* Buyback ability - fixed that it doesn't work after rollbacks (#5835, #5836);

Mage.Tests/src/test/java/org/mage/test/rollback/DemonicCollusionTest.java

@@ -0,0 +1,78 @@
+package org.mage.test.rollback;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author JayDi85
+ */
+public class DemonicCollusionTest extends CardTestPlayerBase {
+
+    // https://github.com/magefree/mage/issues/5835
+
+    // Demonic Collusion {3}{B}{B}
+    // Buyback—Discard two cards. (You may discard two cards in addition to any other costs as you cast this spell.
+    // If you do, put this card into your hand as it resolves.)
+
+    // Search your library for a card and put that card into your hand. Then shuffle your library.
+
+    @Test
+    public void test_BuybackNormal() {
+        addCard(Zone.HAND, playerA, "Demonic Collusion", 1);
+        addCard(Zone.BATTLEFIELD, playerA, "Swamp", 5);
+        addCard(Zone.HAND, playerA, "Forest", 2);
+
+        checkHandCardCount("before", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Demonic Collusion", 1);
+        checkHandCardCount("before", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Forest", 2);
+
+        // cast with buyback
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Demonic Collusion");
+        setChoice(playerA, "Yes"); // use buyback
+        setChoice(playerA, "Forest"); // pay
+        setChoice(playerA, "Forest"); // pay
+        addTarget(playerA, "Mountain"); // return from lib
+
+        checkHandCardCount("after", 1, PhaseStep.BEGIN_COMBAT, playerA, "Demonic Collusion", 1);
+        checkHandCardCount("after", 1, PhaseStep.BEGIN_COMBAT, playerA, "Forest", 0);
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+        assertAllCommandsUsed();
+    }
+
+    @Test
+    public void test_BuybackAfterRollback() {
+        addCard(Zone.HAND, playerA, "Demonic Collusion", 1);
+        addCard(Zone.BATTLEFIELD, playerA, "Swamp", 5);
+        addCard(Zone.HAND, playerA, "Forest", 2);
+
+        // turn 1
+        checkHandCardCount("before roll", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Demonic Collusion", 1);
+        checkHandCardCount("before roll", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Forest", 2);
+
+        // turn 3 - rollback at the end (to the start)
+        rollbackTurns(3, PhaseStep.PRECOMBAT_MAIN, playerA, 0);
+
+        // turn 5 - check
+        checkHandCardCount("after roll", 5, PhaseStep.PRECOMBAT_MAIN, playerA, "Demonic Collusion", 1);
+        checkHandCardCount("after roll", 5, PhaseStep.PRECOMBAT_MAIN, playerA, "Forest", 2);
+
+        // cast with buyback
+        castSpell(5, PhaseStep.PRECOMBAT_MAIN, playerA, "Demonic Collusion");
+        setChoice(playerA, "Yes"); // use buyback
+        setChoice(playerA, "Forest"); // pay
+        setChoice(playerA, "Forest"); // pay
+        addTarget(playerA, "Mountain"); // return from lib
+
+        checkHandCardCount("after buy", 5, PhaseStep.BEGIN_COMBAT, playerA, "Demonic Collusion", 1);
+        checkHandCardCount("after buy", 5, PhaseStep.BEGIN_COMBAT, playerA, "Forest", 0);
+
+        setStrictChooseMode(true);
+        setStopAt(5, PhaseStep.END_TURN);
+        execute();
+        assertAllCommandsUsed();
+    }
+}

Mage/src/main/java/mage/abilities/condition/common/BuybackCondition.java

@@ -1,4 +1,3 @@
-
 package mage.abilities.condition.common;
 
 import mage.abilities.Ability;
@@ -20,7 +19,7 @@ public enum BuybackCondition implements Condition {
         if (card != null) {
             return card.getAbilities().stream()
                     .filter(a -> a instanceof BuybackAbility)
-                    .anyMatch(Ability::isActivated);
+                    .anyMatch(a -> ((BuybackAbility) a).isBuybackActivated(game));
         }
         return false;
     }

Mage/src/main/java/mage/abilities/costs/OptionalAdditionalCostImpl.java

@@ -1,8 +1,6 @@
-
 package mage.abilities.costs;
 
 /**
- *
  * @author LevelX2
  */
 public class OptionalAdditionalCostImpl extends CostsImpl<Cost> implements OptionalAdditionalCost {
@@ -32,9 +30,10 @@ public class OptionalAdditionalCostImpl extends CostsImpl<Cost> implements Optio
         super(cost);
         this.name = cost.name;
         this.reminderText = cost.reminderText;
+        this.delimiter = cost.delimiter;
         this.activated = cost.activated;
         this.activatedCounter = cost.activatedCounter;
-        this.delimiter = cost.delimiter;
+        this.repeatable = cost.repeatable;
     }
 
     @Override
@@ -95,7 +94,6 @@ public class OptionalAdditionalCostImpl extends CostsImpl<Cost> implements Optio
 
     /**
      * If the player intends to pay the cost, the cost will be activated
-     *
      */
     @Override
     public void activate() {
@@ -105,7 +103,6 @@ public class OptionalAdditionalCostImpl extends CostsImpl<Cost> implements Optio
 
     /**
      * Reset the activate and count information
-     *
      */
     @Override
     public void reset() {
@@ -145,6 +142,7 @@ public class OptionalAdditionalCostImpl extends CostsImpl<Cost> implements Optio
 
     /**
      * Returns the number of times the cost was activated
+     *
      * @return
      */
     @Override

Mage/src/main/java/mage/abilities/keyword/BuybackAbility.java

@@ -1,15 +1,9 @@
-
 package mage.abilities.keyword;
 
-import java.util.Iterator;
 import mage.abilities.Ability;
 import mage.abilities.SpellAbility;
 import mage.abilities.StaticAbility;
-import mage.abilities.costs.Cost;
+import mage.abilities.costs.*;
-import mage.abilities.costs.Costs;
-import mage.abilities.costs.OptionalAdditionalCost;
-import mage.abilities.costs.OptionalAdditionalCostImpl;
-import mage.abilities.costs.OptionalAdditionalSourceCosts;
 import mage.abilities.costs.mana.GenericManaCost;
 import mage.abilities.costs.mana.ManaCostsImpl;
 import mage.abilities.effects.ReplacementEffectImpl;
@@ -22,9 +16,11 @@ import mage.game.events.GameEvent;
 import mage.game.events.ZoneChangeEvent;
 import mage.players.Player;
 
+import java.util.Iterator;
+
 /**
  * 702.25. Buyback
- *
+ * <p>
  * 702.25a Buyback appears on some instants and sorceries. It represents two
  * static abilities that function while the spell is on the stack. "Buyback
  * [cost]" means "You may pay an additional [cost] as you cast this spell" and
@@ -57,7 +53,8 @@ public class BuybackAbility extends StaticAbility implements OptionalAdditionalS
 
     public BuybackAbility(final BuybackAbility ability) {
         super(ability);
-        buybackCost = ability.buybackCost;
+        buybackCost = new OptionalAdditionalCostImpl((OptionalAdditionalCostImpl) ability.buybackCost);
+        amountToReduceBy = ability.amountToReduceBy;
     }
 
     @Override
@@ -67,9 +64,7 @@ public class BuybackAbility extends StaticAbility implements OptionalAdditionalS
 
     @Override
     public void addCost(Cost cost) {
-        if (buybackCost != null) {
+        ((OptionalAdditionalCostImpl) buybackCost).add(cost);
-            ((Costs) buybackCost).add(cost);
-        }
     }
 
     public void resetReduceCost() {
@@ -80,7 +75,6 @@ public class BuybackAbility extends StaticAbility implements OptionalAdditionalS
     public int reduceCost(int genericManaToReduce) {
         int amountToReduce = genericManaToReduce;
         boolean foundCostToReduce = false;
-        if (buybackCost != null) {
         for (Object cost : ((Costs) buybackCost)) {
             if (cost instanceof ManaCostsImpl) {
                 for (Object c : (ManaCostsImpl) cost) {
@@ -97,7 +91,7 @@ public class BuybackAbility extends StaticAbility implements OptionalAdditionalS
                 }
             }
         }
-        }
+
         if (foundCostToReduce) {
             return amountToReduce;
         }
@@ -106,29 +100,39 @@ public class BuybackAbility extends StaticAbility implements OptionalAdditionalS
 
     @Override
     public boolean isActivated() {
-        if (buybackCost != null) {
         return buybackCost.isActivated();
     }
+
+    private void resetBuyback(Game game) {
+        activateBuyback(game, false);
         resetReduceCost();
-        return false;
+        buybackCost.reset();
     }
 
-    public void resetBuyback() {
+    private void activateBuyback(Game game, Boolean isActivated) {
-        if (buybackCost != null) {
+        // xmage uses copies, all statuses must be saved to game state, not abilities
+        game.getState().setValue(this.getSourceId().toString() + "_activatedBuyback", isActivated);
+
+        // for extra info in cast message
+        if (isActivated) {
+            buybackCost.activate();
+        } else {
             buybackCost.reset();
-            resetReduceCost();
         }
     }
 
+    public boolean isBuybackActivated(Game game) {
+        return (Boolean) game.getState().getValue(this.getSourceId().toString() + "_activatedBuyback");
+    }
+
     @Override
     public void addOptionalAdditionalCosts(Ability ability, Game game) {
         if (ability instanceof SpellAbility) {
             Player player = game.getPlayer(ability.getControllerId());
             if (player != null) {
-                this.resetBuyback();
+                this.resetBuyback(game);
-                if (buybackCost != null) {
                 if (player.chooseUse(Outcome.Benefit, "Pay " + buybackCost.getText(false) + " ?", ability, game)) {
-                        buybackCost.activate();
+                    activateBuyback(game, true);
                     for (Iterator it = ((Costs) buybackCost).iterator(); it.hasNext(); ) {
                         Cost cost = (Cost) it.next();
                         if (cost instanceof ManaCostsImpl) {
@@ -141,33 +145,15 @@ public class BuybackAbility extends StaticAbility implements OptionalAdditionalS
             }
         }
     }
-    }
 
     @Override
     public String getRule() {
-        StringBuilder sb = new StringBuilder();
+        return buybackCost.getText(false) + ' ' + buybackCost.getReminderText();
-        if (buybackCost != null) {
-            sb.append(buybackCost.getText(false));
-            sb.append(' ').append(buybackCost.getReminderText());
-        }
-        return sb.toString();
     }
 
     @Override
     public String getCastMessageSuffix() {
-        if (buybackCost != null) {
         return buybackCost.getCastSuffixMessage(0);
-        } else {
-            return "";
-        }
-    }
-
-    public String getReminderText() {
-        if (buybackCost != null) {
-            return buybackCost.getReminderText();
-        } else {
-            return "";
-        }
     }
 }
 
@@ -196,10 +182,9 @@ class BuybackEffect extends ReplacementEffectImpl {
     public boolean applies(GameEvent event, Ability source, Game game) {
         if (event.getTargetId().equals(source.getSourceId())) {
             ZoneChangeEvent zEvent = (ZoneChangeEvent) event;
-            if (zEvent.getFromZone() == Zone.STACK && zEvent.getToZone() == Zone.GRAVEYARD
+            // if spell fizzled, the sourceId is null
-                    && source.getSourceId().equals(event.getSourceId())) { // if spell fizzled, the sourceId is null
+            return zEvent.getFromZone() == Zone.STACK && zEvent.getToZone() == Zone.GRAVEYARD
-                return true;
+                    && source.getSourceId().equals(event.getSourceId());
-            }
         }
         return false;
     }
@@ -213,7 +198,7 @@ class BuybackEffect extends ReplacementEffectImpl {
     public boolean replaceEvent(GameEvent event, Ability source, Game game) {
         Card card = game.getCard(source.getSourceId());
         if (card != null && source instanceof BuybackAbility) {
-            if (((BuybackAbility) source).isActivated()) {
+            if (((BuybackAbility) source).isBuybackActivated(game)) {
                 return card.moveToZone(Zone.HAND, source.getSourceId(), game, true, event.getAppliedEffects());
             }
         }