fixed issue with Kruphix, God of Horizons and Horizon Stone causing endless replacement effect loop

Mage.Sets/src/mage/cards/h/HorizonStone.java

@@ -2,14 +2,12 @@ package mage.cards.h;
 
 import mage.abilities.Ability;
 import mage.abilities.common.SimpleStaticAbility;
-import mage.abilities.effects.ReplacementEffectImpl;
+import mage.abilities.effects.ContinuousEffectImpl;
 import mage.cards.CardImpl;
 import mage.cards.CardSetInfo;
-import mage.constants.CardType;
+import mage.constants.*;
-import mage.constants.Duration;
-import mage.constants.Outcome;
 import mage.game.Game;
-import mage.game.events.GameEvent;
+import mage.players.Player;
 
 import java.util.UUID;
 
@@ -35,11 +33,11 @@ public final class HorizonStone extends CardImpl {
     }
 }
 
-class HorizonStoneEffect extends ReplacementEffectImpl {
+class HorizonStoneEffect extends ContinuousEffectImpl {
 
     HorizonStoneEffect() {
-        super(Duration.WhileOnBattlefield, Outcome.Benefit);
+        super(Duration.WhileOnBattlefield, Layer.RulesEffects, SubLayer.NA, Outcome.Benefit);
-        staticText = "If you would lose unspent mana, that mana becomes colorless instead.";
+        staticText = "if you would lose unspent mana, that mana becomes colorless instead";
     }
 
     private HorizonStoneEffect(final HorizonStoneEffect effect) {
@@ -53,21 +51,10 @@ class HorizonStoneEffect extends ReplacementEffectImpl {
 
     @Override
     public boolean apply(Game game, Ability source) {
-        return false;
+        Player player = game.getPlayer(source.getControllerId());
+        if (player != null) {
+            player.getManaPool().setManaBecomesColorless(true);
         }
-
-    @Override
-    public boolean replaceEvent(GameEvent event, Ability source, Game game) {
         return true;
     }
-
-    @Override
-    public boolean checksEventType(GameEvent event, Game game) {
-        return event.getType() == GameEvent.EventType.EMPTY_MANA_POOL;
-    }
-
-    @Override
-    public boolean applies(GameEvent event, Ability source, Game game) {
-        return event.getPlayerId().equals(source.getControllerId());
-    }
 }

Mage.Sets/src/mage/cards/k/KruphixGodOfHorizons.java

@@ -4,7 +4,7 @@ import mage.MageInt;
 import mage.abilities.Ability;
 import mage.abilities.common.SimpleStaticAbility;
 import mage.abilities.dynamicvalue.common.DevotionCount;
-import mage.abilities.effects.ReplacementEffectImpl;
+import mage.abilities.effects.ContinuousEffectImpl;
 import mage.abilities.effects.common.continuous.LoseCreatureTypeSourceEffect;
 import mage.abilities.effects.common.continuous.MaximumHandSizeControllerEffect;
 import mage.abilities.keyword.IndestructibleAbility;
@@ -12,7 +12,7 @@ import mage.cards.CardImpl;
 import mage.cards.CardSetInfo;
 import mage.constants.*;
 import mage.game.Game;
-import mage.game.events.GameEvent;
+import mage.players.Player;
 
 import java.util.UUID;
 
@@ -41,9 +41,9 @@ public final class KruphixGodOfHorizons extends CardImpl {
                 Integer.MAX_VALUE, Duration.WhileOnBattlefield,
                 MaximumHandSizeControllerEffect.HandSizeModification.SET
         )));
+
         // If unused mana would empty from your mana pool, that mana becomes colorless instead.
         this.addAbility(new SimpleStaticAbility(new KruphixGodOfHorizonsEffect()));
-
     }
 
     private KruphixGodOfHorizons(final KruphixGodOfHorizons card) {
@@ -56,11 +56,11 @@ public final class KruphixGodOfHorizons extends CardImpl {
     }
 }
 
-class KruphixGodOfHorizonsEffect extends ReplacementEffectImpl {
+class KruphixGodOfHorizonsEffect extends ContinuousEffectImpl {
 
     KruphixGodOfHorizonsEffect() {
-        super(Duration.WhileOnBattlefield, Outcome.Benefit);
+        super(Duration.WhileOnBattlefield, Layer.RulesEffects, SubLayer.NA, Outcome.Benefit);
-        staticText = "If you would lose unspent mana, that mana becomes colorless instead.";
+        staticText = "if you would lose unspent mana, that mana becomes colorless instead";
     }
 
     private KruphixGodOfHorizonsEffect(final KruphixGodOfHorizonsEffect effect) {
@@ -74,21 +74,10 @@ class KruphixGodOfHorizonsEffect extends ReplacementEffectImpl {
 
     @Override
     public boolean apply(Game game, Ability source) {
-        return false;
+        Player player = game.getPlayer(source.getControllerId());
+        if (player != null) {
+            player.getManaPool().setManaBecomesColorless(true);
         }
-
-    @Override
-    public boolean replaceEvent(GameEvent event, Ability source, Game game) {
         return true;
     }
-
-    @Override
-    public boolean checksEventType(GameEvent event, Game game) {
-        return event.getType() == GameEvent.EventType.EMPTY_MANA_POOL;
-    }
-
-    @Override
-    public boolean applies(GameEvent event, Ability source, Game game) {
-        return event.getPlayerId().equals(source.getControllerId());
-    }
 }

Mage.Tests/src/test/java/org/mage/test/cards/single/jou/KruphixGodOfHorizonsTest.java

@@ -0,0 +1,62 @@
+package org.mage.test.cards.single.jou;
+
+import mage.constants.ManaType;
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author TheElk801
+ */
+public class KruphixGodOfHorizonsTest extends CardTestPlayerBase {
+
+    private static final String kruphix = "Kruphix, God of Horizons";
+    private static final String sliver = "Metallic Sliver";
+    private static final String repeal = "Mystic Repeal";
+
+    @Test
+    public void testKruphixNormal() {
+        addCard(Zone.BATTLEFIELD, playerA, "Forest", 3);
+        addCard(Zone.BATTLEFIELD, playerA, kruphix);
+
+        activateManaAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+        activateManaAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+        activateManaAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+
+        setStrictChooseMode(true);
+        setStopAt(3, PhaseStep.END_TURN);
+        execute();
+        assertAllCommandsUsed();
+
+        assertManaPool(playerA, ManaType.COLORLESS, 3);
+        assertManaPool(playerA, ManaType.GREEN, 0);
+        assertPermanentCount(playerA, kruphix, 1);
+    }
+
+    @Test
+    public void testKruphixRemoved() {
+        addCard(Zone.BATTLEFIELD, playerA, "Forest", 3);
+        addCard(Zone.BATTLEFIELD, playerA, kruphix);
+        addCard(Zone.HAND, playerA, sliver);
+        addCard(Zone.HAND, playerA, repeal);
+
+        activateManaAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+        activateManaAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+        activateManaAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{T}");
+
+        castSpell(3, PhaseStep.PRECOMBAT_MAIN, playerA, sliver);
+        castSpell(3, PhaseStep.PRECOMBAT_MAIN, playerA, repeal, kruphix);
+
+        setStrictChooseMode(true);
+        setStopAt(3, PhaseStep.END_TURN);
+        execute();
+        assertAllCommandsUsed();
+
+        assertManaPool(playerA, ManaType.COLORLESS, 0);
+        assertManaPool(playerA, ManaType.GREEN, 0);
+        assertPermanentCount(playerA, sliver, 1);
+        assertPermanentCount(playerA, kruphix, 0);
+        assertTappedCount("Forest", true, 1);
+    }
+}

Mage/src/main/java/mage/ConditionalMana.java

@@ -17,7 +17,7 @@ import java.util.UUID;
 /**
  * @author nantuko
  */
-public class ConditionalMana extends Mana implements Serializable {
+public class ConditionalMana extends Mana implements Serializable, Emptiable {
 
     /**
      * Conditions that should be met (all or any depending on comparison scope)

Mage/src/main/java/mage/Emptiable.java

@@ -0,0 +1,15 @@
+package mage;
+
+import mage.constants.ManaType;
+
+/**
+ * @author TheElk801
+ */
+public interface Emptiable {
+
+    public void add(ManaType manaType, int amount);
+
+    public void clear(ManaType manaType);
+
+    public int get(final ManaType manaType);
+}

Mage/src/main/java/mage/players/ManaPool.java

@@ -1,6 +1,7 @@
 package mage.players;
 
 import mage.ConditionalMana;
+import mage.Emptiable;
 import mage.MageObject;
 import mage.Mana;
 import mage.abilities.Ability;
@@ -37,6 +38,7 @@ public class ManaPool implements Serializable {
     private final List<ManaPoolItem> poolBookmark = new ArrayList<>(); // mana pool bookmark for rollback purposes
 
     private final Set<ManaType> doNotEmptyManaTypes = new HashSet<>();
+    private boolean manaBecomesColorless = false;
 
     private static final class ConditionalManaInfo {
         private final ManaType manaType;
@@ -73,6 +75,7 @@ public class ManaPool implements Serializable {
         }
         this.doNotEmptyManaTypes.addAll(pool.doNotEmptyManaTypes);
         this.lastPaymentWasSnow = pool.lastPaymentWasSnow;
+        this.manaBecomesColorless = pool.manaBecomesColorless;
     }
 
     public int getRed() {
@@ -229,12 +232,21 @@ public class ManaPool implements Serializable {
 
     public void clearEmptyManaPoolRules() {
         doNotEmptyManaTypes.clear();
+        this.manaBecomesColorless = false;
     }
 
     public void addDoNotEmptyManaType(ManaType manaType) {
         doNotEmptyManaTypes.add(manaType);
     }
 
+    public void setManaBecomesColorless(boolean manaBecomesColorless) {
+        this.manaBecomesColorless = manaBecomesColorless;
+    }
+
+    public boolean isManaBecomesColorless() {
+        return manaBecomesColorless;
+    }
+
     public void init() {
         manaItems.clear();
     }
@@ -246,35 +258,15 @@ public class ManaPool implements Serializable {
             ManaPoolItem item = it.next();
             ConditionalMana conditionalItem = item.getConditionalMana();
             for (ManaType manaType : ManaType.values()) {
-                if (!doNotEmptyManaTypes.contains(manaType)) {
+                if (doNotEmptyManaTypes.contains(manaType)) {
+                    continue;
+                }
                 if (item.get(manaType) > 0) {
-                        if (item.getDuration() != Duration.EndOfTurn
+                    total += emptyItem(item, item, game, manaType);
-                                || game.getPhase().getType() == TurnPhase.END) {
-                            if (game.replaceEvent(new GameEvent(GameEvent.EventType.EMPTY_MANA_POOL, playerId, null, playerId))) {
-                                int amount = item.get(manaType);
-                                item.clear(manaType);
-                                item.add(ManaType.COLORLESS, amount);
-                            } else {
-                                total += item.get(manaType);
-                                item.clear(manaType);
-                            }
-                        }
-                    }
-                    if (conditionalItem != null) {
-                        if (conditionalItem.get(manaType) > 0) {
-                            if (item.getDuration() != Duration.EndOfTurn
-                                    || game.getPhase().getType() == TurnPhase.END) {
-                                if (game.replaceEvent(new GameEvent(GameEvent.EventType.EMPTY_MANA_POOL, playerId, null, playerId))) {
-                                    int amount = conditionalItem.get(manaType);
-                                    conditionalItem.clear(manaType);
-                                    conditionalItem.add(ManaType.COLORLESS, amount);
-                                } else {
-                                    total += conditionalItem.get(manaType);
-                                    conditionalItem.clear(manaType);
-                                }
-                            }
-                        }
                 }
+                if (conditionalItem != null
+                        && conditionalItem.get(manaType) > 0) {
+                    total += emptyItem(item, conditionalItem, game, manaType);
                 }
             }
             if (item.count() == 0) {
@@ -284,6 +276,22 @@ public class ManaPool implements Serializable {
         return total;
     }
 
+    private int emptyItem(ManaPoolItem item, Emptiable toEmpty, Game game, ManaType manaType) {
+        if (item.getDuration() == Duration.EndOfTurn
+                && game.getPhase().getType() != TurnPhase.END) {
+            return 0;
+        }
+        if (!manaBecomesColorless) {
+            int amount = toEmpty.get(manaType);
+            toEmpty.clear(manaType);
+            return amount;
+        }
+        int amount = toEmpty.get(manaType);
+        toEmpty.clear(manaType);
+        toEmpty.add(ManaType.COLORLESS, amount);
+        return 0;
+    }
+
     public Mana getMana() {
         Mana m = new Mana();
         for (ManaPoolItem item : manaItems) {

Mage/src/main/java/mage/players/ManaPoolItem.java

@@ -5,6 +5,7 @@ import java.util.UUID;
 import mage.ConditionalMana;
 import mage.MageObject;
 import mage.Mana;
+import mage.Emptiable;
 import mage.constants.Duration;
 import mage.constants.ManaType;
 
@@ -12,7 +13,7 @@ import mage.constants.ManaType;
  *
  * @author BetaSteward_at_googlemail.com
  */
-public class ManaPoolItem implements Serializable {
+public class ManaPoolItem implements Serializable, Emptiable {
 
     private int red = 0;
     private int green = 0;