unit_follow() causes on_ai_command_completed loop

[heyqule]

How to replicate

Select a group of unit and then right click on a friendly entity.

Issue

If I accidently click on a entity on the map mode. That triggers unit follow. Performance tanks once the group reach its destination. How heavy performance hit is relative to the group size, so large group takes heavier performance hit.

Point of interest in code

Factorio/mods/Unit_Control_0.3.11/script/unit_control.lua:1705
Factorio/mods/Unit_Control_0.3.11/script/unit_control.lua:1453