Enter activity does not account for moving Targets.

[pchote]

From #13699:

The Enter code does not account for the target moving after the movement (e.g. Drag) has started. If the target is moving then the unit will move to the original target position, notice that it is no longer there, and then fail/cancel itself.

What we really want here to fix this properly is to fix the IMove.MoveIntoTarget implementations to deal with moving targets. This means that Drag etc can adjust themselves to move always towards the actual position of the target. For this to work well we would need to introduce a WDist targetMoveLimit to the method call that can abort the activity if the target is moving too far/fast from the original location. This then covers the Hijacker issue plus any visual glitches that could be caused by the target moving too fast.

[ghost]

The hijacker part should be fixed by #15661 (comment).

[pchote]

This will come for free with my fix for #16139. Adding to the milestone so that we don't forget to test and close this.