From e0e266d070de8b751835f0fba2f188e93b002d96 Mon Sep 17 00:00:00 2001
From: Matt Martz <matt@sivel.net>
Date: Fri, 7 Sep 2018 10:16:03 -0500
Subject: [PATCH] [stable-2.6] Ensure loop with delegate_to can short circuit
 the same as without delegate_to. Fixes #45189 (#45231). (cherry picked from
 commit 2ac647def88a300403659a13e6ec4097baa1cdce)

Co-authored-by: Matt Martz <matt@sivel.net>
---
 .../fragments/loop_undefined_delegate_to.yaml |  4 ++++
 lib/ansible/vars/manager.py                   |  7 ++++++-
 test/integration/targets/loops/tasks/main.yml | 19 +++++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 changelogs/fragments/loop_undefined_delegate_to.yaml

diff --git a/changelogs/fragments/loop_undefined_delegate_to.yaml b/changelogs/fragments/loop_undefined_delegate_to.yaml
new file mode 100644
index 0000000000..e7e81d2b3d
--- /dev/null
+++ b/changelogs/fragments/loop_undefined_delegate_to.yaml
@@ -0,0 +1,4 @@
+bugfixes:
+- loop - Ensure that a loop with a when condition that evaluates to false and delegate_to, will short circuit if the
+  loop references an undefined variable. This matches the behavior in the same scenario without delegate_to
+  (https://github.com/ansible/ansible/issues/45189)
diff --git a/lib/ansible/vars/manager.py b/lib/ansible/vars/manager.py
index ae98e91ee0..b055f1b9f2 100644
--- a/lib/ansible/vars/manager.py
+++ b/lib/ansible/vars/manager.py
@@ -500,7 +500,12 @@ class VariableManager:
             else:
                 raise AnsibleError("Failed to find the lookup named '%s' in the available lookup plugins" % task.loop_with)
         elif task.loop is not None:
-            items = templar.template(task.loop)
+            try:
+                items = templar.template(task.loop)
+            except AnsibleUndefinedVariable:
+                # This task will be skipped later due to this, so we just setup
+                # a dummy array for the later code so it doesn't fail
+                items = [None]
         else:
             items = [None]
 
diff --git a/test/integration/targets/loops/tasks/main.yml b/test/integration/targets/loops/tasks/main.yml
index 2c83d2f0fa..2b0382d418 100644
--- a/test/integration/targets/loops/tasks/main.yml
+++ b/test/integration/targets/loops/tasks/main.yml
@@ -223,3 +223,22 @@
 - assert:
     that:
       - with_list_passed_a_dict is failed
+
+# https://github.com/ansible/ansible/issues/45189
+- name: with_X conditional delegate_to shortcircuit on templating error
+  debug:
+    msg: "loop"
+  when: false
+  delegate_to: localhost
+  with_list: "{{ fake_var }}"
+  register: result
+  failed_when: result is not skipped
+
+- name: loop conditional delegate_to shortcircuit on templating error
+  debug:
+    msg: "loop"
+  when: false
+  delegate_to: localhost
+  loop: "{{ fake_var }}"
+  register: result
+  failed_when: result is not skipped