Crash after dynamically adding plugin AckermannSteering

[gzfuzz]

Environment

• OS Version: Ubuntu 22.04
• Source or binary build?
  source build
  gz-sim version: 907efc3
  built with
  gcc version: 11.4.0 (Ubuntu 11.4.0-1ubuntu1~22.04)
  build options: -DCMAKE_BUILD_TYPE=Coverage

Description

• Expected behavior: Gazebo doesn't crash
• Actual behavior: Gazebo crashes

Steps to reproduce

1. gz sim a.txt -r
2. add plugin AckermannSteering with gz service command

gz service --timeout 10000 -s /world/world_0/entity/system/add --reptype gz.msgs.Boolean --reqtype gz.msgs.EntityPlugin_V --req 'entity {
  id: 4
}
plugins {
  name: "gz::sim::systems::AckermannSteering"
  filename: "gz-sim-ackermann-steering-system"
  innerxml: "<left_joint>front_left_wheel_joint</left_joint>\n        \n<left_joint>rear_left_wheel_joint</left_joint>\n        \n<right_joint>front_right_wheel_joint</right_joint>\n        \n<right_joint>rear_right_wheel_joint</right_joint>\n        \n<left_steering_joint>front_left_wheel_steering_joint</left_steering_joint>\n        \n<right_steering_joint>front_right_wheel_steering_joint</right_steering_joint>\n        \n<kingpin_width>1.0</kingpin_width>\n        \n<steering_limit>0.5</steering_limit>\n        \n<wheel_base>1.0</wheel_base>\n        \n<wheel_separation>1.25</wheel_separation>\n        \n<wheel_radius>0.3</wheel_radius>\n        \n<min_velocity>-1</min_velocity>\n        \n<max_velocity>1</max_velocity>\n        \n<min_acceleration>-3</min_acceleration>\n        \n<max_acceleration>3</max_acceleration>\n      "
}'

could also be reproduced by extracting a.tar.gz, and then run

bash a.sh

Output

Stack trace (most recent call last) in thread 57857:
#11   Object "[0xffffffffffffffff]", at 0xffffffffffffffff, in 
#10   Object "/lib/x86_64-linux-gnu/libc.so.6", at 0x7f0f952a684f, in 
#9    Object "/lib/x86_64-linux-gnu/libc.so.6", at 0x7f0f95214ac2, in 
#8    Object "/lib/x86_64-linux-gnu/libstdc++.so.6", at 0x7f0f90f51252, in 
#7    Object "/home/ren/play/robot/workspace/install/lib/libgz-sim8.so.8", at 0x7f0f8ebf0c8f, in 
#6    Object "/home/ren/play/robot/workspace/install/lib/libgz-sim8.so.8", at 0x7f0f8ebf0ccf, in 
#5    Object "/home/ren/play/robot/workspace/install/lib/libgz-sim8.so.8", at 0x7f0f8ebf0d43, in 
#4    Object "/home/ren/play/robot/workspace/install/lib/libgz-sim8.so.8", at 0x7f0f8ebf0e15, in 
#3    Object "/home/ren/play/robot/workspace/install/lib/libgz-sim8.so.8", at 0x7f0f8ebf0ead, in 
#2    Object "/home/ren/play/robot/workspace/install/lib/libgz-sim8.so.8", at 0x7f0f8ebe0fb1, in 
#1    Object "/data/play/robot/workspace/install/lib/gz-sim-8/plugins/libgz-sim-ackermann-steering-system.so", at 0x7f0f50591097, in gz::sim::v8::systems::AckermannSteering::PostUpdate(gz::sim::v8::UpdateInfo const&, gz::sim::v8::EntityComponentManager const&)
#0    Object "/data/play/robot/workspace/install/lib/gz-sim-8/plugins/libgz-sim-ackermann-steering-system.so", at 0x7f0f50593472, in gz::sim::v8::systems::AckermannSteeringPrivate::UpdateVelocity(gz::sim::v8::UpdateInfo const&, gz::sim::v8::EntityComponentManager const&)
Segmentation fault (Address not mapped to object [(nil)])

[iche033]

sim crashes because the specified joints are not available in the box model. #2521 prevents the crash.