From ec6ef6d8b37c1501924b50f6f26974e26e900e9f Mon Sep 17 00:00:00 2001
From: Alexey <lesha.ogonkov@gmail.com>
Date: Sun, 29 Mar 2020 23:12:55 +0300
Subject: [PATCH] Iterate only own properties

---
 nunjucks/src/lib.js | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/nunjucks/src/lib.js b/nunjucks/src/lib.js
index 6fda6eae..dec92068 100644
--- a/nunjucks/src/lib.js
+++ b/nunjucks/src/lib.js
@@ -196,6 +196,13 @@ function getAttrGetter(attribute, postprocess, defaultValue) {
   return function attrGetter(item) {
     let _item = item;
 
+    function rollback() {
+      _item = undefined;
+      if (defaultValue) {
+        _item = defaultValue;
+      }
+    }
+
     for (let i = 0; i < parts.length; i++) {
       const part = parts[i];
 
@@ -203,12 +210,15 @@ function getAttrGetter(attribute, postprocess, defaultValue) {
       // that something goes wrong. Just roll out to undefined or default value
       // in that case.
       try {
-        _item = _item[part];
-      } catch (e) {
-        _item = undefined;
-        if (defaultValue) {
-          _item = defaultValue;
+        if (hasOwnProp(_item, part)) {
+          _item = _item[part];
+        } else {
+          rollback();
+
+          break;
         }
+      } catch (e) {
+        rollback();
 
         break;
       }