CharField(blank=True) treated as nullable

[zach-waggoner]

What's wrong

When I run mypy with this plugin enabled, it infers the type for CharFields with blank=True as Optional[str].

How is that should be

I believe this is incorrect, as blank=True only permits empty strings, not NULL. It seems like this was allegedly fixed in #39, but I'm still having the same issue. I noticed that if I remove the following lines from DjangoContext.get_field_nullability, it works:

if not nullable and isinstance(field, CharField) and field.blank:
    return True

System information

• OS:
• python version: 3.9.7
• django version: 3.2.9
• mypy version: 0.910
• django-stubs version: 1.9.0
• django-stubs-ext version: N/A

[sobolevn]

@zach-waggoner PR is welcome!

[flaeppe]

I cannot reproduce this, feel free to reopen with a breaking case.