Merge tests from 3.5

Lib/test/test_sysconfig.py

@@ -5,7 +5,8 @@ import subprocess
 import shutil
 from copy import copy
 
-from test.support import (run_unittest, TESTFN, unlink, check_warnings,
+from test.support import (run_unittest,
+                          import_module, TESTFN, unlink, check_warnings,
                           captured_stdout, skip_unless_symlink, change_cwd)
 
 import sysconfig
@@ -389,7 +390,8 @@ class TestSysConfig(unittest.TestCase):
                          hasattr(sys.implementation, '_multiarch'),
                          'multiarch-specific test')
     def test_triplet_in_ext_suffix(self):
-        import ctypes, platform, re
+        ctypes = import_module('ctypes')
+        import platform, re
         machine = platform.machine()
         suffix = sysconfig.get_config_var('EXT_SUFFIX')
         if re.match('(aarch64|arm|mips|ppc|powerpc|s390|sparc)', machine):

Lib/test/test_unicode.py

@@ -465,6 +465,13 @@ class UnicodeTest(string_tests.CommonTest,
         self.checkraises(TypeError, ' ', 'join', [1, 2, 3])
         self.checkraises(TypeError, ' ', 'join', ['1', '2', 3])
 
+    @unittest.skipIf(sys.maxsize > 2**32,
+        'needs too much memory on a 64-bit platform')
+    def test_join_overflow(self):
+        size = int(sys.maxsize**0.5) + 1
+        seq = ('A' * size,) * size
+        self.assertRaises(OverflowError, ''.join, seq)
+
     def test_replace(self):
         string_tests.CommonTest.test_replace(self)