perf(core): prevent iteration of arrays that should not be observable (…

…vuejs#6467) close vuejs#6284
ztlevi · Feb 14, 2018 · 0663917 · 0663917
1 parent 1c68288
commit 0663917
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/src/core/observer/index.js b/src/core/observer/index.js
@@ -157,7 +157,7 @@ export function defineReactive (
         if (childOb) {
           childOb.dep.depend()
         }
-        if (Array.isArray(value)) {
+        if (Array.isArray(value) && Object.isExtensible(value)) {
           dependArray(value)
         }
       }