AttributeError in assert_and_parse_html on Python 3.5+

[Dmitry Dygalo]

I got this on Django 1.9 with Python 3.5:

    def assert_and_parse_html(self, html, user_msg, msg):
        try:
            dom = parse_html(html)
        except HTMLParseError as e:
>           standardMsg = '%s\n%s' % (msg, e.msg)
E           AttributeError: 'HTMLParseError' object has no attribute 'msg'

As I see it happens when input HTML is not valid (I tried with "< div></ div>")

PR: ​https://github.com/django/django/pull/6943

[Tim Graham <timograham@…>]

In d7a09726:

Fixed #26922 -- Fixed SimpleTestCase.assertHTMLEqual() crash on Python 3.5+.

[Tim Graham <timograham@…>]

In b3f96b5f:

[1.10.x] Fixed #26922 -- Fixed SimpleTestCase.assertHTMLEqual() crash on Python 3.5+.

Backport of d7a097265b1842843a73ce0da36ef98bacac8a3e from master