From 46c1ff8318931c52b170cccf56c4ff52fb4c1b00 Mon Sep 17 00:00:00 2001
From: "David J. Hamilton" <dhamilton@linkedin.com>
Date: Thu, 9 Mar 2017 15:10:51 -0800
Subject: [PATCH] Don't calculate `_changedKeys` pointlessly

If the internal model has no record, we won't do anything with the
changes, so let's not waste cycles calculating them.
---
 addon/-private/system/model/internal-model.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/addon/-private/system/model/internal-model.js b/addon/-private/system/model/internal-model.js
index 57553a38934..ea025758679 100644
--- a/addon/-private/system/model/internal-model.js
+++ b/addon/-private/system/model/internal-model.js
@@ -518,9 +518,15 @@ export default class InternalModel {
 
   setupData(data) {
     heimdall.increment(setupData);
-    let changedKeys = this._changedKeys(data.attributes);
+    let changedKeys;
+
+    if (this.hasRecord) {
+      changedKeys = this._changedKeys(data.attributes);
+    }
+
     assign(this._data, data.attributes);
     this.pushedData();
+
     if (this.hasRecord) {
       this.record._notifyProperties(changedKeys);
     }