Wrong types when pattern matching `int` with `http.HTTPStatus`

[injust]

Bug Report

When using structural pattern matching to compare an int vs an http.HTTPStatus instance (and vice versa), mypy gets the type wrong or thinks the code is unreachable.

To Reproduce

https://mypy-play.net/?mypy=latest&python=3.13&flags=strict%2Cwarn-unreachable&gist=843b35aa16cac4c7357b94902cc9057b

from http import HTTPStatus
from typing import reveal_type

code = 200

match code:
    case HTTPStatus():
        pass
    case HTTPStatus.OK:
        reveal_type(code)
    case _:
        pass


status = HTTPStatus.OK

match status:
    case 200:
        reveal_type(status)
    case _:
        pass

Expected Behavior

The revealed types should be int and Literal[HTTPStatus.OK].

Actual Behavior

main.py:10: note: Revealed type is "Literal[http.HTTPStatus.OK]"
main.py:19: note: Revealed type is "Never"
Success: no issues found in 1 source file

Your Environment

• Mypy version used: 1.15.0
• Mypy command-line flags: --strict --warn-unreachable
• Python version used: 3.13

[brianschubert]

Related pyright issue: microsoft/pyright#10235

[A5rocks]

This is kind of #17317 but with match statements I think?

[sterliakov]

@A5rocks why? #17317 is about accessing enum fields on instances,

from enum import Enum, auto

class Glass(Enum):
    HALF_FULL = auto()
    HALF_EMPTY = auto()

    def print(self) -> None:
        reveal_type(self.HALF_FULL)  # N: Revealed type is "enum.auto"
        reveal_type(Glass.HALF_FULL)  # N: Revealed type is "Literal[__main__.Glass.HALF_FULL]?"
        
        if self == self.HALF_FULL: pass  # E: Non-overlapping equality check (left operand type: "Glass", right operand type: "auto")  [comparison-overlap]
        if self == Glass.HALF_FULL: pass

do these accesses have some intimate relationship with enums matching?

Ah, I get it now. #16327 was closed as dupe of #17317 and is really related to this one - I have strong feeling that #16327 is a completely different issue, accessing members on the class and on the instance is not handled equivalently now.