URLField validation fails with "://" on the path and no scheme

[Samus_]

according to RFC3986[1] urls containing colons on the path are valid but the current validation fails when the scheme is missing and there's an empty path:

Python 2.6.4rc2 (r264rc2:75497, Oct 20 2009, 02:55:11)
[GCC 4.4.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import django
>>> django.VERSION
(1, 3, 0, 'alpha', 0)
>>> from django.forms import URLField
>>> f = URLField()
>>> f.clean('www.example.com/://')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/samus/django-trunk/django/forms/fields.py", line 164, in clean
    self.run_validators(value)
  File "/home/samus/django-trunk/django/forms/fields.py", line 153, in run_validators
    raise ValidationError(errors)
django.core.exceptions.ValidationError: [u'Enter a valid URL.']

discussion: ​http://groups.google.com/group/django-developers/browse_thread/thread/7b6780645ac882a7

[1] ​http://www.rfc-ref.org/RFC-TEXTS/3986/chapter3.html#sub3

[Adam Nelson]

I think ​urlsplit should be used instead of a custom regex. If scheme is None, then use 'http' as the default and rebuild the url out of the component parts. Don't use scheme='http' as that has a weird issue with urls like '/hello/world' not getting the default scheme.

[Chris Beaven]

(In [14657]) Fixes #13804 -- URLField validation failure for a url containing ':' on the path and no scheme

[Chris Beaven]

(In [14658]) Fixes #13804 -- URLField validation failure for a url containing ':' on the path and no scheme. Backport of r14657