Rendering complex template objects to leave non-template values alone (#29353)

tests/helpers/test_config_validation.py

@@ -395,7 +395,7 @@ def test_template_complex():
     """Test template_complex validator."""
     schema = vol.Schema(cv.template_complex)
 
-    for value in (None, "{{ partial_print }", "{% if True %}Hello"):
+    for value in ("{{ partial_print }", "{% if True %}Hello"):
         with pytest.raises(vol.MultipleInvalid):
             schema(value)
 
@@ -420,6 +420,10 @@ def test_template_complex():
         ["{{ beer }}", 1],
     )
 
+    # Ensure we don't mutate non-string types that cannot be templates.
+    for value in (1, True, None):
+        assert schema(value) == value
+
 
 def test_time_zone():
     """Test time zone validation."""