[1.8.x] Fixed #26204 -- Reallowed dashes in top-level domains for URLValidator.

    # Host patterns

    hostname_re = r'[a-z' + ul + r'0-9](?:[a-z' + ul + r'0-9-]*[a-z' + ul + r'0-9])?'

    domain_re = r'(?:\.(?!-)[a-z' + ul + r'0-9-]+(?<!-))*'

    tld_re = r'\.(?:[a-z' + ul + r']{2,}|xn--[a-z0-9]+)\.?'

    tld_re = (

        '\.'                                # dot

        '(?!-)'                             # can't start with a dash

        '(?:[a-z' + ul + '-]{2,}'           # domain label

        '|xn--[a-z0-9]+)'                   # or punycode label

        '(?<!-)'                            # can't end with a dash

        '\.?'                               # may have a trailing dot

    )

    host_re = '(' + hostname_re + domain_re + tld_re + '|localhost)'

    regex = re.compile(

* Fixed :class:`~django.contrib.postgres.fields.RangeField` and

  :class:`~django.contrib.postgres.fields.ArrayField` serialization with

  ``None`` values (:ticket:`26215`).

* Reallowed dashes in top-level domain names of URLs checked by

  ``URLValidator`` to fix a regression in Django 1.8 (:ticket:`26204`).

http://invalid-.com

http://-invalid.com

http://invalid.com-

http://invalid.c-m

http://invalid.-com

http://inv-.alid-.com

http://inv-.-alid.com

file://localhost/path

:// should fail

http://foo.bar/foo(bar)baz quux

http://-error-.invalid/

http://dashinpunytld.trailingdot.xn--.

http://dashinpunytld.xn---

http://-a.b.co

http://a.b-.co

http://a.-b.co

http://255.255.255.255

http://224.0.0.0

http://224.1.1.1

http://dashintld.c-m

http://multipledashintld.a-b-c

http://evenmoredashintld.a---c

http://dashinpunytld.xn---c