[whatwg] Make "foo at bar.com, " a valid email address list

[Mounir Lamouri]

Hi,

For the moment, a valid email address list is a set of comma-separated
tokens where each tokens are a valid email address so in the case of
"foo at bar.com, ", "foo at bar.com" is a valid email address but not "".

Unfortunately, as soon as you want to put a UI on top of that, values
will always be appended by ", ". Indeed, a comma have to be added to
mark that the user is now editing another email address so the UI can
suggests new ones. Without adding the comma automatically, the user
would have to add it by hand to have the UI suggesting new entries.
So, if we do not fix the specifications, all <input type='email'
multiple> with a UI will be whether invalid or really annoying to implement.

You can found an example of that kind of UI in GMail.

I think we should change the specifications so an email address list
will be valid if it's ending with a comma (plus trailing whitespaces).
In other words, if a list of email address have more than one token, the
last one can be the empty string.

We are thinking of implementing this change in Gecko 2.0 so feedback are
very welcome.

Thanks,
--
Mounir