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Trailing dot in email (Was: Re: Possible bug according to Rasmus Leerdorf)

From: Lars Gunther <gunther@keryx.se>
Date: Sun, 04 Apr 2010 22:24:25 +0200
Message-ID: <4BB8F579.6080506@keryx.se>
To: public-html@w3.org
2010-04-04 18:07, Lars Gunther skrev:
>
> http://www.w3.org/Bugs/Public/show_bug.cgi?id=9404

My bug was marked a duplicate to this one:

http://www.w3.org/Bugs/Public/show_bug.cgi?id=9392

Which in turn was marked invalid. It seems this behaviour is intentional:

http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2009-August/022486.html

I will probably raise this to an issue, since the "hard data" in this 
case is ambiguous and thus hardly something we can use to break an RFC.

The ambiguity is the fact that one program did in fact refuse to send 
the email (GNU mail). The user in question said it "worked" but that is 
hardly "hard data". Did it work all the time? How many failed attempts 
have ther been that he has never noticed?

The fact that some MTAs will allow mail to be transmitted even if their 
format is flawed is not a strong enough argument. It is rather something 
that one should file a bug for at the bug system for those MTAs.

Ninjas of various kinds will always experiment with the system and find 
loopholes. It is not the mission of HTML5 to make such loopholes a 
standard behaviour.

Rasmus Leerdorf has just submitted fixes to FILTER_VALIDATE_EMAIL for 
PHP. This will make the use of trailing dots invalid according to the 
recommended test for the most widely deployed server-side scripting 
language.

It will probably mean that Mediawiki some time in the future are going 
to disallow it, as well as Facebook, since using the built in 
functionality sooner or later will trickle into their code base.

Perl's CPAN email validator uses an regexp inspired by Jeffrey Friedl:

http://cpansearch.perl.org/src/RJBS/Email-Valid-0.183_001/lib/Email/Valid.pm


 From a developer perspective, it makes best sense having the client 
side validation be as close to the server side validation as possible in 
its functionality. Of course they can not be identical always, but the 
less the divergence is, the easier it is to develop apps.


P.S. I am sorry I missed this discussion in August. I can't be everywhere...

-- 
Lars Gunther
http://keryx.se/
http://twitter.com/itpastorn/
http://itpastorn.blogspot.com/
Received on Sunday, 4 April 2010 20:24:57 GMT

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