validate_email accepts trailing dash

[jason@…]

In django 1.6 an EmailField (validate_email) will accept an address with a trailing dash at the end. Example: 'foo@…-'
In django 1.4 it would trigger a ValidationError, so I believe this is a regression.

Tested like so:

>>> from django.core.validators import validate_email
>>> validate_email('foo@bar.com-')

expected: throws ValidationError
actual: no error thrown

This may be related to #12027, about the same behavior, but with a trailing dot. As with that bug, a trailing dash causes sendmail to throw an error.

[Tomek Paczkowski]

Tests are good, patch applies.

[Erik Romijn <eromijn@…>]

In 424fe76349a2e34eafef13c2450a7a1f4d3115a6:

Fixed #22579 -- Corrected validation for email to reject trailing slash

Thanks to Claude Paroz for the report and patch and Tomasz
Paczkowski for the review.

[Erik Romijn <eromijn@…>]

In 2a66d12e77821fbd4f2e4c3cb93eb9f84ca6f9ab:

[1.7.x] Fixed #22579 -- Corrected validation for email to reject trailing slash

Backport of 424fe76349a2e34eafef13c2450a7a1f4d3115a6 from master.

[Erik Romijn <eromijn@…>]

In 50a289d05fba760716287d582c7ea19edd1159cc:

[1.6.x] Fixed #22579 -- Corrected validation for email to reject trailing slash

Backport of 424fe76349a2e34eafef13c2450a7a1f4d3115a6 from master.