fix

src/main/java/carpet/CarpetServer.java

@@ -112,7 +112,7 @@ public class CarpetServer implements ClientModInitializer,DedicatedServerModInit
     public static void tick(MinecraftServer server)
     {
         TickSpeed.tick();
-        HUDController.update_hud(server, false);
+        HUDController.update_hud(server, null);
         scriptServer.tick();
 
         //in case something happens

src/main/java/carpet/logging/HUDController.java

@@ -19,10 +19,13 @@ import net.minecraft.world.World;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 import java.util.function.Consumer;
 
 public class HUDController
@@ -38,18 +41,18 @@ public class HUDController
         HUDListeners.add(listener);
     }
 
-    public static Map<PlayerEntity, List<BaseText>> player_huds = new HashMap<>();
+    public static Map<ServerPlayerEntity, List<BaseText>> player_huds = new HashMap<>();
     
-    public static final Map<PlayerEntity, BaseText> scarpet_headers = new HashMap<>();
+    public static final Map<ServerPlayerEntity, BaseText> scarpet_headers = new HashMap<>();
     
-    public static final Map<PlayerEntity, BaseText> scarpet_footers = new HashMap<>();
+    public static final Map<ServerPlayerEntity, BaseText> scarpet_footers = new HashMap<>();
 
     public static void resetScarpetHUDs() {
         scarpet_headers.clear();
         scarpet_footers.clear();
     }
 
-    public static void addMessage(PlayerEntity player, BaseText hudMessage)
+    public static void addMessage(ServerPlayerEntity player, BaseText hudMessage)
     {
         if (!player_huds.containsKey(player))
         {
@@ -70,9 +73,9 @@ public class HUDController
     }
 
 
-    public static void update_hud(MinecraftServer server, boolean force)
+    public static void update_hud(MinecraftServer server, List<ServerPlayerEntity> force)
     {
-        if ((server.getTicks() % 20 != 0 && !force) || CarpetServer.minecraft_server == null)
+        if (((server.getTicks() % 20 != 0) && force == null) || CarpetServer.minecraft_server == null)
             return;
 
         player_huds.clear();
@@ -109,12 +112,14 @@ public class HUDController
         // extensions have time to pitch in.
         HUDListeners.forEach(l -> l.accept(server));
 
-        for (PlayerEntity player: player_huds.keySet())
+        Set<ServerPlayerEntity> targets = new HashSet<>(player_huds.keySet());
+        if (force!= null) targets.addAll(force);
+        for (ServerPlayerEntity player: targets)
         {
             PlayerListHeaderS2CPacket packet = new PlayerListHeaderS2CPacket();
             ((PlayerListHeaderS2CPacketMixin)packet).setHeader(scarpet_headers.getOrDefault(player, new LiteralText("")));
-            ((PlayerListHeaderS2CPacketMixin)packet).setFooter(Messenger.c(player_huds.get(player).toArray(new Object[0])));
-            ((ServerPlayerEntity)player).networkHandler.sendPacket(packet);
+            ((PlayerListHeaderS2CPacketMixin)packet).setFooter(Messenger.c(player_huds.getOrDefault(player, Collections.emptyList()).toArray(new Object[0])));
+            player.networkHandler.sendPacket(packet);
         }
     }
     private static BaseText [] send_tps_display(MinecraftServer server)

src/main/java/carpet/script/api/Auxiliary.java

@@ -571,35 +571,43 @@ public class Auxiliary {
             if (action != Action.CLEAR && lv.size() < 3)
                 throw new InternalExpressionException("Third argument of 'display_title' must be present except for 'clear' type");
             Text title;
+            boolean soundsTrue = false;
             if (lv.size() > 2)
             {
                 pVal = lv.get(2).evalValue(c);
                 if (pVal instanceof FormattedTextValue)
+                {
                     title = ((FormattedTextValue) pVal).getText();
+                    soundsTrue = !title.asString().isEmpty();
+                }
                 else
+                {
                     title = new LiteralText(pVal.getString());
+                    soundsTrue = pVal.getBoolean();
+                }
             }
             else title = null; // Will never happen, just to make lambda happy
             if (action == null)
             {
-                Map<PlayerEntity, BaseText> map;
+                Map<ServerPlayerEntity, BaseText> map;
                 if (actionString.equals("player_list_header"))
                     map = HUDController.scarpet_headers;
                 else
                     map = HUDController.scarpet_footers;
                 
                 AtomicInteger total = new AtomicInteger(0);
-                if (!lv.get(2).evalValue(c).getBoolean()) // null or empty string
-                    targets.forEach(target -> {
+                List<ServerPlayerEntity> targetList = targets.collect(Collectors.toList());
+                if (!soundsTrue) // null or empty string
+                    targetList.forEach(target -> {
                         map.remove(target);
                         total.getAndIncrement();
                     });
                 else
-                    targets.forEach(target -> {
+                    targetList.forEach(target -> {
                         map.put(target, (BaseText) title);
                         total.getAndIncrement();
                     });
-                HUDController.update_hud(((CarpetContext)c).s.getMinecraftServer(), true);
+                HUDController.update_hud(((CarpetContext)c).s.getMinecraftServer(), targetList);
                 Value ret = NumericValue.of(total.get());
                 return (cc, tt) -> ret;
             }