From e4ff46e6e0300d7626cdf21f17db6609a6c59692 Mon Sep 17 00:00:00 2001
From: Wickedness <y2keui@nate.com>
Date: Sun, 5 Jul 2026 14:17:23 +0900
Subject: [PATCH] Reject stale battle save effects

---
 scripts/verify-battle-save-normalization.mjs |  2 ++
 src/game/state/battleSaveState.ts            | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/scripts/verify-battle-save-normalization.mjs b/scripts/verify-battle-save-normalization.mjs
index 12b4535..66283f6 100644
--- a/scripts/verify-battle-save-normalization.mjs
+++ b/scripts/verify-battle-save-normalization.mjs
@@ -105,6 +105,7 @@ try {
     ['too high buff bonus', { battleBuffs: [{ ...validState.battleBuffs[0], criticalBonus: 100 }] }],
     ['unknown buff unit id', { battleBuffs: [{ ...validState.battleBuffs[0], unitId: 'ghost-unit' }] }],
     ['duplicate buff unit id', { battleBuffs: [validState.battleBuffs[0], { ...validState.battleBuffs[0] }] }],
+    ['defeated buff target', { units: patchUnit(0, { hp: 0 }), attackIntents: [], battleBuffs: [{ ...validState.battleBuffs[0], unitId: 'liu-bei' }] }],
     ['invalid status kind', { battleStatuses: [{ ...validState.battleStatuses[0], kind: 'poison' }] }],
     ['too many status turns', { battleStatuses: [{ ...validState.battleStatuses[0], turns: 10 }] }],
     ['too long status label', { battleStatuses: [{ ...validState.battleStatuses[0], label: 'x'.repeat(33) }] }],
@@ -112,6 +113,7 @@ try {
     ['too high status power', { battleStatuses: [{ ...validState.battleStatuses[0], power: 100 }] }],
     ['unknown status unit id', { battleStatuses: [{ ...validState.battleStatuses[0], unitId: 'ghost-unit' }] }],
     ['duplicate status unit kind', { battleStatuses: [validState.battleStatuses[0], { ...validState.battleStatuses[0] }] }],
+    ['defeated status target', { units: patchUnit(2, { hp: 0 }), attackIntents: [], battleStatuses: [{ ...validState.battleStatuses[0], unitId: 'rebel-1' }] }],
     ['invalid stats shape', { battleStats: { 'liu-bei': { damageDealt: 10 } } }],
     ['invalid stats value', { battleStats: { 'liu-bei': { ...validState.battleStats['liu-bei'], actions: 1.5 } } }],
     ['too high stats value', { battleStats: { 'liu-bei': { ...validState.battleStats['liu-bei'], damageDealt: 1000000 } } }],
diff --git a/src/game/state/battleSaveState.ts b/src/game/state/battleSaveState.ts
index a8063c3..41e5e74 100644
--- a/src/game/state/battleSaveState.ts
+++ b/src/game/state/battleSaveState.ts
@@ -163,6 +163,10 @@ export function isValidBattleSaveState(state: unknown, options: BattleSaveValida
     return false;
   }
 
+  if (!areEffectsTargetingLiveUnits(state.battleBuffs, state.battleStatuses, units)) {
+    return false;
+  }
+
   if (
     !isOptionalItemStockRecord(state.itemStocks, options) ||
     !isOptionalBuffArray(state.battleBuffs, options) ||
@@ -282,6 +286,21 @@ function areAttackIntentsTargetingLiveUnits(attackIntents: BattleSaveAttackInten
   return attackIntents.every((intent) => liveUnitIds.has(intent.attackerId) && liveUnitIds.has(intent.targetId));
 }
 
+function areEffectsTargetingLiveUnits(
+  battleBuffs: unknown,
+  battleStatuses: unknown,
+  units: SavedBattleUnitState[]
+) {
+  const liveUnitIds = new Set(units.filter((unit) => unit.hp > 0).map((unit) => unit.id));
+  const buffTargetsAreLive =
+    battleBuffs === undefined ||
+    (Array.isArray(battleBuffs) && battleBuffs.every((buff) => isRecord(buff) && liveUnitIds.has(String(buff.unitId))));
+  const statusTargetsAreLive =
+    battleStatuses === undefined ||
+    (Array.isArray(battleStatuses) && battleStatuses.every((status) => isRecord(status) && liveUnitIds.has(String(status.unitId))));
+  return buffTargetsAreLive && statusTargetsAreLive;
+}
+
 function isSavedBattleUnitState(value: unknown, options: BattleSaveValidationOptions): value is SavedBattleUnitState {
   if (!isRecord(value) || typeof value.id !== 'string' || value.id.length === 0 || !isEquipmentSet(value.equipment, options)) {
     return false;