Teleport async on Paper.

worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/BukkitPlayer.java

@@ -181,9 +181,16 @@ public void resetFallDistance() {
     }
 
     @Override
-    public void teleport(Location location, String message) {
+    public void teleport(Location location, String successMessage, String failMessage) {
         PaperLib.teleportAsync(getPlayer(), BukkitAdapter.adapt(location))
-                .thenApply(success -> { if (success) print(message); return success; });
+                .thenApply(success -> {
+                    if (success) {
+                        print(successMessage);
+                    } else {
+                        printError(failMessage);
+                    }
+                    return success;
+                });
     }
 
     @Override

worldguard-bukkit/src/main/java/com/sk89q/worldguard/bukkit/listener/WorldGuardPlayerListener.java

@@ -413,9 +413,8 @@ public void onPlayerTeleport(PlayerTeleportEvent event) {
                     }
                 }
             }
-            if (null != WorldGuard.getInstance().getPlatform().getSessionManager().get(localPlayer).testMoveTo(localPlayer,
-                    BukkitAdapter.adapt(event.getTo()),
-                    MoveType.TELEPORT)) {
+            if (null != WorldGuard.getInstance().getPlatform().getSessionManager().get(localPlayer)
+                    .testMoveTo(localPlayer, BukkitAdapter.adapt(event.getTo()), MoveType.TELEPORT)) {
                 event.setCancelled(true);
                 return;
             }

worldguard-core/src/main/java/com/sk89q/worldguard/LocalPlayer.java

@@ -212,4 +212,12 @@ default Association getAssociation(List<ProtectedRegion> regions) {
      * Clears fall distance.
      */
     void resetFallDistance();
+
+    /**
+     * Teleport the player, potentially async, displaying the message on a success.
+     *  @param location location to teleport to
+     * @param successMessage message to display on success
+     * @param failMessage message to display on failure
+     */
+    void teleport(Location location, String successMessage, String failMessage);
 }

worldguard-core/src/main/java/com/sk89q/worldguard/commands/region/RegionCommands.java

@@ -1091,8 +1091,9 @@ public void teleport(CommandContext args, Actor sender) throws CommandException
             }
         }
 
-        player.setLocation(teleportLocation);
-        sender.print("Teleported you to the region '" + existing.getId() + "'.");
+        player.teleport(teleportLocation,
+                "Teleported you to the region '" + existing.getId() + "'.",
+                "Unable to teleport to region '" + existing.getId() + "'.");
     }
 
     private static class FlagListBuilder implements Callable<Component> {

worldguard-core/src/test/java/com/sk89q/worldguard/TestPlayer.java

@@ -183,6 +183,11 @@ public void resetFallDistance() {
 
     }
 
+    @Override
+    public void teleport(Location location, String successMessage, String failMessage) {
+
+    }
+
     @Override
     public void printRaw(String msg) {
         System.out.println("-> TestPlayer{" + this.name + "}: " + msg);

worldguard-core/src/test/java/com/sk89q/worldguard/protection/ApplicableRegionSetTest.java

@@ -638,4 +638,11 @@ public void testGlobalRegionCommandBlacklistWithRegionWhitelist() {
         assertThat(test.apply("/deny"), is(false));
     }
 
+    @Test
+    public void testRegionSetReturnsNullForUnsetState() {
+        MockApplicableRegionSet mock = new MockApplicableRegionSet();
+        mock.add(0);
+        mock.add(1);
+        assertNull(mock.getApplicableSet().queryState(null, Flags.INTERACT));
+    }
 }