Lithoform Engine error copying clue card draw ability

[JohnPetfield]

In beta, pay 2 to sacrifice a clue, hold priority try to copy the ability with Lithoform Engine, results in an error and rollback

Game exception occurred: java.lang.NullPointerException Server version: 1.4.52-V1-beta3 (build: 2022-09-17 05:55) mage.view.StackAbilityView.updateTargets(StackAbilityView.java:157) mage.view.StackAbilityView.(StackAbilityView.java:79) mage.view.GameView.(GameView.java:94) mage.server.game.GameSessionPlayer.prepareGameView(GameSessionPlayer.java:211) mage.server.game.GameSessionPlayer.getGameView(GameSessionPlayer.java:198) mage.server.game.GameSessionPlayer.lambda$playMana$6(GameSessionPlayer.java:97) java.util.Optional.ifPresent(Optional.java:159) mage.server.game.GameSessionPlayer.playMana(GameSessionPlayer.java:96) mage.server.game.GameController.lambda$playMana$21(GameController.java:862) mage.server.game.GameController.perform(GameController.java:988) mage.server.game.GameController.perform(GameController.java:981) mage.server.game.GameController.playMana(GameController.java:862) mage.server.game.GameController.lambda$init$3aa0d15c$2(GameController.java:198) mage.game.events.EventDispatcher.fireEvent(EventDispatcher.java:28) mage.game.events.PlayerQueryEventSource.playMana(PlayerQueryEventSource.java:80) mage.game.GameImpl.firePlayManaEvent(GameImpl.java:2696) mage.player.human.HumanPlayer.playManaHandling(HumanPlayer.java:1389) mage.player.human.HumanPlayer.playMana(HumanPlayer.java:1371) mage.abilities.costs.mana.ManaCostsImpl.pay(ManaCostsImpl.java:138) mage.abilities.AbilityImpl.activate(AbilityImpl.java:404) mage.abilities.ActivatedAbilityImpl.activate(ActivatedAbilityImpl.java:253) mage.players.PlayerImpl.playAbility(PlayerImpl.java:1371) mage.players.PlayerImpl.activateAbility(PlayerImpl.java:1497) mage.player.human.HumanPlayer.activateAbility(HumanPlayer.java:2127) mage.player.human.HumanPlayer.activateAbility(HumanPlayer.java:2150) mage.player.human.HumanPlayer.priority(HumanPlayer.java:1228) mage.game.GameImpl.playPriority(GameImpl.java:1539) mage.game.turn.Step.priority(Step.java:61) mage.game.turn.Phase.playStep(Phase.java:184) mage.game.turn.Phase.play(Phase.java:89) mage.game.turn.Turn.play(Turn.java:132) mage.game.GameImpl.playTurn(GameImpl.java:1055) mage.game.GameImpl.play(GameImpl.java:965) mage.game.GameImpl.start(GameImpl.java:941) mage.server.game.GameWorker.call(GameWorker.java:34) java.util.concurrent.FutureTask.run(FutureTask.java:266) java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) java.lang.Thread.run(Thread.java:748)

[awjackson]

This doesn't happen in 1.4.50V2, so it's a regression.

[jeffwadsworth]

[[Lithoform Engine]]

[github-actions[bot]]

Lithoform Engine - (Gatherer) (Scryfall) (EDHREC)

{4} Legendary Artifact {2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy. {3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy. {4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

[Alex-Vasile]

Line 157 is: https://github.com/magefree/mage/blob/9084180937f7f7a7ad8f42d615b59633202a426b/Mage.Common/src/main/java/mage/view/StackAbilityView.java#L157

I have a feeling it's game.getCard which is returning null since the clue is gone, so .getIdName() will cause the NPE.

[awjackson]

Why are CardView and StackAbilityView using different logic here? I can see displaying a different message depending on whether the target StackObject is a spell or an ability, but this displays different messages depending on whether the thing doing the targetting is a spell or an ability.

In my tree I changed the StackAbilityView code to match the CardView code and now it doesn't crash and it looks like this when you mouse over the ability on the stack:

Does this look like what you intended? @jeffwadsworth It matches the log message, which also includes the text of the targeted ability rather than the name of its source object.

[jeffwadsworth]

That looks great to me. I can't find the original user request for targets to show up on the stackobjects, but I think it was a useful request.

[Alex-Vasile]

Does the current testing suite support catching a bug like this?