From 6547d7ffcb19eafe4ef4799e59dc8fe66558efaa Mon Sep 17 00:00:00 2001
From: Andrew Duthie <andrew@andrewduthie.com>
Date: Wed, 3 May 2017 17:23:29 -0400
Subject: [PATCH] Unset keys when concatenating child elements

---
 element/index.js      | 6 +++---
 element/test/index.js | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/element/index.js b/element/index.js
index 8c8b2762a88755..056aec1c31a043 100644
--- a/element/index.js
+++ b/element/index.js
@@ -77,11 +77,11 @@ export function renderToString( element ) {
  * @return {Array}                The concatenated value
  */
 export function concatChildren( ...childrens ) {
-	return childrens.reduce( ( memo, children, i ) => {
-		Children.forEach( children, ( child, j ) => {
+	return childrens.reduce( ( memo, children ) => {
+		Children.forEach( children, ( child ) => {
 			if ( child && 'string' !== typeof child ) {
 				child = cloneElement( child, {
-					key: [ i, j ].join()
+					key: undefined
 				} );
 			}
 
diff --git a/element/test/index.js b/element/test/index.js
index 842ac6a0465e16..981869e5da7edb 100644
--- a/element/test/index.js
+++ b/element/test/index.js
@@ -45,14 +45,14 @@ describe( 'element', () => {
 			expect( concatChildren( [ 'a' ], 'b' ) ).to.eql( [ 'a', 'b' ] );
 		} );
 
-		it( 'should concat the object arrays and rewrite keys', () => {
+		it( 'should concat the object arrays and unset keys', () => {
 			const concat = concatChildren(
 				[ createElement( 'strong', {}, 'Courgette' ) ],
 				createElement( 'strong', {}, 'Concombre' )
 			);
 			expect( concat.length ).to.equal( 2 );
-			expect( concat[ 0 ].key ).to.equal( '0,0' );
-			expect( concat[ 1 ].key ).to.equal( '1,0' );
+			expect( concat[ 0 ].key ).to.be.null();
+			expect( concat[ 1 ].key ).to.be.null();
 		} );
 	} );
 } );