验收四路模型并优化拓扑求解性能

tests/test_mechanical_solver_causalization.py

@@ -488,6 +488,36 @@ class MechanicalSolverCausalizationTests(unittest.TestCase):
         for value in result.series["mass.a"]:
             self.assertAlmostEqual(value, 0.0, places=12)
 
+    def test_ideal_stop_ignores_zero_velocity_roundoff_inside_boundary_band(self) -> None:
+        system, _mass = _single_mass_system(
+            0.0,
+            stoptype=1.0,
+            x0=0.0,
+            xmin=0.0,
+            xmax=1.0,
+        )
+        reducer = system.mechanical_state_reducer
+        previous_state = [0.0, 2.0e-32]
+        current_state = [0.0, -1.0e-32]
+
+        def dense_state(time: float) -> list[float]:
+            fraction = float(time)
+            return [
+                0.0,
+                previous_state[1]
+                + fraction * (current_state[1] - previous_state[1]),
+            ]
+
+        transition = reducer.state_transition(
+            0.0,
+            previous_state,
+            1.0,
+            current_state,
+            dense_state,
+        )
+
+        self.assertIsNone(transition)
+
     def test_ideal_upper_stop_projects_a_high_speed_impact(self) -> None:
         system, _mass = _single_mass_system(
             100.0,