WordPress
diff --git a/‎src/wp-includes/html-api/class-wp-html-tag-processor.php‎
Lines changed: 9 additions & 0 deletions b/‎src/wp-includes/html-api/class-wp-html-tag-processor.php‎
Lines changed: 9 additions & 0 deletions
diff --git a/‎tests/phpunit/tests/html-api/wpHtmlTagProcessorModifiableText.php‎
Lines changed: 2 additions & 1 deletion b/‎tests/phpunit/tests/html-api/wpHtmlTagProcessorModifiableText.php‎
Lines changed: 2 additions & 1 deletion
@@ -4161,6 +4161,15 @@ static function ( $tag_match ) {
 
 			case 'TEXTAREA':
 			case 'TITLE':
+				$plaintext_content = strtr(
+					$plaintext_content,
+					array(
+						'<' => '&lt;',
+						'&' => '&amp;',
+						'>' => '&gt;',
+					)
+				);
+
 				$plaintext_content = preg_replace_callback(
 					"~</(?P<TAG_NAME>{$this->get_tag()})~i",
 					static function ( $tag_match ) {
 
@@ -414,9 +414,10 @@ public function test_updates_basic_modifiable_text_on_supported_nodes( string $h
 			'Should have modified the text at the target node.'
 		);
 
-		$this->assertSame(
+		$this->assertEqualHTML(
 			$transformed,
 			$processor->get_updated_html(),
+			'<body>',
 			"Should have transformed the HTML as expected when modifying the target node's modifiable text."
 		);
 	}