From 918d45a6232ad2c29f93f655d001c68b12a7b9d8 Mon Sep 17 00:00:00 2001
From: Bassoonian <iasperbassoonian@gmail.com>
Date: Sun, 22 Sep 2024 16:33:17 +0200
Subject: [PATCH] Fix default tera type changing upon evolution/form change
 (#5422)

---
 src/evolution_scene.c | 19 +++++++------------
 src/pokemon.c         |  2 ++
 test/pokemon.c        | 11 ++++++++---
 3 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/src/evolution_scene.c b/src/evolution_scene.c
index 98879430cb37..611949490794 100644
--- a/src/evolution_scene.c
+++ b/src/evolution_scene.c
@@ -545,19 +545,13 @@ static void CB2_TradeEvolutionSceneUpdate(void)
 static void CreateShedinja(u16 preEvoSpecies, struct Pokemon *mon)
 {
     u32 data = 0;
-    #if P_SHEDINJA_BALL >= GEN_4
-        u16 ball = ITEM_POKE_BALL;
-    #endif
+    u16 ball = ITEM_POKE_BALL;
     const struct Evolution *evolutions = GetSpeciesEvolutions(preEvoSpecies);
 
     if (evolutions == NULL)
         return;
 
-    if (evolutions[0].method == EVO_LEVEL_NINJASK && gPlayerPartyCount < PARTY_SIZE
-    #if P_SHEDINJA_BALL >= GEN_4
-        && (CheckBagHasItem(ball, 1))
-    #endif
-    )
+    if (evolutions[0].method == EVO_LEVEL_NINJASK && gPlayerPartyCount < PARTY_SIZE && (P_SHEDINJA_BALL < GEN_4 || CheckBagHasItem(ball, 1)))
     {
         s32 i;
         struct Pokemon *shedinja = &gPlayerParty[gPlayerPartyCount];
@@ -567,10 +561,11 @@ static void CreateShedinja(u16 preEvoSpecies, struct Pokemon *mon)
         SetMonData(&gPlayerParty[gPlayerPartyCount], MON_DATA_NICKNAME, GetSpeciesName(evolutions[1].targetSpecies));
         SetMonData(&gPlayerParty[gPlayerPartyCount], MON_DATA_HELD_ITEM, &data);
         SetMonData(&gPlayerParty[gPlayerPartyCount], MON_DATA_MARKINGS, &data);
-    #if P_SHEDINJA_BALL >= GEN_4
-        SetMonData(&gPlayerParty[gPlayerPartyCount], MON_DATA_POKEBALL, &ball);
-        RemoveBagItem(ball, 1);
-    #endif
+        if (P_SHEDINJA_BALL >= GEN_4)
+        {
+            SetMonData(&gPlayerParty[gPlayerPartyCount], MON_DATA_POKEBALL, &ball);
+            RemoveBagItem(ball, 1);
+        }
 
         for (i = MON_DATA_COOL_RIBBON; i < MON_DATA_COOL_RIBBON + CONTEST_CATEGORIES_COUNT; i++)
             SetMonData(&gPlayerParty[gPlayerPartyCount], i, &data);
diff --git a/src/pokemon.c b/src/pokemon.c
index 0583939a8531..e186ce4d51cd 100644
--- a/src/pokemon.c
+++ b/src/pokemon.c
@@ -2791,6 +2791,8 @@ u32 GetBoxMonData3(struct BoxPokemon *boxMon, s32 field, u8 *data)
             {
                 const u8 *types = gSpeciesInfo[substruct0->species].types;
                 retVal = (boxMon->personality & 0x1) == 0 ? types[0] : types[1];
+                // To avoid this value changing upon form change/evolution, we directly set it for future cases
+                SetBoxMonData(boxMon, MON_DATA_TERA_TYPE, &retVal);
             }
             else
             {
diff --git a/test/pokemon.c b/test/pokemon.c
index 8419b9c7e16f..562b8b10a37b 100644
--- a/test/pokemon.c
+++ b/test/pokemon.c
@@ -325,20 +325,25 @@ TEST("givemon [vars]")
     EXPECT_EQ(GetMonData(&gPlayerParty[0], MON_DATA_TERA_TYPE), TYPE_FIRE);
 }
 
-TEST("checkteratype/setteratype work")
+TEST("checkteratype works")
 {
     CreateMon(&gPlayerParty[0], SPECIES_WOBBUFFET, 100, 0, FALSE, 0, OT_ID_PRESET, 0);
 
     RUN_OVERWORLD_SCRIPT(
         checkteratype 0;
     );
-    EXPECT(VarGet(VAR_RESULT) == TYPE_PSYCHIC);
+    EXPECT_EQ(VarGet(VAR_RESULT), TYPE_PSYCHIC);
+}
+
+TEST("setteratype works")
+{
+    CreateMon(&gPlayerParty[0], SPECIES_WOBBUFFET, 100, 0, FALSE, 0, OT_ID_PRESET, 0);
 
     RUN_OVERWORLD_SCRIPT(
         setteratype TYPE_FIRE, 0;
         checkteratype 0;
     );
-    EXPECT(VarGet(VAR_RESULT) == TYPE_FIRE);
+    EXPECT_EQ(VarGet(VAR_RESULT), TYPE_FIRE);
 }
 
 TEST("createmon [simple]")