From 62f01e89d779abd60b79aa87211636bffb773a38 Mon Sep 17 00:00:00 2001
From: BuffelSaft <buffalojuice@gmail.com>
Date: Tue, 23 Nov 2021 00:46:43 +1300
Subject: [PATCH] Fix Burmy form change

Wasn't properly tracking if Burmy had appeared in battle; gSentPokesToOpponent is used only for exp calculation and is cleared when an opponent faints, so a new var was needed.
---
 include/battle.h             | 1 +
 src/battle_main.c            | 4 ++++
 src/battle_script_commands.c | 5 ++++-
 src/battle_util.c            | 6 +++---
 4 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/battle.h b/include/battle.h
index 5658f603cf..9c04a24eb5 100644
--- a/include/battle.h
+++ b/include/battle.h
@@ -616,6 +616,7 @@ struct BattleStruct
     u8 blunderPolicy:1; // should blunder policy activate
     u8 ballSpriteIds[2];    // item gfx, window gfx
     u8 stickyWebUser;
+    u8 appearedInBattle; // Bitfield to track which Pokemon appeared in battle. Used for Burmy's form change
 };
 
 #define GET_MOVE_TYPE(move, typeArg)                        \
diff --git a/src/battle_main.c b/src/battle_main.c
index 84f66d6ded..1a4117d4fe 100644
--- a/src/battle_main.c
+++ b/src/battle_main.c
@@ -2937,6 +2937,7 @@ static void BattleStartClearSetData(void)
     gBattleStruct->mega.triggerSpriteId = 0xFF;
     
     gBattleStruct->stickyWebUser = 0xFF;
+    gBattleStruct->appearedInBattle = 0;
     
     for (i = 0; i < PARTY_SIZE; i++)
     {
@@ -3577,6 +3578,9 @@ static void TryDoEventsBeforeFirstTurn(void)
         *(gBattleStruct->monToSwitchIntoId + i) = PARTY_SIZE;
         gChosenActionByBattler[i] = B_ACTION_NONE;
         gChosenMoveByBattler[i] = MOVE_NONE;
+        // Record party slots of player's mons that appeared in battle
+        if (!IsBattlerAIControlled(i))
+            gBattleStruct->appearedInBattle |= gBitTable[gBattlerPartyIndexes[i]];
     }
     TurnValuesCleanUp(FALSE);
     SpecialStatusesClear();
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index 4ae42cb487..116316b16f 100644
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -6176,7 +6176,10 @@ static void Cmd_switchineffects(void)
 
     gHitMarker &= ~(HITMARKER_FAINTED(gActiveBattler));
     gSpecialStatuses[gActiveBattler].flag40 = 0;
-    
+
+    if (!IsBattlerAIControlled(gActiveBattler))
+        gBattleStruct->appearedInBattle |= gBitTable[gBattlerPartyIndexes[gActiveBattler]];
+
     // Neutralizing Gas announces itself before hazards
     if (gBattleMons[gActiveBattler].ability == ABILITY_NEUTRALIZING_GAS && gSpecialStatuses[gActiveBattler].announceNeutralizingGas == 0)
     {
diff --git a/src/battle_util.c b/src/battle_util.c
index 7e2320500c..f7e72ae404 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -9769,13 +9769,13 @@ bool32 TryRoomService(u8 battlerId)
 void DoBurmyFormChange(u32 monId)
 {
     u16 newSpecies, currSpecies;
-    s32 sentIn;
     struct Pokemon *party = gPlayerParty;
 
-    sentIn = gSentPokesToOpponent[(gBattlerFainted & 2) >> 1];
     currSpecies = GetMonData(&party[monId], MON_DATA_SPECIES, NULL);
 
-    if ((GET_BASE_SPECIES_ID(currSpecies) == SPECIES_BURMY) && (gBitTable[monId] & sentIn))
+    if ((GET_BASE_SPECIES_ID(currSpecies) == SPECIES_BURMY) 
+        && (gBattleStruct->appearedInBattle & gBitTable[monId]) // Burmy appeared in battle
+        && GetMonData(&party[monId], MON_DATA_HP, NULL) != 0) // Burmy isn't fainted
     {
         switch (gBattleTerrain)
         {