Canvas: Fixes another res.parent problem

celery/canvas.py

@@ -747,6 +747,7 @@ class chain(Signature):
                 )
                 prev_res = prev_prev_res
 
+
             if is_last_task:
                 # chain(task_id=id) means task id is set for the last task
                 # in the chain.  If the chord is part of a chord/group
@@ -770,13 +771,14 @@ class chain(Signature):
                     task.link(prev_task)
 
                 if prev_res:
-                    if prev_res.parent:
+                    if isinstance(prev_task, chord):
                         # If previous task was a chord,
                         # the freeze above would have set a parent for
                         # us, but we'd be overwriting it here.
 
                         # so fix this relationship so it's:
                         #     chord body -> group -> THIS RES
+                        assert isinstance(prev_res.parent, GroupResult)
                         prev_res.parent.parent = res
                     else:
                         prev_res.parent = res
@@ -1235,9 +1237,11 @@ class chord(Signature):
         #   XXX chord is also a class in outer scope.
         if not isinstance(self.tasks, group):
             self.tasks = group(self.tasks, app=self.app)
-        bodyres = self.body.freeze(_id, parent_id=self.id, root_id=root_id)
-        bodyres.parent = self.tasks.freeze(
+        header_result = self.tasks.freeze(
             parent_id=parent_id, root_id=root_id, chord=self.body)
+        bodyres = self.body.freeze(
+            _id, parent_id=header_result.id, root_id=root_id)
+        bodyres.parent = header_result
         self.id = self.tasks.id
         self.body.set_parent_id(self.id)
         return bodyres
@@ -1291,7 +1295,7 @@ class chord(Signature):
             countdown=1, max_retries=None, eager=False,
             task_id=None, **options):
         app = app or self._get_app(body)
-        group_id = uuid()
+        group_id = header.options.get('task_id') or uuid()
         root_id = body.options.get('root_id')
         body.chord_size = self.__length_hint__()
         options = dict(self.options, **options) if options else self.options
@@ -1301,6 +1305,7 @@ class chord(Signature):
 
         results = header.freeze(
             group_id=group_id, chord=body, root_id=root_id).results
+        body.set_parent_id(group_id)
         bodyres = body.freeze(task_id, root_id=root_id)
 
         parent = app.backend.apply_chord(

t/unit/tasks/test_canvas.py

@@ -19,7 +19,7 @@ from celery.canvas import (
     maybe_unroll_group,
     _seq_concat_seq,
 )
-from celery.result import EagerResult
+from celery.result import AsyncResult, GroupResult, EagerResult
 
 SIG = Signature({
     'task': 'TASK',
@@ -492,6 +492,30 @@ class test_chain(CanvasCase):
         assert x.tasks[0].type, self.add
         assert x.type
 
+    def test_chord_sets_result_parent(self):
+        g = (self.add.s(0, 0) |
+             group(self.add.s(i, i) for i in range(1, 10)) |
+             self.add.s(2, 2) |
+             self.add.s(4, 4))
+        res = g.freeze()
+
+        assert isinstance(res, AsyncResult)
+        assert not isinstance(res, GroupResult)
+        assert isinstance(res.parent, AsyncResult)
+        assert not isinstance(res.parent, GroupResult)
+        assert isinstance(res.parent.parent, GroupResult)
+        assert isinstance(res.parent.parent.parent, AsyncResult)
+        assert not isinstance(res.parent.parent.parent, GroupResult)
+        assert res.parent.parent.parent.parent is None
+
+        seen = set()
+        node = res
+        while node:
+            assert node.id not in seen
+            seen.add(node.id)
+            node = node.parent
+
+
 
 class test_group(CanvasCase):