fix #12022 (Shipwreck Sentry)

Mage.Sets/src/mage/cards/s/ShipwreckSentry.java

@@ -77,7 +77,7 @@ class ShipwreckSentryWatcher extends Watcher {
         }
         EntersTheBattlefieldEvent eEvent = (EntersTheBattlefieldEvent) event;
         if (eEvent.getTarget() != null && eEvent.getTarget().isArtifact(game)) {
-            playerSet.add(eEvent.getTarget().getId());
+            playerSet.add(eEvent.getTarget().getControllerId());
         }
     }
 

Mage.Tests/src/test/java/org/mage/test/cards/single/lci/ShipwreckSentryTest.java

@@ -0,0 +1,61 @@
+package org.mage.test.cards.single.lci;
+
+import mage.constants.PhaseStep;
+import mage.constants.Zone;
+import org.junit.Assert;
+import org.junit.Test;
+import org.mage.test.serverside.base.CardTestPlayerBase;
+
+/**
+ * @author xenohedron
+ */
+public class ShipwreckSentryTest extends CardTestPlayerBase {
+
+    /**
+     Shipwreck Sentry {1}{U}
+     Creature — Human Pirate
+     Defender
+     As long as an artifact entered the battlefield under your control this turn, Shipwreck Sentry can attack as though it didn’t have defender.
+     */
+    private static final String sentry = "Shipwreck Sentry";
+
+    // {0} Artifact
+    private static final String relic = "Darksteel Relic";
+
+    @Test
+    public void testCantAttack() {
+        addCard(Zone.BATTLEFIELD, playerA, sentry);
+        addCard(Zone.HAND, playerA, relic);
+
+        attack(1, playerA, sentry, playerB);
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.POSTCOMBAT_MAIN);
+        try {
+            execute();
+        } catch (AssertionError e) {
+            Assert.assertTrue("No artifact entered",
+                    e.getMessage().contains("Can't find available command - attack:Shipwreck Sentry$defendingPlayer=PlayerB"));
+        }
+
+    }
+
+    @Test
+    public void testCanAttack() {
+        addCard(Zone.BATTLEFIELD, playerA, sentry);
+        addCard(Zone.HAND, playerA, relic);
+
+        castSpell(1, PhaseStep.PRECOMBAT_MAIN, playerA, relic);
+        attack(1, playerA, sentry, playerB);
+
+        setStrictChooseMode(true);
+        setStopAt(1, PhaseStep.POSTCOMBAT_MAIN);
+        execute();
+
+        assertPermanentCount(playerA, relic, 1);
+        assertTappedCount(sentry, true, 1);
+        assertLife(playerB, 17);
+
+    }
+
+}

Mage/src/main/java/mage/watchers/common/PermanentsEnteredBattlefieldWatcher.java

@@ -50,7 +50,7 @@ public class PermanentsEnteredBattlefieldWatcher extends Watcher {
     }
 
     public List<Permanent> getThisTurnEnteringPermanents(UUID playerId) {
-        return enteringBattlefield.get(playerId);
+        return enteringBattlefield.getOrDefault(playerId, Collections.emptyList());
     }
 
     public boolean anotherCreatureEnteredBattlefieldUnderPlayersControlLastTurn(Permanent sourcePermanent, Game game) {