diff -r 48c4eec2b7e6 -r 8c2e4d02f4ef wp/wp-includes/class-wp-comment.php
--- a/wp/wp-includes/class-wp-comment.php	Fri Sep 05 18:40:08 2025 +0200
+++ b/wp/wp-includes/class-wp-comment.php	Fri Sep 05 18:52:52 2025 +0200
@@ -33,7 +33,7 @@
 	 * @since 4.4.0
 	 * @var string
 	 */
-	public $comment_post_ID = 0;
+	public $comment_post_ID = '0';
 
 	/**
 	 * Comment author name.
@@ -99,7 +99,7 @@
 	 * @since 4.4.0
 	 * @var string
 	 */
-	public $comment_karma = 0;
+	public $comment_karma = '0';
 
 	/**
 	 * Comment approval status.
@@ -134,7 +134,7 @@
 	 * @since 4.4.0
 	 * @var string
 	 */
-	public $comment_parent = 0;
+	public $comment_parent = '0';
 
 	/**
 	 * Comment author ID.
@@ -144,7 +144,7 @@
 	 * @since 4.4.0
 	 * @var string
 	 */
-	public $user_id = 0;
+	public $user_id = '0';
 
 	/**
 	 * Comment children.
@@ -351,14 +351,16 @@
 	 *
 	 * @since 4.4.0
 	 *
-	 * @param string $name Property name.
-	 * @return bool
+	 * @param string $name Property to check if set.
+	 * @return bool Whether the property is set.
 	 */
 	public function __isset( $name ) {
 		if ( in_array( $name, $this->post_fields, true ) && 0 !== (int) $this->comment_post_ID ) {
 			$post = get_post( $this->comment_post_ID );
 			return property_exists( $post, $name );
 		}
+
+		return false;
 	}
 
 	/**