Use chest-access for inventory minecart interactions

config/checkstyle/import-control.xml

@@ -24,6 +24,7 @@
     </subpackage>
 
     <subpackage name="bukkit">
+      <allow pkg="org.mockito"/>
       <allow pkg="org.bukkit"/>
       <allow pkg="org.bstats.bukkit"/>
       <allow pkg="org.bstats.charts"/>

gradle/libs.versions.toml

@@ -40,6 +40,7 @@ flyway-core = "org.flywaydb:flyway-core:3.0"
 commandbook = "com.sk89q:commandbook:2.3"
 
 hamcrest-library = "org.hamcrest:hamcrest-library:2.2"
+mockito-core = "org.mockito:mockito-core:5.22.0"
 
 # Mojang-provided libraries, CHECK AGAINST MINECRAFT for versions
 guava = "com.google.guava:guava:33.6.0-jre"

worldguard-bukkit/build.gradle.kts

@@ -23,6 +23,9 @@ dependencies {
 
     "implementation"(libs.paperLib)
     "implementation"(libs.bstats.bukkit)
+
+    "testImplementation"(libs.paperApi)
+    "testImplementation"(libs.mockito.core)
 }
 
 tasks.named<Copy>("processResources") {

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

@@ -56,6 +56,7 @@
 import org.bukkit.entity.ExperienceOrb;
 import org.bukkit.entity.Item;
 import org.bukkit.entity.ItemFrame;
+import org.bukkit.entity.Minecart;
 import org.bukkit.entity.Player;
 import org.bukkit.entity.SulfurCube;
 import org.bukkit.entity.Tameable;
@@ -66,8 +67,10 @@
 import org.bukkit.event.entity.PlayerLeashEntityEvent;
 import org.bukkit.event.inventory.InventoryMoveItemEvent;
 import org.bukkit.event.inventory.InventoryOpenEvent;
+import org.bukkit.event.player.PlayerInteractEntityEvent;
 import org.bukkit.event.player.PlayerTakeLecternBookEvent;
 import org.bukkit.event.vehicle.VehicleExitEvent;
+import org.bukkit.inventory.InventoryHolder;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -423,7 +426,10 @@ public void onUseEntity(UseEntityEvent event) {
                     && ((ItemFrame) entity).getItem().getType() != Material.AIR) {
                 canUse = query.testBuild(BukkitAdapter.adapt(target), associable, combine(event, Flags.ITEM_FRAME_ROTATE));
                 what = "change that";
-            } else if (event.getOriginalEvent() instanceof InventoryOpenEvent || event.getOriginalEvent() instanceof InventoryMoveItemEvent) {
+            } else if (event.getOriginalEvent() instanceof InventoryOpenEvent
+                    || event.getOriginalEvent() instanceof InventoryMoveItemEvent
+                    || (event.getOriginalEvent() instanceof PlayerInteractEntityEvent
+                    && entity instanceof Minecart && entity instanceof InventoryHolder)) {
                 canUse = query.testBuild(BukkitAdapter.adapt(target), associable, combine(event, Flags.CHEST_ACCESS));
                 what = "open that";
             } else {

worldguard-bukkit/src/test/java/com/sk89q/worldguard/bukkit/listener/RegionProtectionListenerTest.java

@@ -0,0 +1,136 @@
+/*
+ * WorldGuard, a suite of tools for Minecraft
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldGuard team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldguard.bukkit.listener;
+
+import com.sk89q.worldedit.bukkit.BukkitAdapter;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldguard.WorldGuard;
+import com.sk89q.worldguard.bukkit.WorldGuardPlugin;
+import com.sk89q.worldguard.bukkit.cause.Cause;
+import com.sk89q.worldguard.bukkit.event.entity.UseEntityEvent;
+import com.sk89q.worldguard.internal.platform.WorldGuardPlatform;
+import com.sk89q.worldguard.protection.RegionResultSet;
+import com.sk89q.worldguard.protection.flags.Flags;
+import com.sk89q.worldguard.protection.flags.StateFlag.State;
+import com.sk89q.worldguard.protection.regions.ProtectedCuboidRegion;
+import com.sk89q.worldguard.protection.regions.RegionContainer;
+import com.sk89q.worldguard.protection.regions.RegionQuery;
+import org.bukkit.Location;
+import org.bukkit.World;
+import org.bukkit.entity.ArmorStand;
+import org.bukkit.entity.Entity;
+import org.bukkit.entity.EntityType;
+import org.bukkit.entity.Minecart;
+import org.bukkit.entity.minecart.HopperMinecart;
+import org.bukkit.entity.minecart.StorageMinecart;
+import org.bukkit.event.Event;
+import org.bukkit.event.inventory.InventoryMoveItemEvent;
+import org.bukkit.event.inventory.InventoryOpenEvent;
+import org.bukkit.event.player.PlayerInteractEntityEvent;
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.CALLS_REAL_METHODS;
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.mockStatic;
+import static org.mockito.Mockito.when;
+
+class RegionProtectionListenerTest {
+
+    @Test
+    void chestAccessAllowsInitialInventoryMinecartClick() {
+        assertFalse(checkUse(StorageMinecart.class, EntityType.CHEST_MINECART,
+                PlayerInteractEntityEvent.class, State.ALLOW));
+        assertFalse(checkUse(HopperMinecart.class, EntityType.HOPPER_MINECART,
+                PlayerInteractEntityEvent.class, State.ALLOW));
+    }
+
+    @Test
+    void chestAccessStillDeniesInventoryMinecartClick() {
+        assertTrue(checkUse(StorageMinecart.class, EntityType.CHEST_MINECART,
+                PlayerInteractEntityEvent.class, State.DENY));
+    }
+
+    @Test
+    void inventoryOpenAndTransferStillUseChestAccess() {
+        assertFalse(checkUse(StorageMinecart.class, EntityType.CHEST_MINECART,
+                InventoryOpenEvent.class, State.ALLOW));
+        assertTrue(checkUse(StorageMinecart.class, EntityType.CHEST_MINECART,
+                InventoryMoveItemEvent.class, State.DENY));
+    }
+
+    @Test
+    void chestAccessDoesNotAllowOtherEntityChanges() {
+        assertTrue(checkUse(ArmorStand.class, EntityType.ARMOR_STAND,
+                PlayerInteractEntityEvent.class, State.ALLOW));
+    }
+
+    @Test
+    void ordinaryMinecartStillDefersToMountProtection() {
+        assertFalse(checkUse(Minecart.class, EntityType.MINECART,
+                PlayerInteractEntityEvent.class, State.DENY));
+    }
+
+    private <T extends Entity> boolean checkUse(
+            Class<T> entityClass, EntityType type,
+            Class<? extends Event> eventClass, State chestAccess) {
+        ProtectedCuboidRegion region = new ProtectedCuboidRegion("test",
+                BlockVector3.at(-1, 0, -1), BlockVector3.at(1, 100, 1));
+        region.setFlag(Flags.CHEST_ACCESS, chestAccess);
+        RegionQuery query = mock(RegionQuery.class, CALLS_REAL_METHODS);
+        doReturn(new RegionResultSet(new ArrayList<>(List.of(region)), null)).when(query)
+                .getApplicableRegions(any(com.sk89q.worldedit.util.Location.class));
+
+        WorldGuard worldGuard = mock(WorldGuard.class);
+        WorldGuardPlatform platform = mock(WorldGuardPlatform.class);
+        RegionContainer container = mock(RegionContainer.class);
+        when(worldGuard.getPlatform()).thenReturn(platform);
+        when(platform.getRegionContainer()).thenReturn(container);
+        when(container.createQuery()).thenReturn(query);
+
+        World world = mock(World.class);
+        T entity = mock(entityClass);
+        when(entity.getType()).thenReturn(type);
+        when(entity.getLocation()).thenReturn(new Location(world, 0, 64, 0));
+        UseEntityEvent event = new UseEntityEvent(mock(eventClass), Cause.unknown(), entity);
+        event.setSilent(true);
+
+        var worldEditWorld = mock(com.sk89q.worldedit.world.World.class);
+        var worldEditLocation = new com.sk89q.worldedit.util.Location(
+                worldEditWorld, 0, 64, 0);
+        try (MockedStatic<WorldGuard> guard = mockStatic(WorldGuard.class);
+             MockedStatic<AbstractListener> listener = mockStatic(AbstractListener.class);
+             MockedStatic<BukkitAdapter> adapter = mockStatic(BukkitAdapter.class)) {
+            guard.when(WorldGuard::getInstance).thenReturn(worldGuard);
+            listener.when(() -> AbstractListener.isRegionSupportEnabled(world)).thenReturn(true);
+            adapter.when(() -> BukkitAdapter.adapt(any(Location.class)))
+                    .thenReturn(worldEditLocation);
+            new RegionProtectionListener(mock(WorldGuardPlugin.class)).onUseEntity(event);
+        }
+        return event.isCancelled();
+    }
+}