Overriding Choices for a field in the Form not working when using ModelForm | Django 3.2

[Swaroop P]

Hi All

Facing the following issue after migrating to 3.2.

Example:

class SomeModel(models.Model):
       field1 = models.CharField(choices=[])

class SomeModelForm(forms.ModelForm):

     __init__(*args, **kwargs):
         super().__init__(*args **kwargs)
         self.fields['field1'].choices = <some choices dynamically generated>

    class Meta:
         model = SomeModel
         fields = [ 'field1' ]

In the above case any choice selected is shown with the error "not a valid choice" this is happening because model fields is revalidated again in modelform._post_clean() function.

Intermediate solution is to remove choices from modelfield and reinitalize field in form init wiht dynamic choices. But In previous versions We had choices to only override some attributes of a field rather than reinitalizing whole field.

Thanks