`Optional[Dict[str, Any]]` broken when trying to get the schema

[dbarrosop]

This broke since 0.17:

import json
from typing import Any, Dict, Optional

from pydantic import BaseModel


class Test(BaseModel):
    something: Optional[Dict[str, Any]]


print(json.dumps(Test.schema(), indent=4))

Traceback:

$ python test.py
Traceback (most recent call last):
  File "test.py", line 11, in <module>
    print(json.dumps(Test.schema(), indent=4))
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/main.py", line 292, in schema
    s = model_schema(cls, by_alias=by_alias)
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 191, in model_schema
    model, by_alias=by_alias, model_name_map=model_name_map, ref_prefix=ref_prefix
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 461, in model_process_schema
    model, by_alias=by_alias, model_name_map=model_name_map, ref_prefix=ref_prefix
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 482, in model_type_schema
    f, by_alias=by_alias, model_name_map=model_name_map, ref_prefix=ref_prefix
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 238, in field_schema
    ref_prefix=ref_prefix,
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 440, in field_type_schema
    ref_prefix=ref_prefix,
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 608, in field_singleton_schema
    ref_prefix=ref_prefix,
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 515, in field_singleton_sub_fields_schema
    sub_fields = [sf for sf in sub_fields if sf.include_in_schema()]
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/schema.py", line 515, in <listcomp>
    sub_fields = [sf for sf in sub_fields if sf.include_in_schema()]
  File "/home/dbarroso/.virtualenvs/nornir/lib/python3.6/site-packages/pydantic/fields.py", line 359, in include_in_schema
    return len(self.validators) > 1 or self.validators[0][1] != is_none_validator

Is this a regression or has something changed that I need to address?

Thanks!

[samuelcolvin]

Thanks for reporting @dbarrosop, hopefully fixed on #362