From de75b40835ecb82360321dafbd87d66db5404a4a 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
Closes gh-1459
(cherry picked from commit 4b017b414f107ed3c1dafc7601b61cbcd76acf61)
---
 ui/accordion.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/ui/accordion.js b/ui/accordion.js
index 46f7e8509..98c8412cc 100644
--- a/ui/accordion.js
+++ b/ui/accordion.js
@@ -516,6 +516,7 @@ 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 || {},
@@ -558,7 +559,9 @@ 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;