* Cumulative Upkeep - Fixed that a permanent with CU was wrongly sacrificed if the control of the permanent has changed since CU begin of upkeep trigger was put on the stack. Added tests for CU.

Mage.Tests/src/test/java/org/mage/test/cards/abilities/keywords/CumulativeUpkeepTest.java

@@ -0,0 +1,110 @@
+
+package org.mage.test.cards.abilities.keywords;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import mage.counters.CounterType;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ *
+ * @author LevelX2
+ */
+
+public class CumulativeUpkeepTest extends CardTestPlayerBase {
+
+    @Test
+    public void basicTest() {
+        setStrictChooseMode(true);
+        
+        addCard(Zone.BATTLEFIELD, playerA, "Swamp", 3);
+        // Flying; fear
+        // Cumulative upkeep {B}
+        addCard(Zone.HAND, playerA, "Phobian Phantasm"); // Creature {1}{B}{B} 3/3
+
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Phobian Phantasm");
+
+        // Phobian Phantasm - CumulativeUpkeepAbility: Cumulative upkeep {B}
+        setChoice(playerA, "Yes"); // Pay {B}?                        
+        attack(3, playerA, "Phobian Phantasm");
+        checkPermanentCounters("Age counters", 3, PhaseStep.PRECOMBAT_MAIN, playerA, "Phobian Phantasm", CounterType.AGE, 1);
+        
+        setChoice(playerA, "Yes"); // Pay {B}{B}?
+        attack(5, playerA, "Phobian Phantasm");
+        checkPermanentCounters("Age counters", 5, PhaseStep.PRECOMBAT_MAIN, playerA, "Phobian Phantasm", CounterType.AGE, 2);
+        
+        setChoice(playerA, "No"); // Pay {B}{B}{B}?
+        
+        setStopAt(7, PhaseStep.BEGIN_COMBAT);
+        execute();
+
+        assertAllCommandsUsed();
+        
+        assertGraveyardCount(playerA, "Phobian Phantasm", 1);
+        
+        assertLife(playerA, 20);
+        assertLife(playerB, 14);
+    }
+
+
+    /**
+     I changed control of a Illusions of Grandeur to an AI after cumulative upkeep had triggered but before it resolved.
+     I chose not to pay the upkeep cost and then either the AI sacrificed it or I sacrificed it, neither of which should happen.
+     I can't sacrifice it because it's not under my control. The AI can't sacrifice it because they are not instructed to do so.
+
+     Here is the reminder text for cumulative upkeep:
+     At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.
+     */
+    @Test
+    public void controlChangeTest() {
+        setStrictChooseMode(true);
+        
+        // Whenever Kor Celebrant or another creature enters the battlefield under your control, you gain 1 life.
+        addCard(Zone.HAND, playerB, "Kor Celebrant", 1); // Creature {2}{W}
+        addCard(Zone.BATTLEFIELD, playerB, "Plains", 3);
+        
+        addCard(Zone.BATTLEFIELD, playerA, "Island", 6);
+        // Cumulative upkeep {2}
+        // When Illusions of Grandeur enters the battlefield, you gain 20 life.
+        // When Illusions of Grandeur leaves the battlefield, you lose 20 life.
+        addCard(Zone.HAND, playerA, "Illusions of Grandeur"); // Enchantment {3}{U}
+        
+        // At the beginning of your upkeep, you may exchange control of target nonland permanent you control and target nonland permanent an opponent controls with an equal or lesser converted mana cost.        
+        addCard(Zone.HAND, playerA, "Puca's Mischief"); // Enchantment {3}{U}
+
+        
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Illusions of Grandeur");
+             
+        castSpell(2, PhaseStep.PRECOMBAT_MAIN, playerB, "Kor Celebrant");
+        
+        // Illusions of Grandeur - CumulativeUpkeepAbility: Cumulative upkeep {2}
+        setChoice(playerA, "Yes"); // Pay {2}?                        
+        
+        castSpell(3, PhaseStep.PRECOMBAT_MAIN, playerA, "Puca's Mischief");
+        
+        setChoice(playerA, "Cumulative upkeep"); // Triggered list (total 2) which trigger goes first on the stack
+        addTarget(playerA, "Illusions of Grandeur"); // Own target permanent of Puca's Mischief
+        addTarget(playerA, "Kor Celebrant"); // Opponent's target permanent of Puca's Mischief
+        
+        setChoice(playerA, "Yes"); // At the beginning of your upkeep, you may exchange control of target nonland permanent you control and target nonland permanent an opponent controls with an equal or lesser converted mana cost.
+        setChoice(playerA, "No"); // Pay {2}{2}?
+        
+        checkPermanentCounters("Age counters", 5, PhaseStep.PRECOMBAT_MAIN, playerB, "Illusions of Grandeur", CounterType.AGE, 2);
+        
+        setStopAt(5, PhaseStep.BEGIN_COMBAT);
+        execute();
+
+        assertAllCommandsUsed();
+        
+        assertLife(playerA, 40);
+        assertLife(playerB, 21);  
+        
+        assertPermanentCount(playerA, "Kor Celebrant", 1);
+        assertPermanentCount(playerB, "Illusions of Grandeur", 1);
+        
+
+    }
+
+        
+}

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

@@ -89,7 +89,9 @@ class CumulativeUpkeepEffect extends OneShotEffect {
                     }
                 }
                 game.fireEvent(new GameEvent(GameEvent.EventType.DIDNT_PAY_CUMULATIVE_UPKEEP, permanent.getId(), source, player.getId(), ageCounter, false));
-                permanent.sacrifice(source, game);
+                if (source.getControllerId().equals(permanent.getControllerId())) { // Permanent can only be sacrificed if you still control it
+                    permanent.sacrifice(source, game);
+                }
                 return true;
             } else {
                 CostsImpl<Cost> totalCost = new CostsImpl<>();