diff -r 48c4eec2b7e6 -r 8c2e4d02f4ef wp/wp-includes/html-api/class-wp-html-active-formatting-elements.php --- a/wp/wp-includes/html-api/class-wp-html-active-formatting-elements.php Fri Sep 05 18:40:08 2025 +0200 +++ b/wp/wp-includes/html-api/class-wp-html-active-formatting-elements.php Fri Sep 05 18:52:52 2025 +0200 @@ -51,7 +51,7 @@ * @param WP_HTML_Token $token Look for this node in the stack. * @return bool Whether the referenced node is in the stack of active formatting elements. */ - public function contains_node( $token ) { + public function contains_node( WP_HTML_Token $token ) { foreach ( $this->walk_up() as $item ) { if ( $token->bookmark_name === $item->bookmark_name ) { return true; @@ -87,6 +87,22 @@ } /** + * Inserts a "marker" at the end of the list of active formatting elements. + * + * > The markers are inserted when entering applet, object, marquee, + * > template, td, th, and caption elements, and are used to prevent + * > formatting from "leaking" into applet, object, marquee, template, + * > td, th, and caption elements. + * + * @see https://html.spec.whatwg.org/#concept-parser-marker + * + * @since 6.7.0 + */ + public function insert_marker(): void { + $this->push( new WP_HTML_Token( null, 'marker', false ) ); + } + + /** * Pushes a node onto the stack of active formatting elements. * * @since 6.4.0 @@ -95,7 +111,7 @@ * * @param WP_HTML_Token $token Push this node onto the stack. */ - public function push( $token ) { + public function push( WP_HTML_Token $token ) { /* * > If there are already three elements in the list of active formatting elements after the last marker, * > if any, or anywhere in the list if there are no markers, that have the same tag name, namespace, and @@ -119,7 +135,7 @@ * @param WP_HTML_Token $token Remove this node from the stack, if it's there already. * @return bool Whether the node was found and removed from the stack of active formatting elements. */ - public function remove_node( $token ) { + public function remove_node( WP_HTML_Token $token ) { foreach ( $this->walk_up() as $position_from_end => $item ) { if ( $token->bookmark_name !== $item->bookmark_name ) { continue; @@ -184,4 +200,30 @@ yield $this->stack[ $i ]; } } + + /** + * Clears the list of active formatting elements up to the last marker. + * + * > When the steps below require the UA to clear the list of active formatting elements up to + * > the last marker, the UA must perform the following steps: + * > + * > 1. Let entry be the last (most recently added) entry in the list of active + * > formatting elements. + * > 2. Remove entry from the list of active formatting elements. + * > 3. If entry was a marker, then stop the algorithm at this point. + * > The list has been cleared up to the last marker. + * > 4. Go to step 1. + * + * @see https://html.spec.whatwg.org/multipage/parsing.html#clear-the-list-of-active-formatting-elements-up-to-the-last-marker + * + * @since 6.7.0 + */ + public function clear_up_to_last_marker(): void { + foreach ( $this->walk_up() as $item ) { + array_pop( $this->stack ); + if ( 'marker' === $item->node_name ) { + break; + } + } + } }