CharField.widget_attrs should respect its super

[Ruy Asan]

The contract of the Field.widget_attrs method is that it returns a dictionary (even says so in the docstring), however CharField.widget_attrs may return None (when the if clause fails). It should at least return an empty dict, or better yet, simply modify whatever the super-method returns.

​Pull Request Here
​Patch Here

[Mathieu Agopian]

Hello rubyruy,

Thanks for the feedback, and indeed, i believe django.forms.fields.CharField.widget_attrs should return a dictionary in all cases, as written in django.forms.fields.Field.widget_attrs, but even more, it should return an updated dict from it.

I'm thus marking this ticket as accepted, but i also added the "needs tests" and "patch needs improvement" flags.
Regarding the improvements, you use attrs.setdefault, while it should rather be using attrs.update: child's attributes should have precedence.

As a side note, the github django repository is only a mirror, the official repository is on SVN (on this very track). Thus the pull request won't be accepted on github. Also, please attach the patch (with tests if possible, that would be brilliant) to this ticket, as it'll ease the review and everybody's work!

[mmcnickle]

The attached patch makes sure widget_attrs() always returns a dictionary, even if it's empty.

I didn't think that the super call was necessary as Field only returns an empty dictionary by default. If this ever changes, then we can add the super call then.

[mmcnickle]

Make sure CharField? always returns a dictionary from widget_attrs()

[Preston Timmons]

Slightly modified patch

[Preston Timmons]

Same patch using super method

[Preston Timmons]

The patch and test look good. I added a slightly modified patch to fix a typo, added a reference to this ticket, and remove a redundant test in15912.2.diff.

Also attached a version using a super call for the committers disgression.

[Julien Phalip]

In [17096]:

Fixed #15912 -- Ensured that forms.CharField.widget_attrs() always returns a dictionary. Thanks to tsabi and rubyruy for the report and to mmcnickle and prestontimmons for the patch.