Ticket #28672: 28672.2.diff

src/wp-admin/includes/template.php

@@ -1276 +1276 @@
  *     @type string $class     CSS Class to be added to the `<tr>` element when the
  *                             field is output.
  * }
+ * @return true|WP_Error    Will return WP_Error if the page and section have not been defined, true otherwise.
  */
 function add_settings_field($id, $title, $callback, $page, $section = 'default', $args = array()) {
-        global $wp_settings_fields;
+        global $wp_settings_fields, $wp_settings_sections;
 
         if ( 'misc' == $page ) {
                 _deprecated_argument( __FUNCTION__, '3.0', __( 'The miscellaneous options group has been removed. Use another settings group.' ) );
@@ -1290 +1291 @@
                 $page = 'reading';
         }
 
-        $wp_settings_fields[$page][$section][$id] = array('id' => $id, 'title' => $title, 'callback' => $callback, 'args' => $args);
+        $built_in_pages_and_sections = array(
+                'discussion' => array( 'default', 'avatars' ),
+                'general'    => array( 'default' ),
+                'media'      => array( 'default', 'embeds', 'uploads' ),
+                'permalink'  => array( 'optional' ),
+                'reading'    => array( 'default' ),
+                'writing'    => array( 'default', 'remote_publishing', 'post_via_email' ),
+        );
+
+        // check the built-in pages and sections
+        $section_check = ! empty( $built_in_pages_and_sections[ $page ] ) && in_array( $section, $built_in_pages_and_sections[ $page ] );
+
+        if ( ! $section_check ) {
+                // check any sections added by add_settings_section
+                $section_check = ! empty( $wp_settings_sections[ $page ][ $section ] );
+        }
+
+        $wp_settings_fields[ $page ][ $section ][ $id ] = array( 'id' => $id, 'title' => $title, 'callback' => $callback, 'args' => $args );
+
+        return ! $section_check ? new WP_Error( 'invalid_settings_section', sprintf( __('Settings page \'%s\', section \'%s\' does not exist.'), $page, $section ) ) : $section_check;
 }
 
 /**