Fault with 'nochasecategory' sometimes incorrectly invalidating viable targets

[TheSilverHornet]

To prune a long story short, fight command uses Enemy_InLos_ValidTarget to see if a target is valid, which in turn uses
bool CMobileCAI::IsValidTarget

Which contains

if (owner->unitDef->noChaseCategory & enemy->category) return false

therefore in 'some cases' (I can't see why not all, however), fight commands will not realise an enemy that is in the 'nochasecategory' is something it should consider as a real target and stop moving when in range of.

Nochasecategory is intended to be what it says on the tin, eg a unit will still shoot and engage with units there, but not pursue if they run away. The code seems to not always amount to that end result.

spring/rts/Game/GameHelper.cpp

Line 491 in ab88be7

* the nearest enemy is an invalid target. (e.g. noChaseCategory)

spring/rts/Sim/Units/CommandAI/MobileCAI.cpp

Line 573 in ab88be7

bool CMobileCAI::IsValidTarget(const CUnit* enemy, CWeapon* weapon) const {

Discord discussions and more clips start around here: https://discord.com/channels/549281623154229250/724924957074915358/1233044341866369074

Example, this unit has 'nochasecategory="ALL"', will shoot a target as expected, but will not halt when fight-moved into range.
(However razorbacks with same tag, do halt correctly when given same command, so there is something else at play too)

When the nochasecategory tag is removed, they will halt at fight distance correctly.

nochaseonweaponon.mp4

nochaseoffweaponon.mp4

[TheSilverHornet]

Units.zip
corvoyr.zip
( Unit bos/cob and unitdef for the test unit above )

[sprunk]

Make a new tag because this behaviour (shoot a unit but don't stop for it) is useful.