| ⇢ | A | YiisoftConfig added | |
| ⇢ | A | YiiConfig added |
| ⇢ | B | YiiConfig::__construct() added | |
| ⇢ | A | YiiConfig::mergeRules() added | |
| ⇢ | A | YiisoftConfig::__construct() added | |
| A | ↘ | B | ErrorHandler::handleFallbackExceptionMessage() got worse |
| B | ↗ | A | Application::run() improved |
| B | ↘ | C | Request::getPreferredLanguage() got worse |