* Fixed that the becomes land effects of Gaea's Liege and Graceful Antelope did not end when the source left the battlefield.

Mage.Sets/src/mage/cards/g/GaeasLiege.java

@@ -1,6 +1,6 @@
-
 package mage.cards.g;
 
+import java.util.UUID;
 import mage.MageInt;
 import mage.abilities.Ability;
 import mage.abilities.common.SimpleActivatedAbility;
@@ -28,8 +28,6 @@ import mage.game.combat.CombatGroup;
 import mage.game.permanent.Permanent;
 import mage.target.common.TargetLandPermanent;
 
-import java.util.UUID;
-
 /**
  *
  * @author anonymous
@@ -55,8 +53,8 @@ public final class GaeasLiege extends CardImpl {
                 new SetPowerToughnessSourceEffect(new DefendersForestCount(), Duration.EndOfCombat),
                 new InvertCondition(SourceAttackingCondition.instance),
                 "As long as {this} isn't attacking, its power and toughness are each equal to the number of Forests you control. As long as {this} is attacking, its power and toughness are each equal to the number of Forests defending player controls.")));
-        // {tap}: Target land becomes a Forest until Gaea's Liege leaves the battlefield.
+        // {T}: Target land becomes a Forest until Gaea's Liege leaves the battlefield.
-        Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new BecomesBasicLandTargetEffect(Duration.WhileOnBattlefield, SubType.FOREST), new TapSourceCost());
+        Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new BecomesBasicLandTargetEffect(Duration.UntilSourceLeavesBattlefield, SubType.FOREST), new TapSourceCost());
         ability.addTarget(new TargetLandPermanent());
         this.addAbility(ability);
     }

Mage.Sets/src/mage/cards/g/GracefulAntelope.java

@@ -1,6 +1,6 @@
-
 package mage.cards.g;
 
+import java.util.UUID;
 import mage.MageInt;
 import mage.abilities.Ability;
 import mage.abilities.common.DealsCombatDamageToAPlayerTriggeredAbility;
@@ -11,11 +11,8 @@ import mage.cards.CardSetInfo;
 import mage.constants.CardType;
 import mage.constants.Duration;
 import mage.constants.SubType;
-import mage.target.Target;
 import mage.target.common.TargetLandPermanent;
 
-import java.util.UUID;
-
 /**
  *
  * @author cbt33, Loki (Contaminated Ground), Plopman (Larceny)
@@ -32,9 +29,8 @@ public final class GracefulAntelope extends CardImpl {
         // Plainswalk
         this.addAbility(new PlainswalkAbility());
         // Whenever Graceful Antelope deals combat damage to a player, you may have target land become a Plains until Graceful Antelope leaves the battlefield.
-        Ability ability = new DealsCombatDamageToAPlayerTriggeredAbility(new BecomesBasicLandTargetEffect(Duration.WhileOnBattlefield, SubType.PLAINS), true);
+        Ability ability = new DealsCombatDamageToAPlayerTriggeredAbility(new BecomesBasicLandTargetEffect(Duration.UntilSourceLeavesBattlefield, SubType.PLAINS), true);
-        Target target = new TargetLandPermanent();
+        ability.addTarget(new TargetLandPermanent());
-        ability.addTarget(target);
         this.addAbility(ability);
     }
 

Mage/src/main/java/mage/abilities/effects/ContinuousEffectsList.java

@@ -1,14 +1,13 @@
-
 package mage.abilities.effects;
 
+import java.util.*;
 import mage.abilities.Ability;
 import mage.abilities.MageSingleton;
 import mage.constants.Duration;
+import mage.constants.Zone;
 import mage.game.Game;
 import org.apache.log4j.Logger;
 
-import java.util.*;
-
 /**
  * @param <T>
  * @author BetaSteward_at_googlemail.com
@@ -106,6 +105,11 @@ public class ContinuousEffectsList<T extends ContinuousEffect> extends ArrayList
                         if (effect.isInactive(ability, game)) {
                             it.remove();
                         }
+                        break;
+                    case UntilSourceLeavesBattlefield:
+                        if (Zone.BATTLEFIELD != game.getState().getZone(ability.getSourceId())) {
+                            it.remove();
+                        }
                 }
             }
         }

Mage/src/main/java/mage/constants/Duration.java

@@ -12,6 +12,7 @@ public enum Duration {
     WhileInGraveyard("", false),
     EndOfTurn("until end of turn", true),
     UntilYourNextTurn("until your next turn", true),
+    UntilSourceLeavesBattlefield("until {source} leaves the battlefield", true), // supported for continuous layered effects
     EndOfCombat("until end of combat", true),
     EndOfStep("until end of phase step", true),
     Custom("", true);