Move test_httplib over to file context managers.

Lib/test/test_httplib.py

@@ -189,7 +189,7 @@ class BasicTest(TestCase):
         expected = (b'GET /foo HTTP/1.1\r\nHost: example.com\r\n'
                     b'Accept-Encoding: identity\r\nContent-Length:')
 
-        body = open(__file__, 'rb')
+        with open(__file__, 'rb') as body:
             conn = client.HTTPConnection('example.com')
             sock = FakeSocket(body)
             conn.sock = sock
@@ -519,10 +519,9 @@ class RequestBodyTest(TestCase):
         self.assertEqual(b'body\xc1', f.read())
 
     def test_file_body(self):
-        f = open(support.TESTFN, "w")
+        with open(support.TESTFN, "w") as f:
             f.write("body")
-        f.close()
-        f = open(support.TESTFN)
+        with open(support.TESTFN) as f:
             self.conn.request("PUT", "/url", f)
             message, f = self.get_headers_and_fp()
             self.assertEqual("text/plain", message.get_content_type())
@@ -531,10 +530,9 @@ class RequestBodyTest(TestCase):
             self.assertEqual(b'body', f.read())
 
     def test_binary_file_body(self):
-        f = open(support.TESTFN, "wb")
+        with open(support.TESTFN, "wb") as f:
             f.write(b"body\xc1")
-        f.close()
-        f = open(support.TESTFN, "rb")
+        with open(support.TESTFN, "rb") as f:
             self.conn.request("PUT", "/url", f)
             message, f = self.get_headers_and_fp()
             self.assertEqual("text/plain", message.get_content_type())