Infinite Recursion possible in 2.4

We have a condition_dict containing the following function:

def need_further_steps(wizard):
    data = wizard.get_cleaned_data_for_step("0") or {}
    if data.get("no_invoices_needed", False):
        return False
    return True

The call to WizardView.get_cleaned_data_for_step then calls WizardView.get_form, which used to reference self.form_list, but the following commit changes this to self.get_form_list(), which then calls the user-supplied condition_dict functions, which then calls our need_further_steps function above, which calls WizardView.get_cleaned_data_for_step, and so on ad infinitum. https://github.com/jazzband/django-formtools/commit/533a83053deab2adeb72de079e813aae78b03c1a

Perhaps our custom condition function is bad, but it doesn’t seem too unreasonable?

[jsma]

Please revert 533a83053, which introduced a major bug and was not a proper solution for the new feature request (to dynamically add forms that aren’t in the initial form_list). For those that require this new feature, please provide a working example of your use cases and how you were doing this prior to 2.4. A proper API needs to be created and tested for this new feature request, without breaking existing documented functionality. That has not been done yet. A proper API shouldn’t require any hacks around infinite recursion errors, it should be designed so these errors are impossible.

[schinckel]

The latter - to come up with a proper solution.