TYPO3 Core

Creating a mailform works fine, we have the liberty to use any kind of characters in field label. Unfortunately, if a single quote is used in the label, when submitting the form, a javascript report this error (using Firebug with Firefox):

missing ) after argument list

Here's why:

<form onsubmit="return validateForm('mailform','name,Nom d'utilisateur,email,Email:','','Erreur - ces champs sont obligatoires :','Adresse de courriel non valide')" ...

As you can see, the label is passed as an argument to validateForm function. The single quote used in label "Nom d'utilisateur" breaks the string prematurely.

Result:
the form is sent directly by e-mail and is never validated, this also means we can submit empty forms.

It has been tested and repeated with these Typo3 versions:

4.3.3
4.3.4
4.4.0

(issue imported from #M15307)