Fixed NPE on portal use when there is no Nether world

https://github.com/BentoBoxWorld/bentobox/issues/365

src/main/java/world/bentobox/bentobox/listeners/NetherPortals.java

@@ -110,6 +110,7 @@ public class NetherPortals implements Listener {
             return;
         }
         World overWorld = Util.getWorld(e.getFrom().getWorld());
+
         // If entering a portal in the end, teleport home if you have one, else do nothing
         if (e.getFrom().getWorld().getEnvironment().equals(Environment.THE_END)) {
             if (plugin.getIslands().hasIsland(overWorld, e.getPlayer().getUniqueId())) {
@@ -194,7 +195,8 @@ public class NetherPortals implements Listener {
             return false;
         }
         World fromWorld = e.getFrom().getWorld();
-        if (!e.getCause().equals(TeleportCause.NETHER_PORTAL) || !plugin.getIWM().inWorld(e.getFrom())) {
+        if (!e.getCause().equals(TeleportCause.NETHER_PORTAL) || !plugin.getIWM().inWorld(e.getFrom())
+                || !plugin.getIWM().isNetherGenerate(fromWorld)) {
             // Do nothing special
             return false;
         }

src/main/java/world/bentobox/bentobox/managers/IslandsManager.java

@@ -163,7 +163,7 @@ public class IslandsManager {
      * @return true if safe, otherwise false
      */
     public boolean isSafeLocation(Location l) {
-        if (l == null) {
+        if (l == null || l.getWorld() == null) {
             return false;
         }
         Block ground = l.getBlock().getRelative(BlockFace.DOWN);

src/test/java/world/bentobox/bentobox/listeners/NetherPortalsTest.java

@@ -88,8 +88,10 @@ public class NetherPortalsTest {
         end = mock(World.class);
         when(end.getEnvironment()).thenReturn(Environment.THE_END);
         when(iwm.getEndWorld(Mockito.any())).thenReturn(end);
+        when(iwm.isEndGenerate(Mockito.any())).thenReturn(true);
         when(iwm.getIslandWorld(Mockito.any())).thenReturn(world);
         when(iwm.getNetherWorld(Mockito.any())).thenReturn(nether);
+        when(iwm.isNetherGenerate(Mockito.any())).thenReturn(true);
         when(iwm.inWorld(any(World.class))).thenReturn(true);
         when(iwm.inWorld(any(Location.class))).thenReturn(true);
         when(iwm.getNetherSpawnRadius(Mockito.any())).thenReturn(100);
@@ -267,13 +269,47 @@ public class NetherPortalsTest {
      */
     @Test
     public void testOnEndIslandPortalNotEnd() {
+        Location from = mock(Location.class);
+        // Teleport from world to nether
+        when(from.getWorld()).thenReturn(world);
+        when(from.toVector()).thenReturn(new Vector(1,2,3));
         NetherPortals np = new NetherPortals(plugin);
         // Wrong cause
-        PlayerPortalEvent e = new PlayerPortalEvent(null, null, null, null, TeleportCause.CHORUS_FRUIT);
+        PlayerPortalEvent e = new PlayerPortalEvent(null, from, null, null, TeleportCause.CHORUS_FRUIT);
         np.onEndIslandPortal(e);
         assertFalse(e.isCancelled());
     }
 
+    /**
+     * Test method for {@link world.bentobox.bentobox.listeners.NetherPortals#onEndIslandPortal(org.bukkit.event.player.PlayerPortalEvent)}.
+     */
+    @Test
+    public void testOnEndIslandPortalNoEndWorldGenerated() {
+        Location from = mock(Location.class);
+        // Teleport from world to nether
+        when(from.getWorld()).thenReturn(world);
+        when(from.toVector()).thenReturn(new Vector(1,2,3));
+        // No end world
+        when(iwm.isEndGenerate(Mockito.any())).thenReturn(false);
+        NetherPortals np = new NetherPortals(plugin);
+        PlayerPortalEvent e = new PlayerPortalEvent(null, from, null, null, TeleportCause.END_PORTAL);
+        np.onEndIslandPortal(e);
+        assertFalse(e.isCancelled());
+    }
+
+    /**
+     * Test method for {@link world.bentobox.bentobox.listeners.NetherPortals#onEndIslandPortal(org.bukkit.event.player.PlayerPortalEvent)}.
+     */
+    @Test
+    public void testOnNetherIslandPortalNoNetherWorldGenerated() {
+        // No nether world
+        when(iwm.isNetherGenerate(Mockito.any())).thenReturn(false);
+        NetherPortals np = new NetherPortals(plugin);
+        PlayerPortalEvent e = new PlayerPortalEvent(null, null, null, null, TeleportCause.NETHER_PORTAL);
+        np.onNetherPortal(e);
+        assertFalse(e.isCancelled());
+    }
+
     /**
      * Test method for {@link world.bentobox.bentobox.listeners.NetherPortals#onEndIslandPortal(org.bukkit.event.player.PlayerPortalEvent)}.
      */

src/test/java/world/bentobox/bentobox/managers/IslandsManagerTest.java

@@ -136,6 +136,7 @@ public class IslandsManagerTest {
         ground = mock(Block.class);
         space2 = mock(Block.class);
         when(location.getBlock()).thenReturn(space1);
+        when(location.getWorld()).thenReturn(world);
         when(space1.getRelative(BlockFace.DOWN)).thenReturn(ground);
         when(space1.getRelative(BlockFace.UP)).thenReturn(space2);
         // A safe spot
@@ -194,6 +195,16 @@ public class IslandsManagerTest {
         assertFalse(manager.isSafeLocation(null));
     }
 
+    /**
+     * Test method for {@link world.bentobox.bentobox.managers.IslandsManager#isSafeLocation(org.bukkit.Location)}.
+     */
+    @Test
+    public void testIsSafeLocationNullWorld() {
+        when(location.getWorld()).thenReturn(null);
+        IslandsManager manager = new IslandsManager(plugin);
+        assertFalse(manager.isSafeLocation(location));
+    }
+
     /**
      * Test method for {@link world.bentobox.bentobox.managers.IslandsManager#isSafeLocation(org.bukkit.Location)}.
      */