fix: cancel structure locate in classic plot worlds (#4653)

Author: PierreSchwang

Bukkit/src/main/java/com/plotsquared/bukkit/listener/PaperListener.java

@@ -29,6 +29,7 @@
 import com.destroystokyo.paper.event.server.AsyncTabCompleteEvent;
 import com.google.inject.Inject;
 import com.plotsquared.bukkit.util.BukkitUtil;
+import com.plotsquared.core.PlotSquared;
 import com.plotsquared.core.command.Command;
 import com.plotsquared.core.command.MainCommand;
 import com.plotsquared.core.configuration.Settings;
@@ -38,6 +39,7 @@
 import com.plotsquared.core.player.PlotPlayer;
 import com.plotsquared.core.plot.Plot;
 import com.plotsquared.core.plot.PlotArea;
+import com.plotsquared.core.plot.PlotAreaType;
 import com.plotsquared.core.plot.flag.FlagContainer;
 import com.plotsquared.core.plot.flag.implementations.BeaconEffectsFlag;
 import com.plotsquared.core.plot.flag.implementations.DoneFlag;
@@ -48,6 +50,7 @@
 import com.plotsquared.core.plot.world.PlotAreaManager;
 import com.plotsquared.core.util.PlotFlagUtil;
 import io.papermc.paper.event.entity.EntityMoveEvent;
+import io.papermc.paper.event.world.StructuresLocateEvent;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.minimessage.tag.Tag;
 import net.kyori.adventure.text.minimessage.tag.resolver.TagResolver;
@@ -458,6 +461,21 @@ public void onBeaconEffect(final BeaconEffectEvent event) {
         }
     }
 
+    /**
+     * Don't let the server die when populating cartographers (villager offering maps) in classic plot worlds
+     * (as those don't generate POIs)
+     */
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.HIGHEST)
+    public void onStructuresLocate(StructuresLocateEvent event) {
+        if (!PlotSquared.get().getPlotAreaManager().hasPlotArea(event.getWorld().getName())) {
+            return;
+        }
+        final PlotArea area = PlotSquared.get().getPlotAreaManager().getPlotAreaByString(event.getWorld().getName());
+        if (area != null && area.getType() == PlotAreaType.NORMAL) {
+            event.setCancelled(true);
+        }
+    }
+
     private boolean getBooleanFlagValue(
             @NonNull FlagContainer container,
             @NonNull Class<? extends BooleanFlag<?>> flagClass,