Merge pull request #148 from personalrobotics/bugfix/traj_length_check

Changed GetDuration=0.0 error to warning.

Author: mkoval

src/prpy/base/robot.py

@@ -457,9 +457,18 @@ def ExecuteTrajectory(self, traj, defer=False, timeout=None, period=0.01, **kwar
             else:
                 return traj
 
-        # Verify that the trajectory is timed.
+        # Verify that the trajectory is timed by checking whether the first
+        # waypoint has a valid deltatime value.
+        cspec = traj.GetConfigurationSpecification()
+        if cspec.ExtractDeltaTime(traj.GetWaypoint(0)) is None:
+            raise ValueError('Trajectory cannot be executed, it is not timed.')
+
+        # Verify that the trajectory has non-zero duration.
         if traj.GetDuration() <= 0.0:
-            raise ValueError('Attempted to execute untimed trajectory.')
+            import warnings
+            warnings.warn('Executing zero-length trajectory. Please update the'
+                          ' function that produced this trajectory to return a'
+                          ' single-waypoint trajectory.', FutureWarning)
 
         # TODO: Check if this trajectory contains the base.
         needs_base = util.HasAffineDOFs(traj.GetConfigurationSpecification())