Ticket #31675: 31675.4.diff

src/wp-includes/widgets.php

@@ -803 +803 @@
 
         $i = count($wp_registered_sidebars) + 1;
 
-        if ( empty( $args['id'] ) ) {
-                /* translators: %s: the id argument */
-                _doing_it_wrong( __FUNCTION__, sprintf( __( 'You should set %s in the arguments array.' ), '<code>id</code>' ), '4.2.0' );
-        }
+        $id_is_empty = empty( $args['id'] );
 
         $defaults = array(
                 'name' => sprintf(__('Sidebar %d'), $i ),
@@ -821 +818 @@
 
         $sidebar = wp_parse_args( $args, $defaults );
 
+        if ( $id_is_empty ) {
+                /* translators: %1$s: the id argument */
+                _doing_it_wrong( __FUNCTION__, sprintf( __( 'No %1$s was set in the arguments array for the "%2$s" sidebar. Defaulting to "%3$s". Manually set the %1$s to  "%3$s" to silence this notice and keep existing sidebar area content.' ), '<code>id</code>', $sidebar['name'], $sidebar['id'] ), '4.2.0' );
+        }
+
         $wp_registered_sidebars[$sidebar['id']] = $sidebar;
 
         add_theme_support('widgets');