Wrong inference with default argument values

[jkmnt]

Got the unexpected result: default value of function argument is treated as the 'only' value.

Minimal example:

from astroid import extract_node

bad, good = extract_node("""
def bad(foo: str | None = None):
    a = 1 if foo else ""  #@

def good(foo: str):
    a = 1 if foo else ""  #@
""")

print(bad.value.inferred())
print(good.value.inferred())

Result:

[<Const.str l.3 at 0x27945e7eae0>]
[<Const.int l.6 at 0x27945e7ec90>, <Const.str l.6 at 0x27945e7ecc0>]

I expected the first .inferred to return two results. The second one is ok.

Astroid version: 4.0.2

[jkmnt]

Nailed it down to this line. test.iter is called just once. If we call it second time, it would correctly yield Uninferable signalling
the true foo value is unknown.

astroid/astroid/nodes/node_classes.py

Line 3137 in 2966719

test = next(self.test.infer(context=context.clone()))