fix: Response::download() causes TypeError

TypeError
CodeIgniter\CodeIgniter::displayPerformanceMetrics(): Argument #1 ($output) must be of type string, null given, called in .../CodeIgniter4/system/CodeIgniter.php on line 500

system/CodeIgniter.php

@@ -489,20 +489,26 @@ protected function handleRequest(?RouteCollectionInterface $routes, Cache $cache
  $this->response = $response;
  }
 
- // Cache it without the performance metrics replaced
- // so that we can have live speed updates along the way.
- // Must be run after filters to preserve the Response headers.
- if (static::$cacheTTL > 0) {
- $this->cachePage($cacheConfig);
- }
+ // Skip unnecessary processing for special Responses.
+ if (! $response instanceof DownloadResponse && ! $response instanceof RedirectResponse) {
+ // Cache it without the performance metrics replaced
+ // so that we can have live speed updates along the way.
+ // Must be run after filters to preserve the Response headers.
+ if (static::$cacheTTL > 0) {
+ $this->cachePage($cacheConfig);
+ }
 
- // Update the performance metrics
- $output = $this->displayPerformanceMetrics($this->response->getBody());
- $this->response->setBody($output);
+ // Update the performance metrics
+ $body = $this->response->getBody();
+ if ($body !== null) {
+ $output = $this->displayPerformanceMetrics($body);
+ $this->response->setBody($output);
+ }
 
- // Save our current URI as the previous URI in the session
- // for safer, more accurate use with `previous_url()` helper function.
- $this->storePreviousURL(current_url(true));
+ // Save our current URI as the previous URI in the session
+ // for safer, more accurate use with `previous_url()` helper function.
+ $this->storePreviousURL(current_url(true));
+ }
 
  unset($uri);