Problem url: http://prestashop_b.test2.b2bit.cz/
Nette: 2.3.0
PHP: 5.5.12
Javascript netteForms.js: http://nette.github.io/resources/js/netteForms.min.js
or the one included in vendor.

When creating application form and adding rule for text input Form::URL, the problem url noted above does not pass on submitting whereas Validators::isUrl returns true for such url.

Other urls, without "_" pass in both cases just fine.

Excluding netteForms.js lets the problem url pass too, but it has a side effect - no global client-side validation.

Thanks