From e16d9269e32d65137831443b8dc45c3c3d6b733e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Scott=20Gonz=C3=A1lez?= <scott.gonzalez@gmail.com>
Date: Mon, 2 Mar 2015 18:43:07 -0500
Subject: [PATCH] Accordion: Handle `box-sizing: border-box` in animations

Fixes #9264
Closes gh-1287
---
 ui/accordion.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/ui/accordion.js b/ui/accordion.js
index cf53e9839f7..68a4c34ec0f 100644
--- a/ui/accordion.js
+++ b/ui/accordion.js
@@ -524,6 +524,7 @@ return $.widget( "ui.accordion", {
 		var total, easing, duration,
 			that = this,
 			adjust = 0,
+			boxSizing = toShow.css( "box-sizing" ),
 			down = toShow.length &&
 				( !toHide.length || ( toShow.index() < toHide.index() ) ),
 			animate = this.options.animate || {},
@@ -566,7 +567,9 @@ return $.widget( "ui.accordion", {
 				step: function( now, fx ) {
 					fx.now = Math.round( now );
 					if ( fx.prop !== "height" ) {
-						adjust += fx.now;
+						if ( boxSizing === "content-box" ) {
+							adjust += fx.now;
+						}
 					} else if ( that.options.heightStyle !== "content" ) {
 						fx.now = Math.round( total - toHide.outerHeight() - adjust );
 						adjust = 0;