very fancy way to preserve back compatibility

scrapy/spiders/__init__.py

@@ -15,6 +15,9 @@
 from scrapy.utils.deprecate import method_is_overridden
 
 
+def __flatten(list_):
+    return (item for sublist in list_ for item in sublist)
+
 class Spider(object_ref):
     """Base class for scrapy spiders. All spiders must inherit from this
     class.
@@ -83,11 +86,8 @@ def start_requests(self):
                 yield Request(url, dont_filter=True)
 
     def start_requests_with_control(self):
-        for r in self.start_requests():
-            yield r
-
-            if r != signals.WaitUntilQueueEmpty:
-                yield signals.WaitUntilQueueEmpty
+        gen_ = ((r, signals.WaitUntilQueueEmpty) if r != signals.WaitUntilQueueEmpty else (r,) for r in self.start_requests())
+        return __flatten(gen_)
 
     def make_requests_from_url(self, url):
         """ This method is deprecated. """

tests/test_crawl.py

@@ -240,7 +240,7 @@ class TestError(Exception):
             pass
 
         class FaultySpider(SimpleSpider):
-            def start_requests_with_control(self):
+            def start_requests(self):
                 raise TestError
 
         crawler = self.runner.create_crawler(FaultySpider)