Hash collision security issue

Lib/test/test_cmd_line.py

 # Tests invocation of the interpreter with various command line arguments
 # All tests are executed with environment variables ignored
 # See test_cmd_line_script.py for testing of script execution
 
 import os
 import test.support, unittest
-import os
 import sys
 import subprocess
 
 def _spawn_python(*args):
     cmd_line = [sys.executable]
     # When testing -S, we need PYTHONPATH to work (see test_site_flag())
     if '-S' not in args:
         cmd_line.append('-E')
     cmd_line.extend(args)
     return subprocess.Popen(cmd_line, stdin=subprocess.PIPE,
@@ skipping 165 matching lines @@
 path = path.encode("ascii", "backslashreplace")
 sys.stdout.buffer.write(path)"""
             code = code.strip().splitlines()
             code = '; '.join(code)
             p = _spawn_python('-S', '-c', code)
             stdout, _ = p.communicate()
             p.stdout.close()
             self.assertTrue(path1.encode('ascii') in stdout)
             self.assertTrue(path2.encode('ascii') in stdout)
 
+    def test_hash_randomization(self):
+        # Verify that -R enables hash randomization:
+        self.verify_valid_flag('-R')
+        hashes = []
+        for i in range(2):
+            code = 'print(hash("spam"))'
+            data, rc = self.start_python_and_exit_code('-R', '-c', code)
+            self.assertEqual(rc, 0)
+            hashes.append(data)
+        self.assertNotEqual(hashes[0], hashes[1])
+
+        # Verify that sys.flags contains hash_randomization
+        code = 'import sys; print("random is", sys.flags.hash_randomization)'
+        data, rc = self.start_python_and_exit_code('-R', '-c', code)
+        self.assertEqual(rc, 0)
+        self.assertIn(b'random is 1', data)
 
 def test_main():
     test.support.run_unittest(CmdLineTest)
     test.support.reap_children()
 
 if __name__ == "__main__":
     test_main()