Minor Roost changes

- Fix 'mon with Flying in type3 but not type1 or type2 is set to
  uninitialized roostTypes.
- Remove unread third roostTypes element.
- Option for Gen IV pure-Flying behavior.

include/battle.h

@@ -611,7 +611,7 @@ struct BattleStruct
     u8 debugBattler;
     u8 magnitudeBasePower;
     u8 presentBasePower;
-    u8 roostTypes[MAX_BATTLERS_COUNT][3];
+    u8 roostTypes[MAX_BATTLERS_COUNT][2];
     u8 savedBattlerTarget;
     bool8 ateBoost[MAX_BATTLERS_COUNT];
     u8 activeAbilityPopUps; // as bits for each battler

include/config/battle.h

@@ -38,6 +38,7 @@
 #define B_STEEL_RESISTANCES         GEN_LATEST // In Gen6+, Steel-type Pokémon are no longer resistant to Dark-type and Ghost-type moves.
 #define B_PRANKSTER_DARK_TYPES      GEN_LATEST // In Gen7+, Prankster-elevated status moves do not affect Dark type Pokémon.
 #define B_SHEER_COLD_IMMUNITY       GEN_LATEST // In Gen7+, Ice-types are immune to Sheer Cold
+#define B_ROOST_PURE_FLYING         GEN_LATEST // In Gen5+, Roost makes pure Flying-types into Normal-type.
 
 // Turn settings
 #define B_BINDING_TURNS             GEN_LATEST // In Gen5+, binding moves last for 4-5 turns instead of 2-5 turns. (With Grip Claw, 7 and 5 turns respectively.)

src/battle_script_commands.c

@@ -4802,22 +4802,24 @@ static void Cmd_setroost(void)
     {
         gBattleStruct->roostTypes[gBattlerAttacker][0] = TYPE_FLYING;
         gBattleStruct->roostTypes[gBattlerAttacker][1] = TYPE_FLYING;
-        gBattleStruct->roostTypes[gBattlerAttacker][2] = TYPE_FLYING;
+#if B_ROOST_PURE_FLYING >= GEN_5
         SET_BATTLER_TYPE(gBattlerAttacker, TYPE_NORMAL);
+#else
+        SET_BATTLER_TYPE(gBattlerAttacker, TYPE_MYSTERY);
+#endif
     }
-    // Dual Type with Flying Type.
-    else if ((gBattleMons[gBattlerAttacker].type1 == TYPE_FLYING && gBattleMons[gBattlerAttacker].type2 != TYPE_FLYING)
-           ||(gBattleMons[gBattlerAttacker].type2 == TYPE_FLYING && gBattleMons[gBattlerAttacker].type1 != TYPE_FLYING))
+    // Dual type with flying type.
+    else if (gBattleMons[gBattlerAttacker].type1 == TYPE_FLYING || gBattleMons[gBattlerAttacker].type2 == TYPE_FLYING)
     {
         gBattleStruct->roostTypes[gBattlerAttacker][0] = gBattleMons[gBattlerAttacker].type1;
         gBattleStruct->roostTypes[gBattlerAttacker][1] = gBattleMons[gBattlerAttacker].type2;
         if (gBattleMons[gBattlerAttacker].type1 == TYPE_FLYING)
             gBattleMons[gBattlerAttacker].type1 = TYPE_MYSTERY;
-        if (gBattleMons[gBattlerAttacker].type2 == TYPE_FLYING)
+        else if (gBattleMons[gBattlerAttacker].type2 == TYPE_FLYING)
             gBattleMons[gBattlerAttacker].type2 = TYPE_MYSTERY;
     }
     // Non-flying type.
-    else if (!IS_BATTLER_OF_TYPE(gBattlerAttacker, TYPE_FLYING))
+    else
     {
         gBattleStruct->roostTypes[gBattlerAttacker][0] = gBattleMons[gBattlerAttacker].type1;
         gBattleStruct->roostTypes[gBattlerAttacker][1] = gBattleMons[gBattlerAttacker].type2;