WizardView.get_form destroys 'instance' and 'queryset' from get_form_kwargs

[Gary Reynolds]

In the case where the wizard author might like to populate the form with an existing model instance or formset from a queryset based through get_form_kwargs it get's destroyed by a call to kwargs.update({'instance': self.get_form_instance(step)}) or kwargs.update({'queryset': self.get_form_instance(step)}).

While I can appreciate that there is already a way to populate this value by overloading the get_form_instance method, I don't think that we should be destructive of another way to achieve it. Additionally I find it less confusing if I can define all kwargs to be passed to my form/formset init method in one place (ie. in get_form_kwargs) rather than splitting this logic into two places.

I've attached a patch against r17511 which includes a test case.

[steph]

Updated patch (some test changes)

[Jannis Leidel]

In [17651]:

Fixed #17677 -- Made sure the WizardView doesn't accidentally overwrite the instance or queryset form parameters when they are already set by the get_form_kwargs method. Thanks to goodtune and Stephan Jäkel.