add sanity check for command-int conversion

[peterbarker]

Replaces #28790

This provides a useful return value to the GCS that they've passed in invalid lat/lng in their command-long positions. Which they shouldn't be using anyway.

Board,plane
CubeOrange,0
Pixhawk1-1M,40

[IamPete1]

We are supposed to deal with NaNs, it might be fine if the command is not using those params. We could convert from NaN which is no value for float Int32 max which is no value for int32 according to the spec.

[peterbarker]

Oof. Hmmm. Will think about this more in the morning.

Problem is that if we just squash them to zero them we may end up triggering the sanitise-using-a-default-location code....

[IamPete1]

The spec calls for INT32 max for invalid. (https://mavlink.io/en/messages/common.html#COMMAND_INT), so NaN should be converted to that. Then your new range check will bounce if it is a location.

[peterbarker]

OK, squashed to INT32_MAX as you suggest - seems the best way forward here.

Note that this will be a behavioural change - previously we would have treated these as 0.

[tridge]

need to see if the change of behaviour is safe

[tridge]

we need to see if there may be any commands that relied on the previous zero, and now will get INT32_MAX, motor test is a possible issue

[IamPete1]

Code changes look good now. We do generally need to be better handling incoming commands with invalid values.