Cannot send meta=None in from_json to flask-wtf>=0.14

[virlos]

The classmethod from_json has default meta=None, which fails at https://github.com/lepture/flask-wtf/blob/master/flask_wtf/form.py#L85 as that assumes meta is a dict if present:

File "/usr/local/lib/python2.7/dist-packages/wtforms_json/init.py", line 233, in from_json
**kwargs
File "/usr/local/lib/python2.7/dist-packages/wtforms/form.py", line 212, in call
return type.call(cls, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/flask_wtf/form.py", line 85, in init
kwargs.setdefault('meta', {}).setdefault('csrf', csrf_enabled)
AttributeError: 'NoneType' object has no attribute 'setdefault'

[alanhamlett]

Looks like a bug in Flask-WTF:

https://github.com/lepture/flask-wtf/issues/new

[virlos]

Arguably, the definition in WTForms also has meta=None, but it's doc at http://wtforms.readthedocs.io/en/latest/forms.html#wtforms.form.Form.__init__ says: meta – If provided, this is a dictionary of values to override attributes on this form’s meta instance.

[alanhamlett]

You're right, just created #48 to fix this.

[virlos]

@alanhamlett, it shows as a 'referenced' item here. pallets-eco/flask-wtf#278