Comments: Escape permalink values on edit screen to prevent XSS.

There doesn't appear to be any way for an attacker to introduce malicious input into the URL, unless a plugin is filtering the URL to add it, but it's better to be safe than sorry.

Props 1naveengiri, joyously.
Merges [43290] to the 4.9 branch.
Fixes #44115.
Built from https://develop.svn.wordpress.org/branches/4.9@43301


git-svn-id: http://core.svn.wordpress.org/branches/4.9@43130 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/edit-form-comment.php

@@ -29,7 +29,11 @@ if ( 'approved' === wp_get_comment_status( $comment ) && $comment->comment_post_
 <div class="inside">
 	<div id="comment-link-box">
 		<strong><?php _ex( 'Permalink:', 'comment' ); ?></strong>
-		<span id="sample-permalink"><a href="<?php echo $comment_link; ?>"><?php echo $comment_link; ?></a></span>
+		<span id="sample-permalink">
+			<a href="<?php echo esc_url( $comment_link ); ?>">
+				<?php echo esc_html( $comment_link ); ?>
+			</a>
+		</span>
 	</div>
 </div>
 <?php endif; ?>

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9.7-alpha-43300';
+$wp_version = '4.9.7-alpha-43301';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.