Fix AI's right slot switching-in too early (#4851)

* apply safe switching to trainer doubles battles - with a config

* get rid of the config

* make it compile

data/battle_scripts_1.s

@@ -5407,7 +5407,7 @@ BattleScript_GiveExp::
 
 BattleScript_HandleFaintedMon::
 	setbyte sSHIFT_SWITCHED, 0
-	checkteamslost BattleScript_LinkHandleFaintedMonMultiple
+	checkteamslost BattleScript_HandleFaintedMonMultiple
 	jumpifbyte CMP_NOT_EQUAL, gBattleOutcome, 0, BattleScript_FaintedMonEnd
 	jumpifbattletype BATTLE_TYPE_TRAINER | BATTLE_TYPE_DOUBLE, BattleScript_FaintedMonTryChoose
 	jumpifword CMP_NO_COMMON_BITS, gHitMarker, HITMARKER_PLAYER_FAINTED, BattleScript_FaintedMonTryChoose
@@ -5488,13 +5488,13 @@ BattleScript_FaintedMonShiftSwitched:
 	copybyte gBattlerTarget, sSAVED_BATTLER
 	goto BattleScript_FaintedMonSendOutNewEnd
 
-BattleScript_LinkHandleFaintedMonMultiple::
+BattleScript_HandleFaintedMonMultiple::
-	openpartyscreen BS_FAINTED_LINK_MULTIPLE_1, BattleScript_LinkHandleFaintedMonMultipleStart
+	openpartyscreen BS_FAINTED_MULTIPLE_1, BattleScript_HandleFaintedMonMultipleStart
-BattleScript_LinkHandleFaintedMonMultipleStart::
+BattleScript_HandleFaintedMonMultipleStart::
 	switchhandleorder BS_FAINTED, 0
-	openpartyscreen BS_FAINTED_LINK_MULTIPLE_2, BattleScript_LinkHandleFaintedMonMultipleEnd
+	openpartyscreen BS_FAINTED_MULTIPLE_2, BattleScript_HandleFaintedMonMultipleEnd
 	switchhandleorder BS_FAINTED, 0
-BattleScript_LinkHandleFaintedMonLoop::
+BattleScript_HandleFaintedMonLoop::
 	switchhandleorder BS_FAINTED, 3
 	drawpartystatussummary BS_FAINTED
 	getswitchedmondata BS_FAINTED
@@ -5506,9 +5506,9 @@ BattleScript_LinkHandleFaintedMonLoop::
 	hidepartystatussummary BS_FAINTED
 	switchinanim BS_FAINTED, FALSE
 	waitstate
-	switchineffects BS_FAINTED_LINK_MULTIPLE_1
+	switchineffects BS_FAINTED_MULTIPLE_1
-	jumpifbytenotequal gBattlerFainted, gBattlersCount, BattleScript_LinkHandleFaintedMonLoop
+	jumpifbytenotequal gBattlerFainted, gBattlersCount, BattleScript_HandleFaintedMonLoop
-BattleScript_LinkHandleFaintedMonMultipleEnd::
+BattleScript_HandleFaintedMonMultipleEnd::
 	end2
 
 BattleScript_LocalTrainerBattleWon::

include/constants/battle_script_commands.h

@@ -63,8 +63,8 @@
 #define BS_EFFECT_BATTLER           2
 #define BS_FAINTED                  3
 #define BS_ATTACKER_WITH_PARTNER    4 // for Cmd_updatestatusicon
-#define BS_FAINTED_LINK_MULTIPLE_1  5 // for openpartyscreen
+#define BS_FAINTED_MULTIPLE_1       5 // for openpartyscreen
-#define BS_FAINTED_LINK_MULTIPLE_2  6 // for openpartyscreen
+#define BS_FAINTED_MULTIPLE_2       6 // for openpartyscreen
 #define BS_BATTLER_0                7
 #define BS_ATTACKER_SIDE            8 // for Cmd_jumpifability
 #define BS_TARGET_SIDE              9 // for Cmd_jumpifability

src/battle_script_commands.c

@@ -4633,7 +4633,7 @@ bool32 NoAliveMonsForEitherParty(void)
     return (NoAliveMonsForPlayer() || NoAliveMonsForOpponent());
 }
 
-// For battles that aren't BATTLE_TYPE_LINK or BATTLE_TYPE_RECORDED_LINK, the only thing this
+// For battles that aren't BATTLE_TYPE_LINK or BATTLE_TYPE_RECORDED_LINK or double trainer battles, the only thing this
 // command does is check whether the player has won/lost by totaling each team's HP. It then
 // sets gBattleOutcome accordingly, if necessary.
 static void Cmd_checkteamslost(void)
@@ -4649,10 +4649,16 @@ static void Cmd_checkteamslost(void)
     if (NoAliveMonsForOpponent())
         gBattleOutcome |= B_OUTCOME_WON;
 
-    // For link battles that haven't ended, count number of empty battler spots
+    // Fair switching - everyone has to switch in most at the same time, without knowing which pokemon the other trainer selected.
-    // In link multi battles, jump to pointer if more than 1 spot empty
+    // In vanilla Emerald this was only used for link battles, in expansion it's also used for regular trainers in double battles.
+    // For battles that haven't ended, count number of empty battler spots
+    // In multi battles, jump to pointer if more than 1 spot empty
     // In non-multi battles, jump to pointer if 1 spot is missing on both sides
-    if (gBattleOutcome == 0 && (gBattleTypeFlags & (BATTLE_TYPE_LINK | BATTLE_TYPE_RECORDED_LINK)))
+    if (gBattleOutcome == 0
+        && (((gBattleTypeFlags & (BATTLE_TYPE_LINK | BATTLE_TYPE_RECORDED_LINK)))
+              || ((gBattleTypeFlags & BATTLE_TYPE_TRAINER) && (gBattleTypeFlags & BATTLE_TYPE_DOUBLE))
+            )
+        )
     {
         s32 i, emptyPlayerSpots, emptyOpponentSpots;
 
@@ -6769,7 +6775,7 @@ static void Cmd_openpartyscreen(void)
     u32 i, battler = 0;
     const u8 *failInstr = cmd->failInstr;
 
-    if (cmd->battler == BS_FAINTED_LINK_MULTIPLE_1)
+    if (cmd->battler == BS_FAINTED_MULTIPLE_1)
     {
         if ((gBattleTypeFlags & BATTLE_TYPE_MULTI) || !(gBattleTypeFlags & BATTLE_TYPE_DOUBLE))
         {
@@ -6924,7 +6930,7 @@ static void Cmd_openpartyscreen(void)
         }
         gBattlescriptCurrInstr = cmd->nextInstr;
     }
-    else if (cmd->battler == BS_FAINTED_LINK_MULTIPLE_2)
+    else if (cmd->battler == BS_FAINTED_MULTIPLE_2)
     {
         if (!(gBattleTypeFlags & BATTLE_TYPE_MULTI))
         {
@@ -7307,7 +7313,7 @@ static void Cmd_switchineffects(void)
             gBattleStruct->hpOnSwitchout[GetBattlerSide(i)] = gBattleMons[i].hp;
         }
 
-        if (cmd->battler == BS_FAINTED_LINK_MULTIPLE_1)
+        if (cmd->battler == BS_FAINTED_MULTIPLE_1)
         {
             u32 hitmarkerFaintBits = gHitMarker >> 28;
 

src/battle_util.c

@@ -958,11 +958,11 @@ u8 GetBattlerForBattleScript(u8 caseId)
     case BS_FAINTED:
         ret = gBattlerFainted;
         break;
-    case BS_FAINTED_LINK_MULTIPLE_1:
+    case BS_FAINTED_MULTIPLE_1:
         ret = gBattlerFainted;
         break;
     case BS_ATTACKER_WITH_PARTNER:
-    case BS_FAINTED_LINK_MULTIPLE_2:
+    case BS_FAINTED_MULTIPLE_2:
     case BS_ATTACKER_SIDE:
     case BS_TARGET_SIDE:
     case BS_PLAYER1: