Ticket #54375: 54375.3.diff

src/wp-includes/post.php

@@ -2157 +2157 @@
  * For all others, the 'publicly_queryable' value will be used.
  *
  * @since 5.7.0
+ * @since 5.9.0 Added `is_post_status_viewable` hook to filter the result.
  *
  * @param string|stdClass $post_status Post status name or object.
  * @return bool Whether the post status should be considered viewable.
@@ -2177 +2178 @@
                 return false;
         }
 
-        return $post_status->publicly_queryable || ( $post_status->_builtin && $post_status->public );
+        $is_viewable = $post_status->publicly_queryable || ( $post_status->_builtin && $post_status->public );
+
+        /**
+         * Filters whether a post status is considered "viewable".
+         *
+         * The returned filtered value must be a boolean type to ensure
+         * `is_post_status_viewable()` only returns a boolean. This strictness
+         * is by design to maintain backwards-compatibility and guard against
+         * potential type errors in PHP 8.1+. Non-boolean values (even falsey
+         * and truthy values) will result in the function returning false.
+         *
+         * @since 5.9.0
+         *
+         * @param bool     $is_viewable Whether the post status is "viewable" (strict type).
+         * @param stdClass $post_status Post status object.
+         */
+        return true === apply_filters( 'is_post_status_viewable', $is_viewable, $post_status );
 }
 
 /**