laravel/framework — pull request #5456 by leesherwood (2014-08-14 15:45:38+00:00)
Title: Make isValid() check only for UploadedFile instances

This should fix: https://github.com/laravel/framework/issues/5455

Simply moved the `isValid` out so it only runs for uploaded files as the method only exists on the UploadedFile class, not the underlying File class.