Nested ArrayField with nullable base field generates invalid SQL

[Josef Kolář]

When I have model

class NestedNullableIntegerArrayModel(PostgreSQLModel):
    field = ArrayField(ArrayField(models.IntegerField(null=True)))

and trying to save data

NestedNullableIntegerArrayModel(field=[[None, None], [None, None]]).save()

and Django generates

INSERT INTO "postgres_tests_nestednullableintegerarraymodel" ("field") VALUES (%s) RETURNING "postgres_tests_nestednullableintegerarraymodel"."id"

with expectable params

([[None, None], [None, None]], )

and this query fails in postgres on

ERROR:  column "field" is of type integer[] but expression is of type text[]
LINE 1: ...estednullableintegerarraymodel" ("field") VALUES (ARRAY['{NU...
                                                             ^
HINT:  You will need to rewrite or cast the expression.

But, if I use one of values is not None, model is saved successfully:

NestedNullableIntegerArrayModel(field=[[None, None], [None, 42]]).save()