From: Evan You <yyx990803@gmail.com>
Date: Mon, 28 Oct 2019 00:45:54 +0000 (-0400)
Subject: chore: comment on cloneVNode implementation [ci skip]
X-Git-Tag: v3.0.0-alpha.0~295
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a8aa3289078de09f27527c374b602d63ff6c0738;p=thirdparty%2Fvuejs%2Fcore.git

chore: comment on cloneVNode implementation [ci skip]
---

diff --git a/packages/runtime-core/src/vnode.ts b/packages/runtime-core/src/vnode.ts
index 3293315c17..98cdc0211f 100644
--- a/packages/runtime-core/src/vnode.ts
+++ b/packages/runtime-core/src/vnode.ts
@@ -233,6 +233,8 @@ export function createVNode(
 }
 
 export function cloneVNode(vnode: VNode, extraProps?: Data): VNode {
+  // This is intentionally NOT using spread or extend to avoid the runtime
+  // key enumeration cost.
   return {
     _isVNode: true,
     type: vnode.type,