2.12: Keep pre Python 3.10 literal_eval behavior (#76261)

changelogs/fragments/jinja2_native-literal_eval-py310.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - jinja2_native - keep same behavior on Python 3.10.

lib/ansible/playbook/conditional.py

@@ -184,12 +184,7 @@ def generic_visit(self, node, inside_call=False, inside_yield=False):
             # NOTE The spaces around True and False are intentional to short-circuit safe_eval and avoid
             #      its expensive calls.
             presented = "{%% if %s %%} True {%% else %%} False {%% endif %%}" % conditional
-            # NOTE Convert the result to text to account for both native and non-native jinja.
-            # NOTE The templated result of `presented` is string on native jinja as well prior to Python 3.10.
-            #      ast.literal_eval on Python 3.10 removes leading whitespaces so " True " becomes bool True
-            #      as opposed to Python 3.9 and lower where the same would result in IndentationError and
-            #      string " True " would be returned by Templar.
-            val = to_text(templar.template(presented, disable_lookups=disable_lookups)).strip()
+            val = templar.template(presented, disable_lookups=disable_lookups).strip()
             if val == "True":
                 return True
             elif val == "False":

lib/ansible/template/native_helpers.py

@@ -6,9 +6,9 @@
 __metaclass__ = type
 
 
-from ast import literal_eval
-from itertools import islice, chain
+import ast
 import types
+from itertools import islice, chain
 
 from jinja2.runtime import StrictUndefined
 
@@ -83,7 +83,11 @@ def ansible_native_concat(nodes):
         out = u''.join([to_text(_fail_on_undefined(v)) for v in nodes])
 
     try:
-        out = literal_eval(out)
-        return out
+        return ast.literal_eval(
+            # In Python 3.10+ ast.literal_eval removes leading spaces/tabs
+            # from the given string. For backwards compatibility we need to
+            # parse the string ourselves without removing leading spaces/tabs.
+            ast.parse(out, mode='eval')
+        )
     except (ValueError, SyntaxError, MemoryError):
         return out