Fix substitute/defog interactions (#8418)

data/battle_scripts_1.s

@@ -1493,12 +1493,17 @@ BattleScript_EffectHitEnemyHealAlly::
 BattleScript_EffectDefog::
 	setstatchanger STAT_EVASION, 1, TRUE
 	attackcanceler
+	jumpifgenconfiglowerthan CONFIG_DEFOG_EFFECT_CLEARING, GEN_5, BattleScript_DefogAfterSubstituteCheck
 	jumpifsubstituteblocks BattleScript_DefogIfCanClearHazards
+BattleScript_DefogAfterSubstituteCheck:
 	jumpifstat BS_TARGET, CMP_NOT_EQUAL, STAT_EVASION, MIN_STAT_STAGE, BattleScript_DefogWorks
 BattleScript_DefogIfCanClearHazards:
 	trydefog FALSE, BattleScript_ButItFailed
 BattleScript_DefogWorks:
 	accuracycheck BattleScript_MoveMissedPause, ACC_CURR_MOVE
+	jumpifgenconfiglowerthan CONFIG_DEFOG_EFFECT_CLEARING, GEN_5, BattleScript_DefogWorksAfterSubstituteCheck
+	jumpifsubstituteblocks BattleScript_DefogTryHazardsWithAnim
+BattleScript_DefogWorksAfterSubstituteCheck:
 	statbuffchange BS_TARGET, STAT_CHANGE_ALLOW_PTR | STAT_CHANGE_ONLY_CHECKING, BattleScript_DefogTryHazardsWithAnim
 	jumpifbyte CMP_LESS_THAN, cMULTISTRING_CHOOSER, B_MSG_STAT_WONT_CHANGE, BattleScript_DefogDoAnim
 	jumpifbyte CMP_EQUAL, cMULTISTRING_CHOOSER, B_MSG_STAT_CHANGE_EMPTY, BattleScript_DefogTryHazardsWithAnim
@@ -1508,7 +1513,9 @@ BattleScript_DefogWorks:
 BattleScript_DefogDoAnim::
 	attackanimation
 	waitanimation
+	call BattleScript_SwapFromSubstitute
 	statbuffchange BS_TARGET, STAT_CHANGE_ALLOW_PTR, BattleScript_DefogTryHazards
+	call BattleScript_SwapToSubstitute
 BattleScript_DefogPrintString::
 	printfromtable gStatDownStringIds
 	waitmessage B_WAIT_TIME_LONG

include/config/battle.h

@@ -111,7 +111,7 @@
 #define B_BURN_HIT_THAW             GEN_LATEST // In Gen6+, damaging moves with a chance of burn will thaw the target, regardless if they're fire-type moves or not.
 #define B_HEALING_WISH_SWITCH       GEN_LATEST // In Gen5+, the mon receiving Healing Wish is sent out at the end of the turn.
                                                // Additionally, in gen8+ the Healing Wish's effect will be stored until the user switches into a statused or hurt mon.
-#define B_DEFOG_EFFECT_CLEARING     GEN_LATEST // In Gen6+, Defog clears Spikes, Toxic Spikes, Stealth Rock and Sticky Web from both sides. In Gen8+, Defog also clears active Terrain.
+#define B_DEFOG_EFFECT_CLEARING     GEN_LATEST // In Gen5+, Defog does not lower Evasion of target behind Subsitute. In Gen6+, Defog clears Spikes, Toxic Spikes, Stealth Rock and Sticky Web from both sides. In Gen8+, Defog also clears active Terrain.
 #define B_STOCKPILE_RAISES_DEFS     GEN_LATEST // In Gen4+, Stockpile also raises Defense and Sp. Defense stats. Once Spit Up / Swallow is used, these stat changes are lost.
 #define B_TRANSFORM_SHINY           GEN_LATEST // In Gen4+, Transform will copy the shiny state of the opponent instead of maintaining its own shiny state.
 #define B_TRANSFORM_FORM_CHANGES    GEN_LATEST // In Gen5+, Transformed Pokemon cannot change forms.

src/battle_gfx_sfx_util.c

@@ -557,6 +557,7 @@ static bool8 ShouldAnimBeDoneRegardlessOfSubstitute(u8 animId)
     case B_ANIM_SNOW_CONTINUES:
     case B_ANIM_FOG_CONTINUES:
     case B_ANIM_SNATCH_MOVE:
+    case B_ANIM_STATS_CHANGE:
         return TRUE;
     default:
         return FALSE;

src/battle_script_commands.c

@@ -9392,14 +9392,20 @@ static bool32 TryDefogClear(u32 battlerAtk, bool32 clear)
         }
         if (gBattleWeather & B_WEATHER_FOG)
         {
-            gBattleWeather &= ~B_WEATHER_FOG;
+            if (clear)
-            BattleScriptCall(BattleScript_FogEnded_Ret);
+            {
+                gBattleWeather &= ~B_WEATHER_FOG;
+                BattleScriptCall(BattleScript_FogEnded_Ret);
+            }
             return TRUE;
         }
         if (GetConfig(CONFIG_DEFOG_EFFECT_CLEARING) >= GEN_8 && (gFieldStatuses & STATUS_FIELD_TERRAIN_ANY))
         {
-            RemoveAllTerrains();
+            if (clear)
-            BattleScriptCall(BattleScript_TerrainEnds_Ret);
+            {
+                RemoveAllTerrains();
+                BattleScriptCall(BattleScript_TerrainEnds_Ret);
+            }
             return TRUE;
         }
     }

test/battle/move_effect/defog.c

@@ -34,20 +34,92 @@ SINGLE_BATTLE_TEST("Defog lowers evasiveness by 1 stage")
     }
 }
 
-SINGLE_BATTLE_TEST("Defog does not lower evasiveness if target behind Substitute")
+SINGLE_BATTLE_TEST("Defog fails if target has minimum evasion stat change")
 {
     GIVEN {
+        PLAYER(SPECIES_WOBBUFFET);
+        OPPONENT(SPECIES_WOBBUFFET) {Ability(ABILITY_SIMPLE);};
+    } WHEN {
+        TURN { MOVE(player, MOVE_DEFOG); }
+        TURN { MOVE(player, MOVE_DEFOG); }
+        TURN { MOVE(player, MOVE_DEFOG); }
+        TURN { MOVE(player, MOVE_DEFOG); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_DEFOG, player);
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+        MESSAGE("The opposing Wobbuffet's evasiveness harshly fell!");
+        MESSAGE("But it failed!");
+    }
+}
+
+SINGLE_BATTLE_TEST("Defog lowers evasiveness of target behind Substitute (Gen4-)")
+{
+    GIVEN {
+        WITH_CONFIG(CONFIG_DEFOG_EFFECT_CLEARING, GEN_4);
         PLAYER(SPECIES_WOBBUFFET) { Speed(4); }
         OPPONENT(SPECIES_WOBBUFFET) { Speed(5); }
     } WHEN {
         TURN { MOVE(opponent, MOVE_SUBSTITUTE); MOVE(player, MOVE_DEFOG); }
     } SCENE {
         MESSAGE("The opposing Wobbuffet used Substitute!");
+        NOT MESSAGE("But it failed!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_DEFOG, player);
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+        MESSAGE("The opposing Wobbuffet's evasiveness fell!");
+    }
+}
+
+SINGLE_BATTLE_TEST("Defog fails if target has minimum evasion stat change behind Substitute (Gen4-)")
+{
+    GIVEN {
+        WITH_CONFIG(CONFIG_DEFOG_EFFECT_CLEARING, GEN_4);
+        PLAYER(SPECIES_WOBBUFFET) { Speed(4); }
+        OPPONENT(SPECIES_WOBBUFFET) { Speed(5); Ability(ABILITY_SIMPLE);}
+    } WHEN {
+        TURN { MOVE(opponent, MOVE_SUBSTITUTE); MOVE(player, MOVE_DEFOG); }
+        TURN { MOVE(player, MOVE_DEFOG); }
+        TURN { MOVE(player, MOVE_DEFOG); }
+        TURN { MOVE(player, MOVE_DEFOG); }
+    } SCENE {
+        MESSAGE("The opposing Wobbuffet used Substitute!");
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_DEFOG, player);
+        ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+        MESSAGE("The opposing Wobbuffet's evasiveness harshly fell!");
         MESSAGE("But it failed!");
-        NONE_OF {
+    }
-            ANIMATION(ANIM_TYPE_MOVE, MOVE_DEFOG, player);
+}
-            ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+
-            MESSAGE("The opposing Wobbuffet's evasiveness fell!");
+SINGLE_BATTLE_TEST("Defog does not lower evasiveness if target behind Substitute (Gen5+)")
+{
+    u32 move;
+
+    PARAMETRIZE { move = MOVE_LIGHT_SCREEN; }
+    PARAMETRIZE { move = MOVE_CELEBRATE; }
+
+    GIVEN {
+        ASSUME(CONFIG_DEFOG_EFFECT_CLEARING >= GEN_5);
+        PLAYER(SPECIES_WOBBUFFET) { Speed(4); }
+        OPPONENT(SPECIES_WOBBUFFET) { Speed(5); }
+    } WHEN {
+        TURN { MOVE(opponent, move); }
+        TURN { MOVE(opponent, MOVE_SUBSTITUTE); MOVE(player, MOVE_DEFOG); }
+    } SCENE {
+        MESSAGE("The opposing Wobbuffet used Substitute!");
+        if (move == MOVE_CELEBRATE)
+        {
+            MESSAGE("But it failed!");
+            NONE_OF {
+                ANIMATION(ANIM_TYPE_MOVE, MOVE_DEFOG, player);
+                ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+                MESSAGE("The opposing Wobbuffet's evasiveness fell!");
+            }
+        }
+        else
+        {
+            NONE_OF {
+                ANIMATION(ANIM_TYPE_GENERAL, B_ANIM_STATS_CHANGE, opponent);
+                MESSAGE("The opposing Wobbuffet's evasiveness fell!");
+            }
         }
     }
 }
@@ -423,7 +495,6 @@ SINGLE_BATTLE_TEST("Defog is used on the correct side if opposing mon is behind
         ANIMATION(ANIM_TYPE_MOVE, MOVE_SUBSTITUTE, opponent);
         MESSAGE("Wobbuffet used Defog!");
         ANIMATION(ANIM_TYPE_MOVE, MOVE_DEFOG, player);
-        MESSAGE("The opposing Wobbuffet's evasiveness fell!");
         MESSAGE("The opposing team's Light Screen wore off!");
     }
 }