Fix bug when spawning a vehicle with rolename other than ego_vehicle (#…

…552)

Fixes a bug when spawning a vehicle with rolename other than ego_vehicle.

carla_spawn_objects/src/carla_spawn_objects/carla_spawn_objects.py

@@ -46,8 +46,8 @@ class CarlaSpawnObjects(CompatibleNode):
     def __init__(self):
         super(CarlaSpawnObjects, self).__init__('carla_spawn_objects')
 
-        self.objects_definition_file = self.get_param('objects_definition_file')
-        self.spawn_sensors_only = self.get_param('spawn_sensors_only', None)
+        self.objects_definition_file = self.get_param('objects_definition_file', '')
+        self.spawn_sensors_only = self.get_param('spawn_sensors_only', False)
 
         self.players = []
         self.vehicles_sensors = []

ros_compatibility/src/ros_compatibility/node.py

@@ -25,7 +25,7 @@ class CompatibleNode(object):
         def __init__(self, name, **kwargs):
            pass
 
-        def get_param(self, name, alternative_value=None, alternative_name=None):
+        def get_param(self, name, alternative_value=None):
             if name.startswith('/'):
                 raise RuntimeError("Only private parameters are supported.")
             return rospy.get_param("~" + name, alternative_value)
@@ -142,12 +142,10 @@ def __init__(self, name, **kwargs):
                 parameter_overrides=[param],
                 **kwargs)
 
-        def get_param(self, name, alternative_value=None, alternative_name=None):
-            if alternative_name is None:
-                alternative_name = name
+        def get_param(self, name, alternative_value=None):
             return self.get_parameter_or(
                 name,
-                Parameter(alternative_name, value=alternative_value)).value
+                Parameter(name, value=alternative_value)).value
 
         def get_time(self):
             t = self.get_clock().now()