Editor: A11y: Set ARIA attributes for Classic Editor link inserter.

Set `aria-modal` and `aria-hidden` attributes when the Classic Editor link inserter modal is active, so that content behind the modal will be properly treated as inert when interacting with the modal.

Props lyonmuller, jwgoedert, sabernhardt, alexstine, afercia, rajinsharwar, rcreators, audrasjb, hmbashar, joedolson.
Fixes #60799.

git-svn-id: https://develop.svn.wordpress.org/trunk@58450 602fd350-edb4-49c9-b593-d223f7449a82

src/js/_enqueues/lib/link.js

@@ -105,6 +105,7 @@
 			var ed,
 				$body = $( document.body );
 
+			$( '#wpwrap' ).attr( 'aria-hidden', 'true' );
 			$body.addClass( 'modal-open' );
 			wpLink.modalOpen = true;
 
@@ -281,6 +282,7 @@
 
 		close: function( reset ) {
 			$( document.body ).removeClass( 'modal-open' );
+			$( '#wpwrap' ).removeAttr( 'aria-hidden' );
 			wpLink.modalOpen = false;
 
 			if ( reset !== 'noReset' ) {

src/wp-includes/class-wp-editor.php

@@ -1875,7 +1875,7 @@ public static function wp_link_dialog() {
 		// `display: none` is required here, see #WP27605.
 		?>
 		<div id="wp-link-backdrop" style="display: none"></div>
-		<div id="wp-link-wrap" class="wp-core-ui" style="display: none" role="dialog" aria-labelledby="link-modal-title">
+		<div id="wp-link-wrap" class="wp-core-ui" style="display: none" role="dialog" aria-modal="true" aria-labelledby="link-modal-title">
 		<form id="wp-link" tabindex="-1">
 		<?php wp_nonce_field( 'internal-linking', '_ajax_linking_nonce', false ); ?>
 		<h1 id="link-modal-title"><?php _e( 'Insert/edit link' ); ?></h1>