Fixed IsTimedTrajectory on empty trajectories.

Author: Michael Koval

src/prpy/util.py

@@ -762,7 +762,8 @@ def IsTimedTrajectory(trajectory):
     @returns: True if the trajectory is timed, False otherwise
     """
     cspec = trajectory.GetConfigurationSpecification()
-    return cspec.ExtractDeltaTime(trajectory.GetWaypoint(0)) is not None
+    empty_waypoint = numpy.zeros(cspec.GetDOF())
+    return cspec.ExtractDeltaTime(empty_waypoint) is not None
 
 def ComputeEnabledAABB(kinbody):
     """

tests/test_util.py

@@ -0,0 +1,28 @@
+import openravepy
+import prpy.util
+import unittest
+
+class IsTimedTrajectoryTests(unittest.TestCase):
+    def setUp(self):
+        self.env = openravepy.Environment()
+        self.traj = openravepy.RaveCreateTrajectory(self.env, '')
+
+    def test_IsTimed_ReturnsTrue(self):
+        cspec = openravepy.ConfigurationSpecification()
+        cspec.AddDeltaTimeGroup()
+
+        self.traj.Init(cspec)
+        self.assertTrue(prpy.util.IsTimedTrajectory(self.traj))
+
+        self.traj.Insert(0, [0.])
+        self.assertTrue(prpy.util.IsTimedTrajectory(self.traj))
+
+    def test_IsNotTimed_ReturnsFalse(self):
+        cspec = openravepy.ConfigurationSpecification()
+        cspec.AddGroup('joint_values test_robot 0', 1, 'linear')
+
+        self.traj.Init(cspec)
+        self.assertFalse(prpy.util.IsTimedTrajectory(self.traj))
+
+        self.traj.Insert(0, [0.])
+        self.assertFalse(prpy.util.IsTimedTrajectory(self.traj))