List comprehension with TypedDict fails type checking

Bug Report

(A clear and concise description of what the bug is.)

To Reproduce

I've made a file t.py:

from typing import TypedDict, List


class Dct(TypedDict):
    x: int


def foo() -> List[Dct]:
    return [item for item in [{"x": 3}]]

Expected Behavior

(Write what you thought would happen.)

Without the list comprehension, it works fine:

from typing import TypedDict, List


class Dct(TypedDict):
    x: int


def foo() -> List[Dct]:
    return [{"x": 3}]

Actual Behavior

$ mypy t.py
t.py:9: error: List comprehension has incompatible type List[Dict[str, int]]; expected List[Dct]  [misc]
Found 1 error in 1 file (checked 1 source file)

Your Environment

• Mypy version used: mypy 0.812
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: 3.8.8
• Operating system and version:

Inizia riproducendo il report con l'esempio t.py fornito e mypy 0.812, confrontando il risultato della list comprehension con la restituzione diretta della lista. Traccia il percorso del controllo dei tipi per le list comprehension e i valori TypedDict; il lavoro è completo quando la comprehension viene accettata come List[Dct] senza introdurre regressioni nei controlli correlati.