#4360 Unit destroyed by engine explostion blast has kill awarded to the wrong Unit

[luiges90]

1. A unit is destroyed and its engine explodes, destroying the other unit's CT.
2. At the same time, two of our units fire at the cored unit
3. And that kill goes to one of the unit fired at it? It doesn't even hit the enemies' CT!

Weapons fire for Molrosa MLR-1S (Apanc)
    Medium Laser at Stinger STG-3R (Lyran Commonwealth); needs 7, rolls 8 : hits  (using Rear table) LA
        Stinger STG-3R (Lyran Commonwealth) takes 6 damage to LA.
        6 damage transfers to LTR.
        Stinger STG-3R (Lyran Commonwealth) takes 6 damage to LTR.
            Armor destroyed, 1 Internal Structure remaining
            Critical hit on LT. Roll is 10; 2 locations.
            CRITICAL HIT on Heat Sink.
            CRITICAL HIT on Jump Jet.

    Medium Laser at Stinger STG-3R (Lyran Commonwealth); needs 7, rolls 11 :  - Direct Blow - hits  (using Rear table) LTR
        Stinger STG-3R (Lyran Commonwealth) takes 7 damage to LTR.
             SECTION DESTROYED,
        6 damage transfers to CTR.
            Critical hit on LT. Roll is (2+1) = 3; no effect.
        Stinger STG-3R (Lyran Commonwealth) takes 6 damage to CTR.
            Armor destroyed, 4 Internal Structure remaining
            Critical hit on CT. Roll is (7+1) = 8; 1 location.
            CRITICAL HIT on Engine.

    Medium Laser at Stinger STG-3R (Lyran Commonwealth); needs 7, rolls 12 :  - Direct Blow - hits  (using Rear table) CTR
        Stinger STG-3R (Lyran Commonwealth) takes 7 damage to CTR.
             SECTION DESTROYED,
        Stinger STG-3R (Lyran Commonwealth) has taken 6 engine hits this phase.
        Checking for engine explosion on 10, roll is 11.
        ***The safety systems on the engine fail catastrophically resulting in a cascading engine failure!
*** Stinger STG-3R (Lyran Commonwealth) DESTROYED by engine explosion! ***

        Start Secondary Damage Report.
        >Stinger STG-3R (Lyran Commonwealth) suffers catastrophic damage, but the autoeject system was engaged.

Stinger STG-3R (Lyran Commonwealth) must make a piloting skill check (High-G).
    Needs 6 [5 (ejecting) + 1 (automatic ejection) - 2 (landing in clear terrain) + 2 (High-G)], rolls 7 : succeeds.
*** MechWarrior Jeremy Rein (Lyran Commonwealth) DESTROYED by deadly ejection! ***
        Molrosa MLR-1S (Apanc) is hit for 12 damage!
        Molrosa MLR-1S (Apanc) takes 5 damage to CT.
            5 Armor remaining.
        Molrosa MLR-1S (Apanc) takes 5 damage to LT.
            10 Armor remaining.
        Molrosa MLR-1S (Apanc) takes 2 damage to CT.
            3 Armor remaining.

        Phoenix Hawk PXH-1K (Apanc) is hit for 3 damage!
        Phoenix Hawk PXH-1K (Apanc) takes 3 damage to LA.
            9 Armor remaining.

        Hermes II HER-4K "Hermes III" (Apanc) is hit for 6 damage!
        Hermes II HER-4K "Hermes III" (Apanc) takes 5 damage to LT.
            9 Armor remaining.
        Hermes II HER-4K "Hermes III" (Apanc) takes 1 damage to CT.
            16 Armor remaining.

        Wolverine WVR-6R (Apanc) is hit for 12 damage!
        Wolverine WVR-6R (Apanc) takes 5 damage to RA.
            7 Armor remaining.
        Wolverine WVR-6R (Apanc) takes 5 damage to LL.
            9 Armor remaining.
        Wolverine WVR-6R (Apanc) takes 2 damage to CT.
             11 Internal Structure remaining
            Critical hit on CT. Roll is 9; 1 location.
            CRITICAL HIT on Jump Jet.

        UrbanMech UM-R60 (Lyran Commonwealth) is hit for 12 damage!
        UrbanMech UM-R60 (Lyran Commonwealth) takes 5 damage to LT.
             SECTION DESTROYED,
        3 damage transfers to CT.
            Critical hit on LT. Roll is 5; no effect.
        UrbanMech UM-R60 (Lyran Commonwealth) takes 3 damage to CT.
             SECTION DESTROYED,
        UrbanMech UM-R60 (Lyran Commonwealth) has taken 6 engine hits this phase.
        Checking for engine explosion on 10, roll is 8.
        Engine safety systems remain in place.
*** UrbanMech UM-R60 (Lyran Commonwealth) DESTROYED by damage! ***
            Critical hit on CT. Roll is 9; 1 location.
            CRITICAL HIT on Engine.
        UrbanMech UM-R60 (Lyran Commonwealth) takes 5 damage to LA.
        5 damage transfers to LT.
        UrbanMech UM-R60 (Lyran Commonwealth) takes 5 damage to LT.
        5 damage transfers to CT.
        UrbanMech UM-R60 (Lyran Commonwealth) takes 5 damage to CT.
        UrbanMech UM-R60 (Lyran Commonwealth) takes 2 damage to RT.
            6 Armor remaining.

        Wasp WSP-1A (Lyran Commonwealth) is hit for 3 damage!
        Wasp WSP-1A (Lyran Commonwealth) takes 3 damage to CT.
            3 Armor remaining.

        Wasp WSP-1A #2 (Lyran Commonwealth) is hit for 3 damage!
        Wasp WSP-1A #2 (Lyran Commonwealth) takes 3 damage to RT.
             SECTION DESTROYED,
LIMB BLOWN OFF Right Arm blown off.
        2 damage transfers to CT.
            Critical hit on RT. Roll is 5; no effect.
        Wasp WSP-1A #2 (Lyran Commonwealth) takes 2 damage to CT.
            4 Armor remaining.

        Hunchback HBK-4N (Lyran Commonwealth (Reinforcements)) is hit for 12 damage!
        Hunchback HBK-4N (Lyran Commonwealth (Reinforcements)) takes 5 damage to LA.
            11 Armor remaining.
        Hunchback HBK-4N (Lyran Commonwealth (Reinforcements)) takes 5 damage to RA.
            11 Armor remaining.
        Hunchback HBK-4N (Lyran Commonwealth (Reinforcements)) takes 2 damage to LL.
            18 Armor remaining.

        MechWarrior Jose Wichman (Lyran Commonwealth) is hit for 3 damage!
        Infantry is hit by area-effect artillery!!! Damage doubled.
        Infantry platoon caught in the open!!!  Damage doubled.
        MechWarrior Jose Wichman (Lyran Commonwealth) takes 12 damage to MEN.
             PLATOON KILLED,
*** MechWarrior Jose Wichman (Lyran Commonwealth) DESTROYED by damage! ***

        End Secondary Damage Report.
            Critical hit on CT. Roll is (6+1) = 7; no effect.

    Medium Laser at Stinger STG-3R (Lyran Commonwealth); needs 7, rolls 5 : misses

...

Weapons fire for Hermes II HER-4K "Hermes III" (Apanc)
    Large Laser at UrbanMech UM-R60 (Lyran Commonwealth); needs 6, rolls 11 :  - Direct Blow - hits  RT
        UrbanMech UM-R60 (Lyran Commonwealth) takes 10 damage to RT.
            Armor destroyed, 3 Internal Structure remaining
            Critical hit on RT. Roll is (7+1) = 8; 1 location.
            CRITICAL HIT on Heat Sink.

    Large Laser at UrbanMech UM-R60 (Lyran Commonwealth); needs 6, rolls 5 : misses

...

Winner is: TEAM #1

Apanc: 4836 BV remaining (from 5885 initially) 0 BV fled
Lyran Commonwealth: 426 BV remaining (from 3338 initially) 0 BV fled
Lyran Commonwealth (Reinforcements): 5651 BV remaining (from 5741 initially) 0 BV fled

...

UrbanMech UM-R60 (Lyran Commonwealth)
Pilot : Eric Winter [4/5] ( 6 hit(s)  )
Kills : 0
Destroyed by Hermes II HER-4K "Hermes III" (Apanc) <<< ??

[Nicholas Walczak]

Well, I'm pretty sure I know what's going on here, but I haven't come up with the best way to fix it yet.

It coems down to Server.creditKill(target, attacker), which when called will credit the attacker with the kill for the target, if the target is doomed or its crew is doomed, and kill credit hasn't already been claimed.

The problem is, this only gets called through WeaponHandlers or Server.resolvePhysicalAttack. So, the engine explosion doesn't claim a kill at any point. If nothing else fired at the unit, in the victory phase it would say "Destroyed by pilot error" because the Entity.killer variable would be set to ENTITY_NONE.

There are a few questions in my mind...

First, who should get credit for the kill in this case? To be clear, my understanding is that Unit A shoots at Unit B, which has its reactor go critical. The resulting engine explosion in Unit B kills Unit C. Who claims kill credit for Unit C? I feel like there could be arguments made for three possibilities: A because he caused the engine explosion, B because it was his engine that exploded, and "pilot error" because C was dumb enough to stand close enough to get killed by an engine explosion.

[Dylan Myers]

I think the generally accepted answer to your last question is that Unit A would in cases where the explosion was caused that way and Unit A is an enemy of Unit C. Unit B would in cases where Unit A is an ally of Unit C and Unit B is an enemy of Unit C, or in cases where Unit B explodes from overheating causing ammo to boom off. Unit C (pilot error) should only come from exploding his own ammo from overheating. I'm pretty sure that covers all scenarios. Though maybe Pilot Error if Unit B and C are allies and Unit B explodes from overheat.