Copter: LOITER_TURNS command with zero radius uses radius of last time LOITER_TURNS command was executed

[rmackay9]

During the testing of this wiki pull request ArduPilot/ardupilot_wiki#3769 I found that if Copter executes a LOITER_TURNS command (in Auto mode) with the "Radius" field (aka "Param3") set to 0 it will use the radius from the last time.

Do people think this is the proper behaviour? Another option would be to default to the CIRCLE_RADIUS parameter value.

[muramura]

A radius of 0 meters should be treated as 0 meters.
This is valid for rotating on the fly.
At 0, I think it is not a good idea to use the radius value in Circle mode.

The functionality of this video can be achieved with a radius of 0 for LOITER_TURNS.
https://youtu.be/dEeq11sonIQ?t=98

[rmackay9]

@muramura, yes, you're right. If the user provides a radius of zero for the circle it should just rotate at the provided location.