add subprocess test

Author: benjimin

tests/cloudpickle_test.py

@@ -403,5 +403,26 @@ def example():
         f = cloudpickle.loads(s)
         f() # test
 
+    def test_multiprocess(self):
+        # running a function pickled by another process
+        def scope():
+            import curses.textpad
+            def example():
+                x = xml.etree.ElementTree.Comment
+                x = curses.textpad.Textbox
+            return example
+        global xml
+        import xml.etree.ElementTree
+        example = scope()
+
+        s = cloudpickle.dumps(example)
+
+        import subprocess
+        # no point trying "import multiprocessing" because that library
+        # uses fork to preserve the loaded environment.
+        assert not subprocess.call(['python', '-c',
+                                    'import pickle; (pickle.loads(' +
+                                    s.__str__() + '))()'])
+
 if __name__ == '__main__':
     unittest.main()