Add test

Author: zooba

Lib/test/test_site.py

@@ -802,6 +802,15 @@ def test_underpth_dll_file(self):
             )], env=env)
         self.assertTrue(rc, "sys.path is incorrect")
 
+    @support.requires_subprocess()
+    def test_underpth_no_user_site(self):
+        pth_lines = [test.support.STDLIB_DIR, 'import site']
+        exe_file = self._create_underpth_exe(pth_lines)
+        p = subprocess.run([exe_file, '-X', 'utf8', '-c',
+                            'import sys; '
+                            'sys.exit(not sys.flags.no_user_site)'])
+        self.assertEqual(p.returncode, 0, "sys.flags.no_user_site was 0")
+
 
 if __name__ == "__main__":
     unittest.main()