Merge 3.5 (test_socket, issue #25138)

Lib/test/test_socket.py

@@ -1289,12 +1289,11 @@ class GeneralModuleTests(unittest.TestCase):
     @unittest.skipUnless(support.is_resource_enabled('network'),
                          'network is not enabled')
     def test_idna(self):
-        # Check for internet access before running test (issue #12804).
-        try:
+        # Check for internet access before running test
+        # (issue #12804, issue #25138).
+        with support.transient_internet('python.org'):
             socket.gethostbyname('python.org')
-        except socket.gaierror as e:
-            if e.errno == socket.EAI_NODATA:
-                self.skipTest('internet access required for this test')
+
         # these should all be successful
         domain = 'испытание.pythontest.net'
         socket.gethostbyname(domain)