From 0fafa44a20af0af865849ae52141340ab92868bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bartosz=20Dziewo=C5=84ski?= <dziewonski@fastmail.fm>
Date: Thu, 20 Jun 2024 22:34:38 +0200
Subject: [PATCH] ExtractFormatter: Rescue headings from being removed

Bug: T363445
Change-Id: I662fe3dd06d6b010108c6f0ef891a8c6113b9a45
---
 includes/ExtractFormatter.php          | 15 ++++++++++++++-
 tests/phpunit/ExtractFormatterTest.php | 11 +++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/includes/ExtractFormatter.php b/includes/ExtractFormatter.php
index 1cde6f7..f755ae4 100644
--- a/includes/ExtractFormatter.php
+++ b/includes/ExtractFormatter.php
@@ -4,6 +4,7 @@ namespace TextExtracts;
 
 use DOMElement;
 use HtmlFormatter\HtmlFormatter;
+use Wikimedia\Parsoid\Utils\DOMCompat;
 
 /**
  * Provides text-only or limited-HTML extracts of page HTML
@@ -80,9 +81,21 @@ class ExtractFormatter extends HtmlFormatter {
 	 * @return array Array of removed DOMElements
 	 */
 	public function filterContent(): array {
+		$doc = $this->getDoc();
+
+		// Headings in a DIV wrapper may get removed by $wgExtractsRemoveClasses,
+		// move it outside the header to rescue it (T363445)
+		// https://www.mediawiki.org/wiki/Heading_HTML_changes
+		$headings = DOMCompat::querySelectorAll( $doc->documentElement, 'h1, h2, h3, h4, h5, h6' );
+		foreach ( $headings as $heading ) {
+			// @phan-suppress-next-line PhanTypeMismatchArgumentSuperType
+			if ( DOMCompat::getClassList( $heading->parentNode )->contains( 'mw-heading' ) ) {
+				$heading->parentNode->parentNode->insertBefore( $heading, $heading->parentNode );
+			}
+		}
+
 		$removed = parent::filterContent();
 
-		$doc = $this->getDoc();
 		$spans = $doc->getElementsByTagName( 'span' );
 
 		/** @var DOMElement $span */
diff --git a/tests/phpunit/ExtractFormatterTest.php b/tests/phpunit/ExtractFormatterTest.php
index ecc37a4..64c8ceb 100644
--- a/tests/phpunit/ExtractFormatterTest.php
+++ b/tests/phpunit/ExtractFormatterTest.php
@@ -67,6 +67,17 @@ class ExtractFormatterTest extends MediaWikiIntegrationTestCase {
 				'<span class="foo"><span style="bar: baz;" lang="qux">quux</span></span>',
 				false,
 			],
+			[
+				// New heading markup from T13555 (T363445)
+				"<p>hello</p><h2 id=\"heading\">heading</h2><p>bye</p>",
+				'<p>hello</p>' .
+					'<div class="mw-heading mw-heading2">' .
+					'<h2 id="heading">heading</h2>' .
+					'<span class="mw-editsection">xxx</span>' .
+					'</div>' .
+					'<p>bye</p>',
+				false,
+			],
 			[
 				// Verify that TOC is properly removed (HTML mode)
 				"Lead\n<h1>Section</h1>\n<p>Section text</p>",