Fixing bugs related to nested blocks inside roles

* Make sure dep chains are checked recursively for nested blocks
* Fixing iterator is_failed() check to make sure we're not in a
  rescue block before returning True
* Use is_failed() to test whether a host should be added to the TQM
  failed_hosts list
* Use is_failed() when compiling the list of hosts left to iterate
  over in both the linear and free strategies

Fixes #14222

lib/ansible/playbook/block.py

@@ -46,6 +46,7 @@ class Block(Base, Become, Conditional, Taggable):
         self._role         = role
         self._task_include = None
         self._parent_block = None
+        self._dep_chain    = None
         self._use_handlers = use_handlers
         self._implicit     = implicit
 
@@ -54,11 +55,6 @@ class Block(Base, Become, Conditional, Taggable):
         elif parent_block:
             self._parent_block = parent_block
 
-        if parent_block:
-            self._dep_chain = parent_block._dep_chain[:]
-        else:
-            self._dep_chain = []
-
         super(Block, self).__init__()
 
     def get_vars(self):
@@ -153,6 +149,15 @@ class Block(Base, Become, Conditional, Taggable):
         except AssertionError:
             raise AnsibleParserError("A malformed block was encountered.", obj=self._ds)
 
+    def get_dep_chain(self):
+        if self._dep_chain is None:
+            if self._parent_block:
+                return self._parent_block.get_dep_chain()
+            else:
+                return None
+        else:
+            return self._dep_chain[:]
+
     def copy(self, exclude_parent=False, exclude_tasks=False):
         def _dupe_task_list(task_list, new_block):
             new_task_list = []
@@ -169,7 +174,9 @@ class Block(Base, Become, Conditional, Taggable):
         new_me = super(Block, self).copy()
         new_me._play         = self._play
         new_me._use_handlers = self._use_handlers
-        new_me._dep_chain    = self._dep_chain[:]
+
+        if self._dep_chain:
+            new_me._dep_chain = self._dep_chain[:]
 
         if not exclude_tasks:
             new_me.block  = _dupe_task_list(self.block or [], new_me)
@@ -201,7 +208,7 @@ class Block(Base, Become, Conditional, Taggable):
             if attr not in ('block', 'rescue', 'always'):
                 data[attr] = getattr(self, attr)
 
-        data['dep_chain'] = self._dep_chain
+        data['dep_chain'] = self.get_dep_chain()
 
         if self._role is not None:
             data['role'] = self._role.serialize()
@@ -226,7 +233,7 @@ class Block(Base, Become, Conditional, Taggable):
             if attr in data and attr not in ('block', 'rescue', 'always'):
                 setattr(self, attr, data.get(attr))
 
-        self._dep_chain = data.get('dep_chain', [])
+        self._dep_chain = data.get('dep_chain', None)
 
         # if there was a serialized role, unpack it too
         role_data = data.get('role')
@@ -247,10 +254,12 @@ class Block(Base, Become, Conditional, Taggable):
             pb = Block()
             pb.deserialize(pb_data)
             self._parent_block = pb
+            self._dep_chain = self._parent_block.get_dep_chain()
 
     def evaluate_conditional(self, templar, all_vars):
-        if len(self._dep_chain):
-            for dep in self._dep_chain:
+        dep_chain = self.get_dep_chain()
+        if dep_chain:
+            for dep in dep_chain:
                 if not dep.evaluate_conditional(templar, all_vars):
                     return False
         if self._task_include is not None:
@@ -274,8 +283,10 @@ class Block(Base, Become, Conditional, Taggable):
         if self._task_include:
             self._task_include.set_loader(loader)
 
-        for dep in self._dep_chain:
-            dep.set_loader(loader)
+        dep_chain = self.get_dep_chain()
+        if dep_chain:
+            for dep in dep_chain:
+                dep.set_loader(loader)
 
     def _get_parent_attribute(self, attr, extend=False):
         '''
@@ -305,10 +316,10 @@ class Block(Base, Become, Conditional, Taggable):
                 else:
                     value = parent_value
 
-                if len(self._dep_chain) and (value is None or extend):
-                    reverse_dep_chain = self._dep_chain[:]
-                    reverse_dep_chain.reverse()
-                    for dep in reverse_dep_chain:
+                dep_chain = self.get_dep_chain()
+                if dep_chain and (value is None or extend):
+                    dep_chain.reverse()
+                    for dep in dep_chain:
                         dep_value = getattr(dep, attr, None)
                         if extend:
                             value = self._extend_value(value, dep_value)

lib/ansible/playbook/role/__init__.py

@@ -262,10 +262,11 @@ class Role(Base, Become, Conditional, Taggable):
     def get_inherited_vars(self, dep_chain=[], include_params=True):
         inherited_vars = dict()
 
-        for parent in dep_chain:
-            inherited_vars = combine_vars(inherited_vars, parent._role_vars)
-            if include_params:
-                inherited_vars = combine_vars(inherited_vars, parent._role_params)
+        if dep_chain:
+            for parent in dep_chain:
+                inherited_vars = combine_vars(inherited_vars, parent._role_vars)
+                if include_params:
+                    inherited_vars = combine_vars(inherited_vars, parent._role_params)
         return inherited_vars
 
     def get_role_params(self):