generic incorrectly narrowed based on first parameter in the else branch of an if expression

[DetachHead]

from typing import TypeVar

T1 = TypeVar("T1")
T2 = TypeVar("T2")


def foo(a: T1, b: T2) -> T1 | T2:
    return a

invalid = 1 if 1 else foo(1, "s") # error: Argument 2 to "foo" has incompatible type "str"; expected "int"
valid = foo(1, "s") if 1 else 1

https://mypy-play.net/?mypy=latest&python=3.10&gist=791645f9a348afc114cf3769ed85c30a

[sobolevn]

This happens because

self.infer_function_type_arguments_using_context(
                callee, context)

infers def [T1, T2] (a: T1'3, b: T2'4) -> Union[T1'3, T2'4] to be def (a: builtins.int*, b: builtins.int*) -> builtins.int* using Literal[1] (from invalid = 1 if ...) as context. I will look into it, but it might be quite complex.