Rviz crashes when using Marker with frame_locked = True

[xbaelus]

Hi,
Running on Ubuntu 18.04, ROS version dashing. When trying to use Marker with frame_locked = True, Rviz crashes with the following exception:

terminate called after throwing an instance of 'std::runtime_error'
  what():  can't compare times with different time sources

even though there's only one node and time is obtained in exactly the same way in all parts of my application. There's a simple script to reproduce the issue (rviz_crash.py.txt); the crash occurs as soon as mesh_test topic is added to visualization in Rviz. There's also a thread on answers.ros.org about this.

[jacobperron]

I think the bug is this line:

rviz/rviz_default_plugins/src/rviz_default_plugins/displays/marker/markers/marker_base.cpp

Line 108 in 045227a

stamp = rclcpp::Time();

We should ensure that the zero timestamp has the appropriate clock type so that the comparison doesn't fail. I'll open a PR with a fix shortly.