jinja: correct member access rule (#18905)

tests/test-jinja.cpp

@@ -1063,6 +1063,18 @@ static void test_object_methods(testing & t) {
         {{"obj", {{"items", json::array({1, 2, 3})}}}},
         "{\"items\": [1, 2, 3]}"
     );
+
+    test_template(t, "object attribute and key access",
+        "{{ obj.keys()|join(',') }} vs {{ obj['keys'] }} vs {{ obj.test }}",
+        {{"obj", {{"keys", "value"}, {"test", "attr_value"}}}},
+        "keys,test vs value vs attr_value"
+    );
+
+    test_template(t, "env should not have object methods",
+        "{{ keys is undefined }} {{ obj.keys is defined }}",
+        {{"obj", {{"a", "b"}}}},
+        "True True"
+    );
 }
 
 static void test_template(testing & t, const std::string & name, const std::string & tmpl, const json & vars, const std::string & expect) {