test__queue.py: add test for issue #45: join() blocks on empty queue

greentest/test__queue.py

@@ -320,5 +320,14 @@ class TestNoWait(TestCase):
         assert q.empty(), q
 
 
+class TestJoinEmpty(TestCase):
+
+    def test_issue_45(self):
+        """Test that join() exits immediatelly if not jobs were put into the queue"""
+        self.switch_expected = False
+        q = queue.JoinableQueue()
+        q.join()
+
+
 if __name__ == '__main__':
     main()