From 8fa9aad5e6d5bd7e664a92413b9fac32ef6e1969 Mon Sep 17 00:00:00 2001
From: Bernhard Reiter <Bernhard Reiter@git.wordpress.org>
Date: Tue, 1 Aug 2023 07:56:23 +0000
Subject: [PATCH] HTML API: Add support for SPAN element.

In this patch we're introducing support for the SPAN element, which is the first
in the class of "any other tag" in the "in body" insertion mode.

This patch introduces the mechanisms required to handle that class of tags but
only introduces SPAN to keep the change focused. With the tests and mechanisms
in place it will be possible to follow-up and add another limited set of tags.

It's important that this not use the default catch-all in the switch handling
`step_in_body` because that would catch tags that have specific rules in previous
case statements that aren't yet added. For example, we don't want to treat the
`TABLE` element as "any other tag".

Props dmsnell.
Fixes #58907.
Built from https://develop.svn.wordpress.org/trunk@56331


git-svn-id: http://core.svn.wordpress.org/trunk@55843 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 .../html-api/class-wp-html-processor.php      | 53 ++++++++++++++++++-
 wp-includes/version.php                       |  2 +-
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/wp-includes/html-api/class-wp-html-processor.php b/wp-includes/html-api/class-wp-html-processor.php
index 68bd3418f2..c8e898389c 100644
--- a/wp-includes/html-api/class-wp-html-processor.php
+++ b/wp-includes/html-api/class-wp-html-processor.php
@@ -626,6 +626,37 @@ class WP_HTML_Processor extends WP_HTML_Tag_Processor {
 				$this->insert_html_element( $this->current_token );
 				return true;
 
+			/*
+			 * > Any other start tag
+			 */
+			case '+SPAN':
+				$this->reconstruct_active_formatting_elements();
+				$this->insert_html_element( $this->current_token );
+				return true;
+
+			/*
+			 * Any other end tag
+			 */
+			case '-SPAN':
+				foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
+					// > If node is an HTML element with the same tag name as the token, then:
+					if ( $item->node_name === $tag_name ) {
+						$this->generate_implied_end_tags( $tag_name );
+
+						// > If node is not the current node, then this is a parse error.
+
+						$this->state->stack_of_open_elements->pop_until( $tag_name );
+						return true;
+					}
+
+					// > Otherwise, if node is in the special category, then this is a parse error; ignore the token, and return.
+					if ( self::is_special( $item->node_name ) ) {
+						return $this->step();
+					}
+				}
+				// Execution should not reach here; if it does then something went wrong.
+				return false;
+
 			default:
 				$this->last_error = self::ERROR_UNSUPPORTED;
 				throw new WP_HTML_Unsupported_Exception( "Cannot process {$tag_name} element." );
@@ -873,7 +904,7 @@ class WP_HTML_Processor extends WP_HTML_Tag_Processor {
 	 *
 	 * @since 6.4.0
 	 *
-	 * @throws Exception
+	 * @throws WP_HTML_Unsupported_Exception
 	 *
 	 * @see https://html.spec.whatwg.org/#generate-implied-end-tags
 	 *
@@ -893,6 +924,26 @@ class WP_HTML_Processor extends WP_HTML_Tag_Processor {
 		}
 	}
 
+	/*
+	 * Closes elements that have implied end tags, thoroughly.
+	 *
+	 * See the HTML specification for an explanation why this is
+	 * different from {@see WP_HTML_Processor::generate_implied_end_tags}.
+	 *
+	 * @since 6.4.0
+	 *
+	 * @see https://html.spec.whatwg.org/#generate-implied-end-tags
+	 */
+	private function generate_implied_end_tags_thoroughly() {
+		$elements_with_implied_end_tags = array(
+			'P',
+		);
+
+		while ( in_array( $this->state->stack_of_open_elements->current_node(), $elements_with_implied_end_tags, true ) ) {
+			$this->state->stack_of_open_elements->pop();
+		}
+	}
+
 	/**
 	 * Reconstructs the active formatting elements.
 	 *
diff --git a/wp-includes/version.php b/wp-includes/version.php
index c754fddf6a..8e0bc25952 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.4-alpha-56329';
+$wp_version = '6.4-alpha-56331';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.