Fix error rendering with unclosed Output buffers (joomla#41188)

Author: Fedik

libraries/src/Exception/ExceptionHandler.php

@@ -94,6 +94,11 @@ public static function render(\Throwable $error)
  $app->redirect('index.php');
  }
 
+ // Clear all opened Output buffers to prevent misrendering
+ for ($i = 0, $l = ob_get_level(); $i < $l; $i++) {
+ ob_end_clean();
+ }
+
  /*
  * Try and determine the format to render the error page in
  *