diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index f28a483570c..d41930163a3 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -499,16 +499,30 @@ class GeneralModuleTests(unittest.TestCase):
         from socket import inet_aton as f, inet_pton, AF_INET
         g = lambda a: inet_pton(AF_INET, a)
 
+        assertInvalid = lambda func,a: self.assertRaises(
+            (socket.error, ValueError), func, a
+        )
+
         self.assertEqual(b'\x00\x00\x00\x00', f('0.0.0.0'))
         self.assertEqual(b'\xff\x00\xff\x00', f('255.0.255.0'))
         self.assertEqual(b'\xaa\xaa\xaa\xaa', f('170.170.170.170'))
         self.assertEqual(b'\x01\x02\x03\x04', f('1.2.3.4'))
         self.assertEqual(b'\xff\xff\xff\xff', f('255.255.255.255'))
+        assertInvalid(f, '0.0.0.')
+        assertInvalid(f, '300.0.0.0')
+        assertInvalid(f, 'a.0.0.0')
+        assertInvalid(f, '1.2.3.4.5')
+        assertInvalid(f, '::1')
 
         self.assertEqual(b'\x00\x00\x00\x00', g('0.0.0.0'))
         self.assertEqual(b'\xff\x00\xff\x00', g('255.0.255.0'))
         self.assertEqual(b'\xaa\xaa\xaa\xaa', g('170.170.170.170'))
         self.assertEqual(b'\xff\xff\xff\xff', g('255.255.255.255'))
+        assertInvalid(g, '0.0.0.')
+        assertInvalid(g, '300.0.0.0')
+        assertInvalid(g, 'a.0.0.0')
+        assertInvalid(g, '1.2.3.4.5')
+        assertInvalid(g, '::1')
 
     def testIPv6toString(self):
         if not hasattr(socket, 'inet_pton'):
@@ -520,6 +534,9 @@ class GeneralModuleTests(unittest.TestCase):
         except ImportError:
             return
         f = lambda a: inet_pton(AF_INET6, a)
+        assertInvalid = lambda a: self.assertRaises(
+            (socket.error, ValueError), f, a
+        )
 
         self.assertEqual(b'\x00' * 16, f('::'))
         self.assertEqual(b'\x00' * 16, f('0::0'))
@@ -528,21 +545,62 @@ class GeneralModuleTests(unittest.TestCase):
             b'\x45\xef\x76\xcb\x00\x1a\x56\xef\xaf\xeb\x0b\xac\x19\x24\xae\xae',
             f('45ef:76cb:1a:56ef:afeb:bac:1924:aeae')
         )
+        self.assertEqual(
+            b'\xad\x42\x0a\xbc' + b'\x00' * 4 + b'\x01\x27\x00\x00\x02\x54\x00\x02',
+            f('ad42:abc::127:0:254:2')
+        )
+        self.assertEqual(b'\x00\x12\x00\x0a' + b'\x00' * 12, f('12:a::'))
+        assertInvalid('0x20::')
+        assertInvalid(':::')
+        assertInvalid('::0::')
+        assertInvalid('1::abc::')
+        assertInvalid('1::abc::def')
+        assertInvalid('1:2:3:4:5:6:')
+        assertInvalid('1:2:3:4:5:6')
+        assertInvalid('1:2:3:4:5:6:7:8:')
+        assertInvalid('1:2:3:4:5:6:7:8:0')
+
+        self.assertEqual(b'\x00' * 12 + b'\xfe\x2a\x17\x40',
+            f('::254.42.23.64')
+        )
+        self.assertEqual(
+            b'\x00\x42' + b'\x00' * 8 + b'\xa2\x9b\xfe\x2a\x17\x40',
+            f('42::a29b:254.42.23.64')
+        )
+        self.assertEqual(
+            b'\x00\x42\xa8\xb9\x00\x00\x00\x02\xff\xff\xa2\x9b\xfe\x2a\x17\x40',
+            f('42:a8b9:0:2:ffff:a29b:254.42.23.64')
+        )
+        assertInvalid('255.254.253.252')
+        assertInvalid('1::260.2.3.0')
+        assertInvalid('1::0.be.e.0')
+        assertInvalid('1:2:3:4:5:6:7:1.2.3.4')
+        assertInvalid('::1.2.3.4:0')
+        assertInvalid('0.100.200.0:3:4:5:6:7:8')
 
     def testStringToIPv4(self):
         if not hasattr(socket, 'inet_ntop'):
             return # No inet_ntop() on this platform
         from socket import inet_ntoa as f, inet_ntop, AF_INET
         g = lambda a: inet_ntop(AF_INET, a)
+        assertInvalid = lambda func,a: self.assertRaises(
+            (socket.error, ValueError), func, a
+        )
 
         self.assertEqual('1.0.1.0', f(b'\x01\x00\x01\x00'))
         self.assertEqual('170.85.170.85', f(b'\xaa\x55\xaa\x55'))
         self.assertEqual('255.255.255.255', f(b'\xff\xff\xff\xff'))
         self.assertEqual('1.2.3.4', f(b'\x01\x02\x03\x04'))
+        assertInvalid(f, b'\x00' * 3)
+        assertInvalid(f, b'\x00' * 5)
+        assertInvalid(f, b'\x00' * 16)
 
         self.assertEqual('1.0.1.0', g(b'\x01\x00\x01\x00'))
         self.assertEqual('170.85.170.85', g(b'\xaa\x55\xaa\x55'))
         self.assertEqual('255.255.255.255', g(b'\xff\xff\xff\xff'))
+        assertInvalid(g, b'\x00' * 3)
+        assertInvalid(g, b'\x00' * 5)
+        assertInvalid(g, b'\x00' * 16)
 
     def testStringToIPv6(self):
         if not hasattr(socket, 'inet_ntop'):
@@ -554,6 +612,9 @@ class GeneralModuleTests(unittest.TestCase):
         except ImportError:
             return
         f = lambda a: inet_ntop(AF_INET6, a)
+        assertInvalid = lambda a: self.assertRaises(
+            (socket.error, ValueError), f, a
+        )
 
         self.assertEqual('::', f(b'\x00' * 16))
         self.assertEqual('::1', f(b'\x00' * 15 + b'\x01'))
@@ -562,6 +623,10 @@ class GeneralModuleTests(unittest.TestCase):
             f(b'\x0a\xef\x0b\x01\x05\x06\x10\x01\xff\xff\x99\x97\x00\x55\x01\x70')
         )
 
+        assertInvalid(b'\x12' * 15)
+        assertInvalid(b'\x12' * 17)
+        assertInvalid(b'\x12' * 4)
+
     # XXX The following don't test module-level functionality...
 
     def testSockName(self):
diff --git a/Misc/ACKS b/Misc/ACKS
index 86c78abde8c..ef21b7f4579 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -353,6 +353,7 @@ Michael Guravage
 Lars Gustäbel
 Thomas Güttler
 Barry Haddow
+Philipp Hagemeister
 Paul ten Hagen
 Rasmus Hahn
 Peter Haight