chain: must accept generator argument (regression). Closes #1319

celery/canvas.py

@@ -267,7 +267,8 @@ class Signature(dict):
 class chain(Signature):
 
     def __init__(self, *tasks, **options):
-        tasks = tasks[0] if len(tasks) == 1 and is_list(tasks[0]) else tasks
+        tasks = (regen(tasks[0]) if len(tasks) == 1 and is_list(tasks[0])
+                else tasks)
         Signature.__init__(
             self, 'celery.chain', (), {'tasks': tasks}, **options
         )

celery/tests/tasks/test_canvas.py

@@ -134,6 +134,11 @@ class test_chain(Case):
         self.assertEqual(res.parent.parent.get(), 8)
         self.assertIsNone(res.parent.parent.parent)
 
+    def test_accepts_generator_argument(self):
+        x = chain(add.s(i) for i in range(10))
+        self.assertTrue(x.tasks[0].type, add)
+        self.assertTrue(x.type)
+
 
 class test_group(Case):