[still bugged]Rain of Gore

[Nexhro]

Describe the Bug:
A player controlling Venser's Journal can gain life from it when his/her opponent controls Rain of Gore.edit
Further testing proved that only Rain of Gore 's controller is affected by its effect in general.

Which card did behave improperly ?
- Rain of Gore

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
CIA v2, Duel

What exactly should be the correct behavior/interaction ?
If a spell or ability would cause its controller to gain life, that player loses that much life instead.

Are any other cards possibly affected by this bug ?
Possibly other permanents with an activated or triggered ability causing lifegain (tested with Ajani's Mantra => same bug).
Possibly instants or sorceries that cause Rain of Gore 's controller's opponent to gain life.

Edit: Clarified issue. Not sure why card highlightning doesn't work anymore after I've editted, but here's the card for reference.

[Korath]

We can't do Rain of Gore properly without a great deal of effort, since the gain_life() function doesn't get told whose effect is causing gain of life. Same as Psychic Purge and Guerrilla Tactics and Spiritual Focus, which can't tell whose effect caused you to discard; but for Rain of Gore, the approximation is much more approximate, enough so that it's basically a different card than what was printed.

[Aswan jaguar]

Fixed by drool66 in commit 218c226.

[Korath]

Still doesn't check the controller. Trivially provable by casting it, then casting a Stream of Life on the AI.

[Aswan jaguar]

In the case you are saying, it shouldn't trigger as the controller of Stream of Life isn't AI, right?
I didn't test that, concentrating on the original bug which is "fixed" as back then Rain of Gore affected only Rain of Gore's controller.

[drool66]

Korath, it's working fine for me. Did you rebuild Magic.exe for EA_LICH?

[Korath]

It can't possibly be working; gain_life() doesn't have access to the controller of the spell or ability. Look, try it with one of the cards templated "Each player gains [some amount of] life." Most aren't in Manalink, but Putrid Warrior or Triskaidekaphobia are reasonably easy to test if you pick the gain life mode. Only the player who controls the trigger should lose life.

[drool66]

I see. So it currently works as "If a spell or ability would cause a player to gain life, that player loses that much life instead."
Maybe not that hard to do as a find and replace, kind of how I did counters to get Nest of Scarabs working. Then we can just pass the controller of the effect as trigger_cause, since it's currently unused in TRIGGER_GAIN_LIFE.encode it in trigger_cause of XTRIGGER_REPLACE_GAIN_LIFE.

[Korath]

I'd be wary of passing anything other than a card in trigger_cause (unless trigger_cause_controller is -1); like affected_card_controller/affected_card, there's places scattered about that treat the pair as identifying a card instance if it looks like one. Change of control notably doesn't, though it really should.

Genuinely separate bug with this card, newly-introduced: lifelinked damage caused by a spell or ability is no longer affected, and should be. It's just combat damage with lifelink that Rain of Gore doesn't replace. And I suppose noncombat damage with lifelink if it's somehow caused by something that's not a spell or ability, though I can't think of how that could happen offhand.

This is the actual hard part of Rain of Gore, and the reason why I haven't implemented it in Shandalar: it's easy, though extremely tedious, to add a controller-of-spell-or-ability parameter to gain_life(), but you'd have to do the same for all sources of noncombat damage too, and propagate that all the way down until it gets to the gain_life call. The controller of the damage isn't enough; consider cards like Tracker or ones that cause creatures to fight. All this for the off chance that the damage source has lifelink and this one card that's been out of standard for fifteen years and was never popular in any other format happens to be on the bf. It's like Artificial Evolution: too much effort for too little return, and even there New Blood would be able to use the same framework.

Oh, and Sanctimony and Whimsy still use the exe version of gain_life().

[drool66]

I see. I'll change the instructions to only call gain_life_from_lifelink if:
instance->token_status & (STATUS_COMBAT_DAMAGE|STATUS_FIRST_STRIKE_DAMAGE)
I'll also move the flag from trigger_cause to a new global(ugh...), and stop there for now. Of course, that means the name isn't entirely accurate any more.