Index: Lib/test/test_httplib.py
===================================================================
--- Lib/test/test_httplib.py	(revision 73751)
+++ Lib/test/test_httplib.py	(working copy)
@@ -72,7 +72,26 @@
                     headers[header] = str(len(body))
                 conn.request('POST', '/', body, headers)
                 self.assertEqual(conn._buffer.count[header.lower()], 1)
+    def test_v6host_header(self):
+        # Default host header on IPv6 transaction should wrapped by [] if 
+        # its actual IPv6 address
+        expected = 'GET /foo HTTP/1.1\r\nHost: [2001::]:81\r\n' \
+                   'Accept-Encoding: identity\r\n\r\n'
+        conn = httplib.HTTPConnection('[2001::]:81')
+        sock = FakeSocket('')
+        conn.sock = sock
+        conn.request('GET', '/foo')
+        self.assertTrue(sock.data.startswith(expected))
 
+        expected = 'GET /foo HTTP/1.1\r\nHost: [2001:102A::]\r\n' \
+                   'Accept-Encoding: identity\r\n\r\n'
+        conn = httplib.HTTPConnection('[2001:102A::]')
+        sock = FakeSocket('')
+        conn.sock = sock
+        conn.request('GET', '/foo')
+        self.assertTrue(sock.data.startswith(expected))
+      
+
 class BasicTest(TestCase):
     def test_status_lines(self):
         # Test HTTP status lines