Recommend paper just like FAWE. I want to be like the cool kids.

Oh, and fix an issue with `/plot music`. Still broken. Just not
the same kind of broken.

Bukkit/src/main/java/com/github/intellectualsites/plotsquared/bukkit/BukkitMain.java

@@ -158,6 +158,15 @@ public final class BukkitMain extends JavaPlugin implements Listener, IPlotMain
 
         PlotPlayer.registerConverter(Player.class, BukkitUtil::getPlayer);
 
+        if (Bukkit.getVersion().contains("git-Spigot")) {
+            // Uses System.out.println because the logger isn't initialized yet
+            System.out.println("[P2] ====== USE PAPER ======");
+            System.out.println("[P2] DOWNLOAD: https://papermc.io/downloads");
+            System.out.println("[P2] GUIDE: https://www.spigotmc.org/threads/21726/");
+            System.out.println("[P2] - This is only a recommendation");
+            System.out.println("[P2] ==============================");
+        }
+
         new PlotSquared(this, "Bukkit");
         if (Settings.Enabled_Components.METRICS) {
             this.startMetrics();

Bukkit/src/main/java/com/github/intellectualsites/plotsquared/bukkit/listeners/PlayerEvents.java

@@ -24,6 +24,7 @@ import org.bukkit.block.data.BlockData;
 import org.bukkit.block.data.type.Piston;
 import org.bukkit.command.PluginCommand;
 import org.bukkit.entity.*;
+import org.bukkit.event.Event;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
@@ -1516,6 +1517,7 @@ import java.util.regex.Pattern;
         PlotInventory inventory = pp.getMeta("inventory");
         if (inventory != null && event.getRawSlot() == event.getSlot()) {
             if (!inventory.onClick(event.getSlot())) {
+                event.setResult(Event.Result.DENY);
                 event.setCancelled(true);
                 inventory.close();
             }

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/PlotSquared.java

@@ -314,8 +314,12 @@ import java.util.zip.ZipInputStream;
         if (message == null || message.toString().isEmpty()) {
             return;
         }
+        if (PlotSquared.get() == null || PlotSquared.get().getLogger() == null) {
+            System.out.printf("[P2][Info] %s\n", StringMan.getString(message));
+        } else {
             PlotSquared.get().getLogger().log(StringMan.getString(message));
         }
+    }
 
     /**
      * Log a message to the IPlotMain logger.
@@ -325,7 +329,11 @@ import java.util.zip.ZipInputStream;
      */
     public static void debug(@Nullable Object message) {
         if (Settings.DEBUG) {
-            PlotSquared.log(message);
+            if (PlotSquared.get() == null || PlotSquared.get().getLogger() == null) {
+                System.out.printf("[P2][Debug] %s\n", StringMan.getString(message));
+            } else {
+                PlotSquared.get().getLogger().log(StringMan.getString(message));
+            }
         }
     }
 

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/listener/PlotListener.java

@@ -128,20 +128,20 @@ public class PlotListener {
 
                 Optional<Integer> musicFlag = plot.getFlag(Flags.MUSIC);
                 if (musicFlag.isPresent()) {
-                    Integer id = musicFlag.get();
+                    Number id = musicFlag.get();
-                    if ((id >= 2256 && id <= 2267) || (id == 0)) {
+                    if ((id.intValue() >= 2256 && id.intValue() <= 2267) || (id.intValue() == 0)) {
                         Location loc = player.getLocation();
                         Location lastLoc = player.getMeta("music");
                         if (lastLoc != null) {
                             player.playMusic(lastLoc, 0);
-                            if (id == 0) {
+                            if (id.intValue() == 0) {
                                 player.deleteMeta("music");
                             }
                         }
-                        if (id != 0) {
+                        if (id.intValue() != 0) {
                             try {
                                 player.setMeta("music", loc);
-                                player.playMusic(loc, id);
+                                player.playMusic(loc, id.intValue());
                             } catch (Exception ignored) {
                             }
                         }

Core/src/main/java/com/github/intellectualsites/plotsquared/plot/util/StringMan.java

@@ -45,19 +45,19 @@ public class StringMan {
             return (String) obj;
         }
         if (obj.getClass().isArray()) {
-            String result = "";
+            StringBuilder result = new StringBuilder();
             String prefix = "";
 
             for (int i = 0; i < Array.getLength(obj); i++) {
-                result += prefix + getString(Array.get(obj, i));
+                result.append(prefix).append(getString(Array.get(obj, i)));
                 prefix = ",";
             }
             return "( " + result + " )";
         } else if (obj instanceof Collection<?>) {
-            String result = "";
+            StringBuilder result = new StringBuilder();
             String prefix = "";
             for (Object element : (Collection<?>) obj) {
-                result += prefix + getString(element);
+                result.append(prefix).append(getString(element));
                 prefix = ",";
             }
             return "[ " + result + " ]";