test that pools can't be created with size==0

greentest/test__pool.py

@@ -153,6 +153,10 @@ class PoolBasicTests(greentest.TestCase):
         result = p.apply(lambda a: ('foo', a), (1, ))
         self.assertEqual(result, ('foo', 1))
 
+    def test_init_zerosize(self):
+        self.switch_expected = False
+        self.assertRaises(ValueError, self.klass, 0)
+        
 #
 # tests from standard library test/test_multiprocessing.py