Version 2.0.24 bill to email validation bug seems present in version 3.0.18

[Ghostgames]

We are running VirtueMart 3.0.18. No 3rd part plugsin except for a USPS and Fedex shipping modules. We are experiencing a bug where an anonymous shopper (one who is not logged into the site as a registered user) can click on the "Add/Edit billing address information" button on the Cart page and enter an invalid email (for example, just "johndoe" vs "johndoe@domain.com").

A search of the forums found this bug was present in Virtuemart 2.0.24 in the post at http://forum.virtuemart.net/index.php?topic=119490.msg406565#msg406565
This topic lists a user applied fix for version 2.0.24.

I thought this bug should be reported against version 3.0.18 and I wanted to ask if the fix listed for 2.0.24 is still applicable for 3.0.18 before we try to apply it?

[GJC Web Design]

the code required will certainly be similar ( std. JS check of email) but may be simpler to do just on a loose focus of the email field or similar so the enforcement is immediate

[Ghostgames]

I lack in-depth javascript and Joomla expertise, so I was hoping the VM 2.0.24 explicit instructions would apply to VM 3.0.18. Unfortunately, the code in /components/com_virtuemart/views/user/tmpl/edit_address.php in VM 3.0.18 has changed from 2.0.24 so the specific instruction no longer apply. If someone can point me to where the myValidator(f, t) function is now located in the VirtueMart code base, I could try the suggested patch, but I have no idea where it might be.