Possible bug in Media class.

[Roman Telezhynskyi]

Hello,

Today for my project I tried to find a solution for an issue with duplicate assets. Combining several approaches I managed to build an app to solve it. While debugging the app, I think, I found a bug in Media class.

File django/forms/widgets.py

@html_safe
class Media:
    def __init__(self, media=None, css=None, js=None):
        if media is not None:
            css = getattr(media, 'css', {})
            js = getattr(media, 'js', [])
        else:
            if css is None:
                css = {}
            if js is None:
                js = []
        self._css_lists = [css]
        self._js_lists = [js]

These two strings seems incorrect.
css = getattr(media, 'css', {})
js = getattr(media, 'js', [])

Instead of css and js attributes they return default values. I feel like it is just a developer error. If replace strings with

css = getattr(media, '_css', {})
js = getattr(media, '_js', [])

everything works again.

Can somebody confirm my guess?