Prevent playing lands on NDFC backs

It should not be possible to play a land on the back of a nonmodal
(transforming) double-faced card from anywhere.

Author: matoro

Mage.Tests/src/test/java/org/mage/test/cards/conditional/twofaced/TwoFacedLandAllowedTest.java

@@ -0,0 +1,62 @@
+package org.mage.test.cards.conditional.twofaced;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author matoro
+ */
+public class TwoFacedLandAllowedTest extends CardTestPlayerBase {
+
+    /**
+     * Tests that you are not allowed to play a land on the back of a transforming double-faced card.
+     */
+    @Test
+    public void testTransformingNotAllowed() {
+        setStrictChooseMode(true);
+        addCard(Zone.HAND, playerA, "Ojer Taq, Deepest Foundation");
+        checkPlayableAbility("Should not be able to play land", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Play Temple of Civilization", false);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+    }
+
+    /**
+     * Tests that you are still allowed to play a land on the back of a modal double-faced card.
+     */
+    @Test
+    public void testModalAllowed() {
+        setStrictChooseMode(true);
+        addCard(Zone.HAND, playerA, "Sink into Stupor");
+        checkPlayableAbility("Should be able to play land", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Play Soporific Springs", true);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+    }
+
+    /**
+     * Tests that you are still allowed to play a land on the front of a transforming double-faced card.
+     */
+    @Test
+    public void testTransformingFront() {
+        setStrictChooseMode(true);
+        addCard(Zone.HAND, playerA, "Balamb Garden, SeeD Academy");
+        checkPlayableAbility("Should be able to play land", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "Play Balamb Garden, SeeD Academy", true);
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+    }
+
+    /**
+     * Tests that you can still transform a nonmodal double-faced card with a land on the back.
+     */
+    @Test
+    public void testActivateTransformationAllowed() {
+        setStrictChooseMode(true);
+        addCard(Zone.BATTLEFIELD, playerA, "Tarrian's Journal");
+        addCard(Zone.BATTLEFIELD, playerA, "Swamp", 2);
+        activateAbility(1, PhaseStep.PRECOMBAT_MAIN, playerA, "{2}, {T}, Discard your hand: Transform {this}.");
+        setStopAt(1, PhaseStep.END_TURN);
+        execute();
+        checkPermanentCount("Successfully transformed", 1, PhaseStep.PRECOMBAT_MAIN, playerA, "The Tomb of Aclazotz", 1);
+    }
+}

Mage/src/main/java/mage/cards/TransformingDoubleFacedCardHalf.java

@@ -1,6 +1,9 @@
 package mage.cards;
 
 import mage.ObjectColor;
+import mage.abilities.Abilities;
+import mage.abilities.Ability;
+import mage.abilities.PlayLandAbility;
 import mage.abilities.SpellAbility;
 import mage.constants.*;
 import mage.game.Game;
@@ -46,4 +49,16 @@ public TransformingDoubleFacedCardHalf copy() {
     public TransformingDoubleFacedCard getParentCard() {
         return (TransformingDoubleFacedCard) parentCard;
     }
+
+    @Override
+    public Abilities<Ability> getAbilities() {
+        final Abilities<Ability> all = super.getAbilities();
+
+        // lands on the back of transforming double-faced cards should not be playable
+        if (this.isBackSide()) {
+            all.removeIf(ability -> ability instanceof PlayLandAbility);
+        }
+
+        return all;
+    }
 }