Fix incorrect player berry animation on opponent’s low-HP heal at battle start (#9198)

src/battle_main.c

@@ -3890,6 +3890,7 @@ static void TryDoEventsBeforeFirstTurn(void)
         while (gBattleStruct->switchInBattlerCounter < gBattlersCount) // From fastest to slowest
         {
             u32 battler = gBattlerByTurnOrder[gBattleStruct->switchInBattlerCounter++];
+            gBattlerAttacker = battler;
             if (ItemBattleEffects(battler, 0, GetBattlerHoldEffect(battler), IsOnSwitchInFirstTurnActivation))
                 return;
         }

test/battle/ability/dazzling.c

@@ -163,8 +163,8 @@ SINGLE_BATTLE_TEST("Dazzling, Queenly Majesty and Armor Tail do not block Teatim
     GIVEN {
         ASSUME(GetMoveEffect(MOVE_TEATIME) == EFFECT_TEATIME);
         ASSUME(GetItemHoldEffect(ITEM_ORAN_BERRY) == HOLD_EFFECT_RESTORE_HP);
-        PLAYER(SPECIES_MURKROW) { Ability(ABILITY_PRANKSTER); Item(ITEM_ORAN_BERRY); HP(1); MaxHP(100); }
-        OPPONENT(species) { Ability(ability); Item(ITEM_ORAN_BERRY); HP(1); MaxHP(100); }
+        PLAYER(SPECIES_MURKROW) { Ability(ABILITY_PRANKSTER); Item(ITEM_ORAN_BERRY); HP(60); MaxHP(100); }
+        OPPONENT(species) { Ability(ability); Item(ITEM_ORAN_BERRY); HP(60); MaxHP(100); }
     } WHEN {
         TURN { MOVE(player, MOVE_TEATIME); }
     } SCENE {

test/battle/hold_effect/restore_hp.c

@@ -82,3 +82,16 @@ SINGLE_BATTLE_TEST("Sitrus Berry restores HP immediately after Leech Seed damage
         HP_BAR(player);
     }
 }
+
+SINGLE_BATTLE_TEST("Healing berry animates on the correct battler at battle start")
+{
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET);
+        OPPONENT(SPECIES_WOBBUFFET) { HP(1); MaxHP(400); Item(ITEM_ORAN_BERRY); }
+    } WHEN {
+        TURN {  }
+    } SCENE {
+        NOT ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_HELD_ITEM_EFFECT, player);
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_HELD_ITEM_EFFECT, opponent);
+    }
+}