From c90e6952f32466ed165565c561cbf862fdb90d74 Mon Sep 17 00:00:00 2001
From: grintoul <166724814+grintoul1@users.noreply.github.com>
Date: Tue, 28 Oct 2025 18:26:10 +0000
Subject: [PATCH] Fix Ally Switch being useable in Frontier Link Multi battles
 (#8059)

Co-authored-by: Alex <93446519+AlexOn1ine@users.noreply.github.com>
---
 include/battle_util.h        | 1 +
 include/constants/battle.h   | 1 +
 src/battle_script_commands.c | 4 +---
 src/battle_tower.c           | 2 +-
 src/battle_util.c            | 9 +++++++++
 5 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/include/battle_util.h b/include/battle_util.h
index 3531f0eb6b..8601c792f6 100644
--- a/include/battle_util.h
+++ b/include/battle_util.h
@@ -414,5 +414,6 @@ bool32 CanMoveSkipAccuracyCalc(u32 battlerAtk, u32 battlerDef, u32 abilityAtk, u
 u32 GetTotalAccuracy(u32 battlerAtk, u32 battlerDef, u32 move, u32 atkAbility, u32 defAbility, u32 atkHoldEffect, u32 defHoldEffect);
 bool32 IsSemiInvulnerable(u32 battler, enum SemiInvulnerableExclusion excludeCommander);
 bool32 BreaksThroughSemiInvulnerablity(u32 battler, u32 move);
+bool32 HasPartnerTrainer(u32 battler);
 
 #endif // GUARD_BATTLE_UTIL_H
diff --git a/include/constants/battle.h b/include/constants/battle.h
index 825487f24e..012b8986ef 100644
--- a/include/constants/battle.h
+++ b/include/constants/battle.h
@@ -99,6 +99,7 @@ enum BattlerId
 #define RECORDED_WILD_BATTLE ((gBattleTypeFlags & BATTLE_TYPE_RECORDED) && !(gBattleTypeFlags & (BATTLE_TYPE_TRAINER | BATTLE_TYPE_FRONTIER)))
 #define BATTLE_TWO_VS_ONE_OPPONENT ((gBattleTypeFlags & BATTLE_TYPE_INGAME_PARTNER && TRAINER_BATTLE_PARAM.opponentB == 0xFFFF))
 #define BATTLE_TYPE_HAS_AI          (BATTLE_TYPE_TRAINER | BATTLE_TYPE_FIRST_BATTLE | BATTLE_TYPE_SAFARI | BATTLE_TYPE_ROAMER | BATTLE_TYPE_INGAME_PARTNER)
+#define BATTLE_TYPE_PLAYER_HAS_PARTNER      (BATTLE_TYPE_MULTI | BATTLE_TYPE_INGAME_PARTNER | BATTLE_TYPE_TOWER_LINK_MULTI)
 
 // Battle Outcome defines
 #define B_OUTCOME_WON                  1
diff --git a/src/battle_script_commands.c b/src/battle_script_commands.c
index b8c12c1c5e..223a4bd382 100755
--- a/src/battle_script_commands.c
+++ b/src/battle_script_commands.c
@@ -15711,9 +15711,7 @@ void BS_TryAllySwitch(void)
 {
     NATIVE_ARGS(const u8 *failInstr);
 
-    if (!IsBattlerAlive(BATTLE_PARTNER(gBattlerAttacker))
-     || (GetBattlerSide(gBattlerAttacker) == B_SIDE_PLAYER && gBattleTypeFlags & BATTLE_TYPE_INGAME_PARTNER)
-     || (GetBattlerSide(gBattlerAttacker) == B_SIDE_OPPONENT && gBattleTypeFlags & BATTLE_TYPE_TWO_OPPONENTS))
+    if (!IsBattlerAlive(BATTLE_PARTNER(gBattlerAttacker)) || HasPartnerTrainer(gBattlerAttacker))
     {
         gBattlescriptCurrInstr = cmd->failInstr;
     }
diff --git a/src/battle_tower.c b/src/battle_tower.c
index e215c259a4..a03f0a130b 100644
--- a/src/battle_tower.c
+++ b/src/battle_tower.c
@@ -1987,7 +1987,7 @@ void DoSpecialTrainerBattle(void)
             gBattleTypeFlags |= BATTLE_TYPE_DOUBLE | BATTLE_TYPE_INGAME_PARTNER | BATTLE_TYPE_MULTI | BATTLE_TYPE_TWO_OPPONENTS;
             break;
         case FRONTIER_MODE_LINK_MULTIS:
-            gBattleTypeFlags |= BATTLE_TYPE_DOUBLE | BATTLE_TYPE_LINK | BATTLE_TYPE_MULTI | BATTLE_TYPE_TOWER_LINK_MULTI;
+            gBattleTypeFlags |= BATTLE_TYPE_DOUBLE | BATTLE_TYPE_LINK | BATTLE_TYPE_MULTI | BATTLE_TYPE_TOWER_LINK_MULTI | BATTLE_TYPE_TWO_OPPONENTS;
             FillFrontierTrainersParties(FRONTIER_MULTI_PARTY_SIZE);
             break;
         }
diff --git a/src/battle_util.c b/src/battle_util.c
index 8700fe2b2e..2e2f18cbc9 100644
--- a/src/battle_util.c
+++ b/src/battle_util.c
@@ -11907,3 +11907,12 @@ bool32 BreaksThroughSemiInvulnerablity(u32 battler, u32 move)
 
     return FALSE;
 }
+
+bool32 HasPartnerTrainer(u32 battler)
+{
+    if ((GetBattlerSide(battler) == B_SIDE_PLAYER && gBattleTypeFlags & BATTLE_TYPE_PLAYER_HAS_PARTNER)
+     || (GetBattlerSide(battler) == B_SIDE_OPPONENT && gBattleTypeFlags & BATTLE_TYPE_TWO_OPPONENTS))
+        return TRUE;
+    else
+        return FALSE;
+}