CalcSpatialInertia segfaults if passed a frame that isn't part of the plant

[nepfaff]

What happened?

The following segfaults:

from manipulation.station import LoadScenario
from pydrake.all import DiagramBuilder, RobotDiagram, RigidTransform, FixedOffsetFrame


from manipulation.station import LoadScenario, MakeHardwareStation


def main():
    builder = DiagramBuilder()

    scenario_str = """
    directives:
    - add_model:
        name: iiwa
        file: package://drake_models/iiwa_description/sdf/iiwa14_polytope_collision.sdf
    - add_weld:
        parent: world
        child: iiwa::iiwa_link_0
    """
    scenario = LoadScenario(data=scenario_str)
    station: RobotDiagram = builder.AddSystem(MakeHardwareStation(scenario))
    diagram = builder.Build()

    plant = station.plant()
    link7 = plant.GetBodyByName(f"iiwa_link_7")
    test_frame = FixedOffsetFrame(
        name="test_frame",
        P=link7.body_frame(),
        X_PF=RigidTransform(p=[0, 0, 0.1]),
    )
    plant.CalcSpatialInertia(
        context=plant.CreateDefaultContext(),
        frame_F=test_frame,
        body_indexes=[link7.index()],
    )


if __name__ == "__main__":
    main()

The reason seems to be that test_frame isn't part of the plant. No segfault if I add it to plant first.

Version

1.37.0

What operating system are you using?

Ubuntu 22.04

What installation option are you using?

pip install drake

Relevant log output

[ggould-tri]

Assigning component multibody plant; assigning @amcastro-tri for triage.

[jwnimmer-tri]

FYI I believe this is one concrete example of the larger issue #17734.