Moveit: Rviz crashes frequently if Show Trail and Loop Animation are used together

[felixvd]

Description

When displaying a plan with the MotionPlanning plugin, Rviz tends to crash if both Loop Animation and Show Trail (in the Planned Path category) are turned on while the animation is playing.

Your environment

• ROS Distro: Melodic
• OS Version: Ubuntu 18.04
• Source build

Steps to reproduce

Plan a path (optionally: execute it), turn on "Loop Animation" and then turn on "Show Trail". If that doesn't work, turn them both on/off a few times. I could reproduce it fairly reliably this way.

Expected behaviour

Rviz shouldn't crash.

Actual behaviour

Rviz crashes

Backtrace or Console output

[rviz_acd9b44678e6_219_7606801427590083783-7] process has died [pid 289, exit code -11, cmd /opt/ros/melodic/lib/rviz/rviz -d /opt/ros/melodic/share/panda_moveit_config/launch/moveit_empty.rviz __name:=rviz_acd9b44678e6_219_7606801427590083783 __log:=/root/.ros/log/2c6030e6-606f-11ea-b8eb-0242ac110002/rviz_acd9b44678e6_219_7606801427590083783-7.log].
log file: /root/.ros/log/2c6030e6-606f-11ea-b8eb-0242ac110002/rviz_acd9b44678e6_219_7606801427590083783-7*.log

[Dale-Koenig]

Played around this for an hour or so. It seems this (and some related things) are solved by removing the call to QApplication::processEvents(); from RobotStateVisualization::load

As it is, there can be bad unintented recursion where TrajectoryVisualization::update calls TrajectoryVisualization::changedShowTrail calls RobotStateVisualization::load calls QApplication::processEvents which again leads to a call to TrajectoryVisualization::update at which point very bad things happen.

[rhaschke]

Fixed via #1941.

[felixvd]

Thanks, this went at record speed :)