KSES: Allow the `reversed` attribute for `<ol>`.

Props lancewillett.
Fixes #35079.

git-svn-id: https://develop.svn.wordpress.org/trunk@35960 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/kses.php

@@ -398,6 +398,7 @@ if ( ! CUSTOM_TAGS ) {
 		'ol' => array(
 			'start' => true,
 			'type' => true,
+			'reversed' => true,
 		),
 		'var' => array(),
 		'video' => array(

tests/phpunit/tests/kses.php

@@ -653,4 +653,15 @@ EOF;
 
 		$this->assertEquals( $input, wp_kses( $input, $allowedposttags ) );
 	}
+
+	/**
+	 * @ticket 35079
+	 */
+	function test_ol_reversed() {
+		global $allowedposttags;
+
+		$input = '<ol reversed="reversed"><li>Item 1</li><li>Item 2</li><li>Item 3</li></ol>';
+
+		$this->assertEquals( $input, wp_kses( $input, $allowedposttags ) );
+	}
 }