Copter: 4.1 Internal Error 1048576 in Guided mode if velocity control used after attitude control

[rmackay9]

Internal Error 1048576 can be triggered in Guided mode if the velocity controller is used after the attitude controller. This can be reproduced in SITL by doing the following:

• start SITL
• GUIDED
• arm throttle
• attitude 1 0 0 0 0.6 (enter this many times to takeoff using the attitude controller)
• attitude 1 0 0 0 0.4 (enter this many times to land using the attitude controller)
• velocity 0 0 -1 (to attempt to takeoff using the velocity controller)

The panic shown below appears in SITL. The issue is likely that the position controller is not being re-initialised before Guided mode's velocity controller tries to use it.

[rmackay9]

This has been fixed by #17539 and should be included in beta6