Normalize how None is handled in quote filter. Fixes #32174 (#71473)

changelogs/fragments/32174-normalize-None-quote.yml

@@ -0,0 +1,3 @@
+bugfixes:
+- quote filter - normalize how ``None`` is handled, to match Python3 behavior
+  (https://github.com/ansible/ansible/issues/32174)

lib/ansible/plugins/filter/core.py

@@ -110,6 +110,8 @@ def strftime(string_format, second=None):
 
 def quote(a):
     ''' return its argument quoted for shell usage '''
+    if a is None:
+        a = u''
     return shlex_quote(to_text(a))
 
 

test/integration/targets/filter_core/tasks/main.yml

@@ -601,3 +601,10 @@
       bar: 123
     thing_items: '{{ thing_dict.items() }}'
     thing_range: '{{ range(10) }}'
+
+- name: Assert that quote works on None
+  assert:
+    that:
+      - thing|quote == "''"
+  vars:
+    thing: null