Regression for truthy bool with getattr

[ilinum]

The following code generates an error on latest master but no on latest release (with --enable-error-codes=truthy-bool):

def f(obj: object) -> None:
    print("{}".format(
        getattr(type(obj), "__foo__", "") or "unknown"  # E: "builtins.getattr" returns "object" which does not implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
    ))

f("")

It's clearly a false positive, if your run the code you see that it prints unknown.

[ilinum]

Using @hauntsaninja's mypy_primer, it pointed to #14178.

$ cat test.py
# flags: --enable-error-code truthy-bool
def f(obj: object) -> None:
    print("{}".format(
        getattr(type(obj), "__foo__", "") or "unknown"  # E: "builtins.getattr" returns "object" which does not implement __bool__ or __len__ so it could always be true in boolean context  [truthy-bool]
    ))
$ python3 mypy_primer.py -p test.py --bisect --debug --old v0.991
...
4471c7e76f27ee51eb8d47a4803097ec15c62128 is the first bad commit
...

This is likely the same underlying issue as #14481.

@ilevkivskyi

[JukkaL]

Here's a bit simpler example that reproduces the issue:

def f(t: type[object]) -> None:
    o: object = getattr(t, "x", "") or ""

This looks different from #14481, as there are no TypedDicts involved here.