From d56e8764a1f02a214df5da1cc95191be2da2491b Mon Sep 17 00:00:00 2001
From: "jeremy@jermolene.com" <jeremy@jermolene.com>
Date: Mon, 1 Mar 2021 17:59:29 +0000
Subject: [PATCH] Button widget: apply aria-expanded attribute when controlling
 a popup

Addresses (1) and (5) from #5519
---
 core/modules/widgets/button.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/core/modules/widgets/button.js b/core/modules/widgets/button.js
index 5b15c875f..9186e1808 100644
--- a/core/modules/widgets/button.js
+++ b/core/modules/widgets/button.js
@@ -66,6 +66,9 @@ ButtonWidget.prototype.render = function(parent,nextSibling) {
 	if(this["aria-label"]) {
 		domNode.setAttribute("aria-label",this["aria-label"]);
 	}
+	if(this.popup || this.popupTitle) {
+		domNode.setAttribute("aria-expanded",isPoppedUp ? "true" : "false");
+	}
 	// Set the tabindex
 	if(this.tabIndex) {
 		domNode.setAttribute("tabindex",this.tabIndex);