Fix nested noop block padding in dynamic includes (ansible#38814)

* Fix nested noop block padding in dynamic includes

* Address issues from the review

* Fix typo

lib/ansible/plugins/strategy/linear.py

@@ -31,7 +31,7 @@
     author: Ansible Core Team
 '''
 
-from ansible.errors import AnsibleError
+from ansible.errors import AnsibleError, AnsibleAssertionError
 from ansible.executor.play_iterator import PlayIterator
 from ansible.module_utils.six import iteritems
 from ansible.module_utils._text import to_text
@@ -52,6 +52,36 @@
 
 class StrategyModule(StrategyBase):
 
+    noop_task = None
+
+    def _replace_with_noop(self, target):
+        if self.noop_task is None:
+            raise AnsibleAssertionError('strategy.linear.StrategyModule.noop_task is None, need Task()')
+
+        result = []
+        for el in target:
+            if isinstance(el, Task):
+                result.append(self.noop_task)
+            elif isinstance(el, Block):
+                result.append(self._create_noop_block_from(el, el._parent))
+        return result
+
+    def _create_noop_block_from(self, original_block, parent):
+        noop_block = Block(parent_block=parent)
+        noop_block.block = self._replace_with_noop(original_block.block)
+        noop_block.always = self._replace_with_noop(original_block.always)
+        noop_block.rescue = self._replace_with_noop(original_block.rescue)
+
+        return noop_block
+
+    def _prepare_and_create_noop_block_from(self, original_block, parent, iterator):
+        self.noop_task = Task()
+        self.noop_task.action = 'meta'
+        self.noop_task.args['_raw_params'] = 'noop'
+        self.noop_task.set_loader(iterator._play._loader)
+
+        return self._create_noop_block_from(original_block, parent)
+
     def _get_next_task_lockstep(self, hosts, iterator):
         '''
         Returns a list of (host, task) tuples, where the task may
@@ -309,12 +339,6 @@ def run(self, iterator, play_context):
                 if len(included_files) > 0:
                     display.debug("we have included files to process")
 
-                    # A noop task for use in padding dynamic includes
-                    noop_task = Task()
-                    noop_task.action = 'meta'
-                    noop_task.args['_raw_params'] = 'noop'
-                    noop_task.set_loader(iterator._play._loader)
-
                     display.debug("generating all_blocks data")
                     all_blocks = dict((host, []) for host in hosts_left)
                     display.debug("done generating all_blocks data")
@@ -345,10 +369,7 @@ def run(self, iterator, play_context):
                                 final_block = new_block.filter_tagged_tasks(play_context, task_vars)
                                 display.debug("done filtering new block on tags")
 
-                                noop_block = Block(parent_block=task._parent)
-                                noop_block.block = [noop_task for t in new_block.block]
-                                noop_block.always = [noop_task for t in new_block.always]
-                                noop_block.rescue = [noop_task for t in new_block.rescue]
+                                noop_block = self._prepare_and_create_noop_block_from(final_block, task._parent, iterator)
 
                                 for host in hosts_left:
                                     if host in included_file._hosts:

test/integration/targets/strategy_linear/aliases

@@ -0,0 +1 @@
+posix/ci/group3

test/integration/targets/strategy_linear/roles/role1/tasks/main.yml

@@ -0,0 +1,6 @@
+- name: Include tasks
+  include_tasks: "tasks.yml"
+
+- name: Mark role as finished
+  set_fact:
+    role1_complete: True

test/integration/targets/strategy_linear/roles/role1/tasks/tasks.yml

@@ -0,0 +1,7 @@
+- name: Call role2
+  include_role:
+    name: role2
+
+- name: Call role2 again
+  include_role:
+    name: role2

test/integration/targets/strategy_linear/roles/role2/tasks/main.yml

@@ -0,0 +1,7 @@
+- block:
+    - block:
+      - name: Nested task 1
+        debug: msg="Nested task 1"
+
+      - name: Nested task 2
+        debug: msg="Nested task 2"

test/integration/targets/strategy_linear/runme.sh

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+set -eux
+
+ansible-playbook test_include_file_noop.yml -i ../../inventory "$@"

test/integration/targets/strategy_linear/test_include_file_noop.yml

@@ -0,0 +1,16 @@
+- hosts:
+    - testhost
+    - testhost2
+  gather_facts: no
+  vars:
+    secondhost: testhost2
+  tasks:
+    - name: Call the first role only on one host
+      include_role:
+        name: role1
+      when: inventory_hostname is match(secondhost)
+
+    - name: Make sure nothing else runs until role1 finishes
+      assert:
+        that:
+          - "'role1_complete' in hostvars[secondhost]"