KeyError if using 'password' as readonly_fields in UserAdmin

[Malte Gerth]

If 'password' is added as readonly_field in UserAdmin, a KeyError is thrown, as the UserChangeForm expects a password field to exists.

from django.contrib.auth.admin import UserAdmin as BaseUserAdmin

class UserAdmin(BaseUserAdmin):
    readonly_fields = ['username', 'password']

admin.site.register(User, UserAdmin)

class UserChangeForm(forms.ModelForm):
    # ...
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields['password'].help_text = self.fields['password'].help_text.format('../password/')
        # ...

[Malte Gerth]

This should fix the issue for now:

class UserChangeForm(forms.ModelForm):
    # ...
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if 'password' in self.fields.keys():
            self.fields['password'].help_text = self.fields['password'].help_text.format('../password/')
        # ...

[Tim Graham]

.keys() isn't needed, otherwise the fix looks reasonable. A test goes in tests/auth_tests/test_forms.py -- can you offer a pull request?

[Malte Gerth]

Ok, I tried to make a pull request
​https://github.com/django/django/pull/9833

[Tim Graham <timograham@…>]

In 874977d3:

Fixed #29270 -- Fixed UserChangeForm crash if password field is excluded.