diff --git a/wp-includes/class-walker-comment.php b/wp-includes/class-walker-comment.php
new file mode 100644
index 0000000000..e3f20ea453
--- /dev/null
+++ b/wp-includes/class-walker-comment.php
@@ -0,0 +1,352 @@
+ 'comment_parent', 'id' => 'comment_ID');
+
+ /**
+ * Start the list before the elements are added.
+ *
+ * @see Walker::start_lvl()
+ *
+ * @since 2.7.0
+ *
+ * @global int $comment_depth
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param int $depth Depth of comment.
+ * @param array $args Uses 'style' argument for type of HTML list.
+ */
+ public function start_lvl( &$output, $depth = 0, $args = array() ) {
+ $GLOBALS['comment_depth'] = $depth + 1;
+
+ switch ( $args['style'] ) {
+ case 'div':
+ break;
+ case 'ol':
+ $output .= '
' . "\n";
+ break;
+ case 'ul':
+ default:
+ $output .= '' . "\n";
+ break;
+ }
+ }
+
+ /**
+ * End the list of items after the elements are added.
+ *
+ * @see Walker::end_lvl()
+ *
+ * @since 2.7.0
+ *
+ * @global int $comment_depth
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param int $depth Depth of comment.
+ * @param array $args Will only append content if style argument value is 'ol' or 'ul'.
+ */
+ public function end_lvl( &$output, $depth = 0, $args = array() ) {
+ $GLOBALS['comment_depth'] = $depth + 1;
+
+ switch ( $args['style'] ) {
+ case 'div':
+ break;
+ case 'ol':
+ $output .= "
\n";
+ break;
+ case 'ul':
+ default:
+ $output .= "\n";
+ break;
+ }
+ }
+
+ /**
+ * Traverse elements to create list from elements.
+ *
+ * This function is designed to enhance Walker::display_element() to
+ * display children of higher nesting levels than selected inline on
+ * the highest depth level displayed. This prevents them being orphaned
+ * at the end of the comment list.
+ *
+ * Example: max_depth = 2, with 5 levels of nested content.
+ * 1
+ * 1.1
+ * 1.1.1
+ * 1.1.1.1
+ * 1.1.1.1.1
+ * 1.1.2
+ * 1.1.2.1
+ * 2
+ * 2.2
+ *
+ * @see Walker::display_element()
+ * @see wp_list_comments()
+ *
+ * @since 2.7.0
+ *
+ * @param object $element Data object.
+ * @param array $children_elements List of elements to continue traversing.
+ * @param int $max_depth Max depth to traverse.
+ * @param int $depth Depth of current element.
+ * @param array $args An array of arguments.
+ * @param string $output Passed by reference. Used to append additional content.
+ */
+ public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
+ if ( !$element )
+ return;
+
+ $id_field = $this->db_fields['id'];
+ $id = $element->$id_field;
+
+ parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
+
+ // If we're at the max depth, and the current element still has children, loop over those and display them at this level
+ // This is to prevent them being orphaned to the end of the list.
+ if ( $max_depth <= $depth + 1 && isset( $children_elements[$id]) ) {
+ foreach ( $children_elements[ $id ] as $child )
+ $this->display_element( $child, $children_elements, $max_depth, $depth, $args, $output );
+
+ unset( $children_elements[ $id ] );
+ }
+
+ }
+
+ /**
+ * Start the element output.
+ *
+ * @since 2.7.0
+ *
+ * @see Walker::start_el()
+ * @see wp_list_comments()
+ *
+ * @global int $comment_depth
+ * @global object $comment
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param object $comment Comment data object.
+ * @param int $depth Depth of comment in reference to parents.
+ * @param array $args An array of arguments.
+ */
+ public function start_el( &$output, $comment, $depth = 0, $args = array(), $id = 0 ) {
+ $depth++;
+ $GLOBALS['comment_depth'] = $depth;
+ $GLOBALS['comment'] = $comment;
+
+ if ( !empty( $args['callback'] ) ) {
+ ob_start();
+ call_user_func( $args['callback'], $comment, $args, $depth );
+ $output .= ob_get_clean();
+ return;
+ }
+
+ if ( ( 'pingback' == $comment->comment_type || 'trackback' == $comment->comment_type ) && $args['short_ping'] ) {
+ ob_start();
+ $this->ping( $comment, $depth, $args );
+ $output .= ob_get_clean();
+ } elseif ( 'html5' === $args['format'] ) {
+ ob_start();
+ $this->html5_comment( $comment, $depth, $args );
+ $output .= ob_get_clean();
+ } else {
+ ob_start();
+ $this->comment( $comment, $depth, $args );
+ $output .= ob_get_clean();
+ }
+ }
+
+ /**
+ * Ends the element output, if needed.
+ *
+ * @since 2.7.0
+ *
+ * @see Walker::end_el()
+ * @see wp_list_comments()
+ *
+ * @param string $output Passed by reference. Used to append additional content.
+ * @param WP_Comment $comment The comment object. Default current comment.
+ * @param int $depth Depth of comment.
+ * @param array $args An array of arguments.
+ */
+ public function end_el( &$output, $comment, $depth = 0, $args = array() ) {
+ if ( !empty( $args['end-callback'] ) ) {
+ ob_start();
+ call_user_func( $args['end-callback'], $comment, $args, $depth );
+ $output .= ob_get_clean();
+ return;
+ }
+ if ( 'div' == $args['style'] )
+ $output .= "\n";
+ else
+ $output .= "\n";
+ }
+
+ /**
+ * Output a pingback comment.
+ *
+ * @access protected
+ * @since 3.6.0
+ *
+ * @see wp_list_comments()
+ *
+ * @param WP_Comment $comment The comment object.
+ * @param int $depth Depth of comment.
+ * @param array $args An array of arguments.
+ */
+ protected function ping( $comment, $depth, $args ) {
+ $tag = ( 'div' == $args['style'] ) ? 'div' : 'li';
+?>
+ < id="comment-" >
+
+ ', '' ); ?>
+
+
+ < has_children ? 'parent' : '' ); ?> id="comment-">
+
+
+
+
+ < id="comment-" has_children ? 'parent' : '' ); ?>>
+
+
+
+
+
+ 'div-comment',
+ 'depth' => $depth,
+ 'max_depth' => $args['max_depth'],
+ 'before' => '',
+ 'after' => '
'
+ ) ) );
+ ?>
+
+ 'comment_parent', 'id' => 'comment_ID');
-
- /**
- * Start the list before the elements are added.
- *
- * @see Walker::start_lvl()
- *
- * @since 2.7.0
- *
- * @global int $comment_depth
- *
- * @param string $output Passed by reference. Used to append additional content.
- * @param int $depth Depth of comment.
- * @param array $args Uses 'style' argument for type of HTML list.
- */
- public function start_lvl( &$output, $depth = 0, $args = array() ) {
- $GLOBALS['comment_depth'] = $depth + 1;
-
- switch ( $args['style'] ) {
- case 'div':
- break;
- case 'ol':
- $output .= '' . "\n";
- break;
- case 'ul':
- default:
- $output .= '' . "\n";
- break;
- }
- }
-
- /**
- * End the list of items after the elements are added.
- *
- * @see Walker::end_lvl()
- *
- * @since 2.7.0
- *
- * @global int $comment_depth
- *
- * @param string $output Passed by reference. Used to append additional content.
- * @param int $depth Depth of comment.
- * @param array $args Will only append content if style argument value is 'ol' or 'ul'.
- */
- public function end_lvl( &$output, $depth = 0, $args = array() ) {
- $GLOBALS['comment_depth'] = $depth + 1;
-
- switch ( $args['style'] ) {
- case 'div':
- break;
- case 'ol':
- $output .= "
\n";
- break;
- case 'ul':
- default:
- $output .= "\n";
- break;
- }
- }
-
- /**
- * Traverse elements to create list from elements.
- *
- * This function is designed to enhance Walker::display_element() to
- * display children of higher nesting levels than selected inline on
- * the highest depth level displayed. This prevents them being orphaned
- * at the end of the comment list.
- *
- * Example: max_depth = 2, with 5 levels of nested content.
- * 1
- * 1.1
- * 1.1.1
- * 1.1.1.1
- * 1.1.1.1.1
- * 1.1.2
- * 1.1.2.1
- * 2
- * 2.2
- *
- * @see Walker::display_element()
- * @see wp_list_comments()
- *
- * @since 2.7.0
- *
- * @param object $element Data object.
- * @param array $children_elements List of elements to continue traversing.
- * @param int $max_depth Max depth to traverse.
- * @param int $depth Depth of current element.
- * @param array $args An array of arguments.
- * @param string $output Passed by reference. Used to append additional content.
- */
- public function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
- if ( !$element )
- return;
-
- $id_field = $this->db_fields['id'];
- $id = $element->$id_field;
-
- parent::display_element( $element, $children_elements, $max_depth, $depth, $args, $output );
-
- // If we're at the max depth, and the current element still has children, loop over those and display them at this level
- // This is to prevent them being orphaned to the end of the list.
- if ( $max_depth <= $depth + 1 && isset( $children_elements[$id]) ) {
- foreach ( $children_elements[ $id ] as $child )
- $this->display_element( $child, $children_elements, $max_depth, $depth, $args, $output );
-
- unset( $children_elements[ $id ] );
- }
-
- }
-
- /**
- * Start the element output.
- *
- * @since 2.7.0
- *
- * @see Walker::start_el()
- * @see wp_list_comments()
- *
- * @global int $comment_depth
- * @global object $comment
- *
- * @param string $output Passed by reference. Used to append additional content.
- * @param object $comment Comment data object.
- * @param int $depth Depth of comment in reference to parents.
- * @param array $args An array of arguments.
- */
- public function start_el( &$output, $comment, $depth = 0, $args = array(), $id = 0 ) {
- $depth++;
- $GLOBALS['comment_depth'] = $depth;
- $GLOBALS['comment'] = $comment;
-
- if ( !empty( $args['callback'] ) ) {
- ob_start();
- call_user_func( $args['callback'], $comment, $args, $depth );
- $output .= ob_get_clean();
- return;
- }
-
- if ( ( 'pingback' == $comment->comment_type || 'trackback' == $comment->comment_type ) && $args['short_ping'] ) {
- ob_start();
- $this->ping( $comment, $depth, $args );
- $output .= ob_get_clean();
- } elseif ( 'html5' === $args['format'] ) {
- ob_start();
- $this->html5_comment( $comment, $depth, $args );
- $output .= ob_get_clean();
- } else {
- ob_start();
- $this->comment( $comment, $depth, $args );
- $output .= ob_get_clean();
- }
- }
-
- /**
- * Ends the element output, if needed.
- *
- * @since 2.7.0
- *
- * @see Walker::end_el()
- * @see wp_list_comments()
- *
- * @param string $output Passed by reference. Used to append additional content.
- * @param WP_Comment $comment The comment object. Default current comment.
- * @param int $depth Depth of comment.
- * @param array $args An array of arguments.
- */
- public function end_el( &$output, $comment, $depth = 0, $args = array() ) {
- if ( !empty( $args['end-callback'] ) ) {
- ob_start();
- call_user_func( $args['end-callback'], $comment, $args, $depth );
- $output .= ob_get_clean();
- return;
- }
- if ( 'div' == $args['style'] )
- $output .= "\n";
- else
- $output .= "\n";
- }
-
- /**
- * Output a pingback comment.
- *
- * @access protected
- * @since 3.6.0
- *
- * @see wp_list_comments()
- *
- * @param WP_Comment $comment The comment object.
- * @param int $depth Depth of comment.
- * @param array $args An array of arguments.
- */
- protected function ping( $comment, $depth, $args ) {
- $tag = ( 'div' == $args['style'] ) ? 'div' : 'li';
-?>
- < id="comment-" >
-
- ', '' ); ?>
-
-
- < has_children ? 'parent' : '' ); ?> id="comment-">
-
-
-
-
- < id="comment-" has_children ? 'parent' : '' ); ?>>
-
-
-
-
-
- 'div-comment',
- 'depth' => $depth,
- 'max_depth' => $args['max_depth'],
- 'before' => '',
- 'after' => '
'
- ) ) );
- ?>
-
-