[0.45.4] Artillery attack on APC with 2 infantry units stops phase from ending

[Da-Nuker]

Megamek 0.45.4 as part of MekHQ
Win Java 1.8.0_211 64-bit

Launching an artillery weapon (tested Arrow IV artillery missile) onto an APC carrying two units of Battle Armor (tested Badger (C) Prime, and two Elemental Points) causes Megamek to freeze at end of firing phase.

The game does not freeze if it was there was only a single unit of BA carried.

This error message log was found in megameklog:
Exception in thread "Packet Pump" java.lang.ArrayIndexOutOfBoundsException: 6
at megamek.common.Entity.getInternalForReal(Entity.java:3146)
at megamek.common.Entity.getInternal(Entity.java:3139)
at megamek.common.Infantry.getInternal(Infantry.java:732)
at megamek.common.BattleArmor.getInternal(BattleArmor.java:783)
at megamek.common.BattleArmor.getTrooperAtLocation(BattleArmor.java:705)
at megamek.server.Server.damageExternalPassenger(Server.java:24894)
at megamek.server.Server.damageEntity(Server.java:23675)
at megamek.server.Server.damageEntity(Server.java:23018)
at megamek.server.Server.artilleryDamageHex(Server.java:36732)
at megamek.server.Server.artilleryDamageArea(Server.java:36843)
at megamek.server.Server.artilleryDamageArea(Server.java:36804)
at megamek.common.weapons.ArtilleryWeaponIndirectFireHandler.handle(ArtilleryWeaponIndirectFireHandler.java:452)
at megamek.server.Server.handleAttacks(Server.java:37078)
at megamek.server.Server.handleAttacks(Server.java:37007)
at megamek.server.Server.endCurrentPhase(Server.java:3136)
at megamek.server.Server.changeToNextTurn(Server.java:3473)
at megamek.server.Server.endCurrentTurn(Server.java:2463)
at megamek.server.Server.receiveAttack(Server.java:14058)
at megamek.server.Server.handle(Server.java:32801)
at megamek.server.Server$PacketPump.run(Server.java:369)

Files

Load the save game as player "Naga" and with target player "BA".
As Naga, Launch Arrow IV in direct fire mode at the surviving Badger (C) hex.

autosave.sav.gz

[mkerensky]

Looks like this doesn't actually have much if anything to do with artillery attacks. It's a case of random damage assignment to your battle armor passengers looking for nonexistant Trooper 6. I haven't tested it, but this will probably also happen if you have an IS squad and rear transport damage tries to find Trooper 5.

[mkerensky]

I added a couple of checks to make sure the array of existing battle armor troopers is large enough to have data for a 5th and 6th trooper before trying to damage them. Seems to have resolved the issue.