Fix how "has_next_tasks" is calculated for task executions

* There was a weird typo in the list generator expression made in
  https://review.opendev.org/#/c/652575 that led to calculating
  a field value in the wrong way. Fixed. The added test was
  previously failing.

Closes-Bug: #1829841

Change-Id: I6b8ea8dfa623acbb56f649630ddee62e43d484eb

mistral/engine/tasks.py

@@ -274,7 +274,7 @@ class Task(object):
         cmds = wf_ctrl.continue_workflow(task_ex=self.task_ex)
 
         # Check whether the task generated any next tasks.
-        if any([not commands.is_engine_command(c)] for c in cmds):
+        if any([not commands.is_engine_command(c) for c in cmds]):
             self.task_ex.has_next_tasks = True
 
         # Check whether the error is handled.

mistral/tests/unit/engine/test_direct_workflow.py

@@ -1133,3 +1133,22 @@ class DirectWorkflowEngineTest(base.EngineTestCase):
             # converted into a string no matter what we tried to assign. But
             # that didn't happen on Python 2.7 which caused an SQL exception.
             self.assertIsInstance(task_ex.state_info, six.string_types)
+
+    def test_single_fail_with_next_noop(self):
+        wf_text = """---
+        version: '2.0'
+
+        wf:
+          tasks:
+            task1:
+              action: std.fail
+              on-error:
+                - noop
+        """
+
+        wf_service.create_workflows(wf_text)
+
+        # Start workflow.
+        wf_ex = self.engine.start_workflow('wf')
+
+        self.await_workflow_success(wf_ex.id)

releasenotes/notes/fix_has_next_tasks_field_calculation-5717f93d7adcd9b0.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    There was a weird typo in the list generator expression made in
+    https://review.opendev.org/#/c/652575 that led to calculating
+    a field value in the wrong way. Fixed. The added test was
+    previously failing.