(self):
+        xml1 = "<?xml version='1.0' encoding='iso8859'?><a><s>%s" % ('a' * 1024)
+        xml2 = "aaa</s><s>%s</s></a>" % ('a' * 1025)
+        parser = expat.ParserCreate()
+        parser.CharacterDataHandler = self.counting_handler
+        parser.buffer_text = 1
+        parser.buffer_size = 1024
+        self.assertEquals(parser.buffer_size, 1024)
+
+        self.n = 0
+        parser.Parse(xml1, 0)
+        parser.buffer_size *= 2
+        self.assertEquals(parser.buffer_size, 2048)
+        parser.Parse(xml2, 1)
+        self.assertEquals(self.n, 2)
+
+    def test_change_size_2(self):
+        xml1 = "<?xml version='1.0' encoding='iso8859'?><a>a<s>%s" % ('a' * 1023)
+        xml2 = "aaa</s><s>%s</s></a>" % ('a' * 1025)
+        parser = expat.ParserCreate()
+        parser.CharacterDataHandler = self.counting_handler
+        parser.buffer_text = 1
+        parser.buffer_size = 2048
+        self.assertEquals(parser.buffer_size, 2048)
+
+        self.n=0
+        parser.Parse(xml1, 0)
+        parser.buffer_size = parser.buffer_size // 2
+        self.assertEquals(parser.buffer_size, 1024)
+        parser.Parse(xml2, 1)
+        self.assertEquals(self.n, 4)
+
 
 def test_main():
     run_unittest(SetAttributeTest,
@@ -394,7 +519,8 @@
                  BufferTextTest,
                  HandlerExceptionTest,
                  PositionTest,
-                 sf1296433Test)
+                 sf1296433Test,
+                 ChardataBufferTest)
 
 if __name__ == "__main__":
     test_main()
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index bc31620..d474206 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1133,7 +1133,7 @@
         for line in f:
             if line.startswith("tipc "):
                 return True
-    if test_support.debug:
+    if test_support.verbose:
         print("TIPC module is not loaded, please 'sudo modprobe tipc'")
     return False
 
diff --git a/Lib/test/test_winreg.py b/Lib/test/test_winreg.py
index 7b1baf8..3f73c74 100644
--- a/Lib/test/test_winreg.py
+++ b/Lib/test/test_winreg.py
@@ -73,26 +73,26 @@
 
         key = OpenKey(root_key, test_key_name)
         # Read the sub-keys
-        sub_key = OpenKey(key, subkeystr)
-        # Check I can enumerate over the values.
-        index = 0
-        while 1:
-            try:
-                data = EnumValue(sub_key, index)
-            except EnvironmentError:
-                break
-            self.assertEquals(data in test_data, True,
-                              "Didn't read back the correct test data")
-            index = index + 1
-        self.assertEquals(index, len(test_data),
-                          "Didn't read the correct number of items")
-        # Check I can directly access each item
-        for value_name, value_data, value_type in test_data:
-            read_val, read_typ = QueryValueEx(sub_key, value_name)
-            self.assertEquals(read_val, value_data,
-                              "Could not directly read the value")
-            self.assertEquals(read_typ, value_type,
-                              "Could not directly read the value")
+        with OpenKey(key, "sub_key") as sub_key:
+            # Check I can enumerate over the values.
+            index = 0
+            while 1:
+                try:
+                    data = EnumValue(sub_key, index)
+                except EnvironmentError:
+                    break
+                self.assertEquals(data in test_data, True,
+                                  "Didn't read back the correct test data")
+                index = index + 1
+            self.assertEquals(index, len(test_data),
+                              "Didn't read the correct number of items")
+            # Check I can directly access each item
+            for value_name, value_data, value_type in test_data:
+                read_val, read_typ = QueryValueEx(sub_key, value_name)
+                self.assertEquals(read_val, value_data,
+                                  "Could not directly read the value")
+                self.assertEquals(read_typ, value_type,
+                                  "Could not directly read the value")
         sub_key.Close()
         # Enumerate our main key.
         read_val = EnumKey(key, 0)
@@ -155,6 +155,11 @@
         remote_key = ConnectRegistry(self.remote_name, HKEY_CURRENT_USER)
         self.TestAll(remote_key)
 
+    def testExpandEnvironmentStrings(self):
+        r = ExpandEnvironmentStrings("%windir%\\test")
+        self.assertEqual(type(r), str)
+        self.assertEqual(r, os.environ["windir"] + "\\test")
+
 def test_main():
     test_support.run_unittest(WinregTests)