Issue #2175765 by alexpott, Gábor Hojtsy: Fix comment in...

Issue #2175765 by alexpott, Gábor Hojtsy: Fix comment in system_theme_default() to not refer to obsolete function

core/modules/system/system.admin.inc

@@ -33,7 +33,7 @@ function system_theme_default() {
       // Rebuild the menu. This duplicates the menu_router_rebuild() in
       // theme_enable(). However, modules must know the current default theme in
       // order to use this information in hook_menu() or hook_menu_alter()
-      // implementations, and doing the variable_set() before the theme_enable()
+      // implementations, and saving the configuration before the theme_enable()
       // could result in a race condition where the theme is default but not
       // enabled.
       \Drupal::service('router.builder')->rebuild();