Tests: added support of zero targets in TestPlayer (empty string in addTarget);

Tests: fixed CopySpellTest;

Mage.Tests/src/test/java/org/mage/test/cards/copy/CopySpellTest.java

@@ -24,9 +24,15 @@ public class CopySpellTest extends CardTestPlayerBase {
         addCard(Zone.BATTLEFIELD, playerB, "Pillarfield Ox", 1);
         addCard(Zone.BATTLEFIELD, playerB, "Island", 1);
 
+        // start chain from A - return pillar to hand
         castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, "Chain of Vapor", "Pillarfield Ox");
-        setChoice(playerB, "Yes");
-        addTarget(playerB, "Silvercoat Lion");
+        //setChoice(playerB, "Yes"); // want to sacrifice
+        addTarget(playerB, "Island"); // select a land to sacrifice
+        setChoice(playerB, "Yes"); // want to copy spell
+        setChoice(playerB, "Yes"); // want to change target
+        addTarget(playerB, "Silvercoat Lion"); // new target after copy
+        // stop the chain on 0 land
+        addTarget(playerB, "");
 
         setStopAt(1, PhaseStep.BEGIN_COMBAT);
         execute();

Mage.Tests/src/test/java/org/mage/test/player/TestPlayer.java

@@ -1160,6 +1160,13 @@ public class TestPlayer implements Player {
                 abilityControllerId = target.getAbilityController();
             }
 
+            // do not select
+            if (targets.get(0).equals("")) {
+                Assert.assertEquals("found empty choice, but target is not support 0 choice", 0, target.getMinNumberOfTargets());
+                targets.remove(0);
+                return true;
+            }
+
             // player
             if (target instanceof TargetPlayer
                     || target instanceof TargetAnyTarget