From 8d37225259759ad67efa9a45b300d7d57a0dc430 Mon Sep 17 00:00:00 2001
From: NightKev <34855794+DayKev@users.noreply.github.com>
Date: Fri, 8 Nov 2024 13:45:14 -0800
Subject: [PATCH] Transform and Imposter will now fail when either Pokemon is
 fused

---
 src/data/ability.ts | 27 ++++++++++++++++++++++-----
 src/data/move.ts    |  8 +++++---
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/data/ability.ts b/src/data/ability.ts
index 08dc1ed27a4..736f5862530 100644
--- a/src/data/ability.ts
+++ b/src/data/ability.ts
@@ -2463,12 +2463,15 @@ export class PostSummonCopyAllyStatsAbAttr extends PostSummonAbAttr {
   }
 }
 
+/**
+ * Used by Imposter
+ */
 export class PostSummonTransformAbAttr extends PostSummonAbAttr {
   constructor() {
     super(true);
   }
 
-  async applyPostSummon(pokemon: Pokemon, passive: boolean, simulated: boolean, args: any[]): Promise<boolean> {
+  async applyPostSummon(pokemon: Pokemon, _passive: boolean, simulated: boolean, _args: any[]): Promise<boolean> {
     const targets = pokemon.getOpponents();
     if (simulated || !targets.length) {
       return simulated;
@@ -2477,17 +2480,31 @@ export class PostSummonTransformAbAttr extends PostSummonAbAttr {
 
     let target: Pokemon;
     if (targets.length > 1) {
-      pokemon.scene.executeWithSeedOffset(() => target = Utils.randSeedItem(targets), pokemon.scene.currentBattle.waveIndex);
+      pokemon.scene.executeWithSeedOffset(() => {
+        // in a double battle, if one of the opposing pokemon is fused the other one will be chosen
+        // if both are fused, then Imposter will fail below
+        if (targets[0].fusionSpecies) {
+          target = targets[1];
+          return;
+        } else if (targets[1].fusionSpecies) {
+          target = targets[0];
+          return;
+        }
+        target = Utils.randSeedItem(targets);
+      }, pokemon.scene.currentBattle.waveIndex);
     } else {
       target = targets[0];
     }
-
     target = target!;
+
+    // transforming from or into fusion pokemon causes various problems (including crashes and save corruption)
+    if (target.fusionSpecies || pokemon.fusionSpecies) {
+      return false;
+    }
+
     pokemon.summonData.speciesForm = target.getSpeciesForm();
-    pokemon.summonData.fusionSpeciesForm = target.getFusionSpeciesForm();
     pokemon.summonData.ability = target.getAbility().id;
     pokemon.summonData.gender = target.getGender();
-    pokemon.summonData.fusionGender = target.getFusionGender();
 
     // Copy all stats (except HP)
     for (const s of EFFECTIVE_STATS) {
diff --git a/src/data/move.ts b/src/data/move.ts
index 071d7fa1e65..753804fe4f1 100644
--- a/src/data/move.ts
+++ b/src/data/move.ts
@@ -6988,6 +6988,9 @@ export class SuppressAbilitiesIfActedAttr extends MoveEffectAttr {
   }
 }
 
+/**
+ * Used by Transform
+ */
 export class TransformAttr extends MoveEffectAttr {
   async apply(user: Pokemon, target: Pokemon, move: Move, args: any[]): Promise<boolean> {
     if (!super.apply(user, target, move, args)) {
@@ -6996,10 +6999,8 @@ export class TransformAttr extends MoveEffectAttr {
 
     const promises: Promise<void>[] = [];
     user.summonData.speciesForm = target.getSpeciesForm();
-    user.summonData.fusionSpeciesForm = target.getFusionSpeciesForm();
     user.summonData.ability = target.getAbility().id;
     user.summonData.gender = target.getGender();
-    user.summonData.fusionGender = target.getFusionGender();
 
     // Power Trick's effect will not preserved after using Transform
     user.removeTag(BattlerTagType.POWER_TRICK);
@@ -8070,7 +8071,8 @@ export function initMoves() {
       .ignoresVirtual(),
     new StatusMove(Moves.TRANSFORM, Type.NORMAL, -1, 10, -1, 0, 1)
       .attr(TransformAttr)
-      .condition((user, target, move) => !target.getTag(BattlerTagType.SUBSTITUTE))
+      // transforming from or into fusion pokemon causes various problems (such as crashes)
+      .condition((user, target, move) => !target.getTag(BattlerTagType.SUBSTITUTE) && !user.fusionSpecies && !target.fusionSpecies)
       .ignoresProtect(),
     new AttackMove(Moves.BUBBLE, Type.WATER, MoveCategory.SPECIAL, 40, 100, 30, 10, 0, 1)
       .attr(StatStageChangeAttr, [ Stat.SPD ], -1)