Fix in-battle form changes always reverting (#8810)

docs/tutorials/how_to_new_pokemon.md

@@ -1075,7 +1075,8 @@ These tables, unlike the regular form tables, registers how Pokémon can switch
 
 ```c
 #if P_FAMILY_GASTLY
-static const struct FormChange sGengarFormChangeTable[] = {
+static const struct FormChange sGengarFormChangeTable[] =
+{
     {FORM_CHANGE_BATTLE_MEGA_EVOLUTION_ITEM, SPECIES_GENGAR_MEGA, ITEM_GENGARITE},
     {FORM_CHANGE_BATTLE_GIGANTAMAX,          SPECIES_GENGAR_GIGANTAMAX},
     {FORM_CHANGE_TERMINATOR},

src/data/pokemon/species_info/gen_7_families.h

@@ -6932,6 +6932,7 @@ const struct SpeciesInfo gSpeciesInfoGen7[] =
         .levelUpLearnset = sNecrozmaLevelUpLearnset,
         .teachableLearnset = sNecrozmaTeachableLearnset,
         .formSpeciesIdTable = sNecrozmaFormSpeciesIdTable,
+        .formChangeTable = sNecrozmaUltraFormChangeTable,
     },
 #endif //P_ULTRA_BURST_FORMS
 #endif //P_FUSION_FORMS

src/data/pokemon/species_info/gen_8_families.h

@@ -7390,6 +7390,7 @@ const struct SpeciesInfo gSpeciesInfoGen8[] =
         .levelUpLearnset = sUrshifuSingleStrikeLevelUpLearnset,
         .teachableLearnset = sUrshifuSingleStrikeTeachableLearnset,
         .formSpeciesIdTable = sUrshifuFormSpeciesIdTable,
+        .formChangeTable = sUrshifuSingleStrikeFormChangeTable,
     },
 #endif //P_GIGANTAMAX_FORMS
 
@@ -7517,6 +7518,7 @@ const struct SpeciesInfo gSpeciesInfoGen8[] =
         .levelUpLearnset = sUrshifuRapidStrikeLevelUpLearnset,
         .teachableLearnset = sUrshifuRapidStrikeTeachableLearnset,
         .formSpeciesIdTable = sUrshifuFormSpeciesIdTable,
+        .formChangeTable = sUrshifuRapidStrikeFormChangeTable,
     },
 #endif //P_GIGANTAMAX_FORMS
 #endif //P_FAMILY_KUBFU

src/pokemon.c

@@ -7154,10 +7154,19 @@ bool32 TryFormChange(u32 monId, enum BattleSide side, enum FormChanges method)
     u32 currentSpecies = GetMonData(&party[monId], MON_DATA_SPECIES);
     u32 targetSpecies = GetFormChangeTargetSpecies(&party[monId], method, 0);
 
-    if (targetSpecies == currentSpecies && gBattleStruct != NULL && gBattleStruct->partyState[side][monId].changedSpecies != SPECIES_NONE)
+    // If the battle ends, and there's not a specified species to change back to,,
+    // use the species at the start of the battle.
+    if (targetSpecies == SPECIES_NONE
+        && gBattleStruct != NULL
+        && gBattleStruct->partyState[side][monId].changedSpecies != SPECIES_NONE
+        // This is added to prevent FORM_CHANGE_END_BATTLE_ENVIRONMENT from omitting move changes
+        // at the end of the battle, as it was being counting as a successful form change.
+        && method == FORM_CHANGE_END_BATTLE)
+    {
         targetSpecies = gBattleStruct->partyState[side][monId].changedSpecies;
+    }
 
-    if (targetSpecies != currentSpecies)
+    if (targetSpecies != currentSpecies && targetSpecies != SPECIES_NONE)
     {
         TryToSetBattleFormChangeMoves(&party[monId], method);
         SetMonData(&party[monId], MON_DATA_SPECIES, &targetSpecies);
@@ -7367,7 +7376,7 @@ void UpdateDaysPassedSinceFormChange(u16 days)
         {
             u32 targetSpecies = GetFormChangeTargetSpecies(mon, FORM_CHANGE_DAYS_PASSED, 0);
 
-            if (targetSpecies != currentSpecies)
+            if (targetSpecies != currentSpecies && targetSpecies != SPECIES_NONE)
             {
                 SetMonData(mon, MON_DATA_SPECIES, &targetSpecies);
                 CalculateMonStats(mon);

test/battle/form_change/end_battle.c

@@ -90,7 +90,6 @@ SINGLE_BATTLE_TEST("Palafin returns to Zero form upon battle end")
 
 SINGLE_BATTLE_TEST("Shaymin retains Land form if it was frozen or frostbitten in battle")
 {
-    KNOWN_FAILING; // changedSpecies is forcing the return to Sky Form
     GIVEN {
         ASSUME(MoveHasAdditionalEffect(MOVE_POWDER_SNOW, MOVE_EFFECT_FREEZE_OR_FROSTBITE));
         PLAYER(SPECIES_SHAYMIN_SKY);

test/species.c

@@ -59,6 +59,23 @@ TEST("Form change tables contain only forms in the form species ID table")
     }
 }
 
+TEST("Forms have the appropriate species form changes")
+{
+    u32 i;
+    u32 species = SPECIES_NONE;
+
+    for (i = 0; i < NUM_SPECIES; i++)
+    {
+        if (gSpeciesInfo[i].isMegaEvolution
+            || gSpeciesInfo[i].isGigantamax
+            || gSpeciesInfo[i].isUltraBurst)
+        {
+            PARAMETRIZE_LABEL("%S", gSpeciesInfo[i].speciesName) { species = i; }
+        }
+    }
+        EXPECT(DoesSpeciesHaveFormChangeMethod(species, FORM_CHANGE_END_BATTLE));
+    }
+
 TEST("Form change targets have the appropriate species flags")
 {
     u32 i;