Revert USE flag's functionality to 5.x, add new INTERACT flag.

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

@@ -254,22 +254,27 @@ public boolean apply(Location target) {
 
                 /* Inventory */
                 } else if (Materials.isInventoryBlock(type)) {
-                    canUse = query.testBuild(target, associable, DefaultFlag.USE, DefaultFlag.CHEST_ACCESS);
+                    canUse = query.testBuild(target, associable, DefaultFlag.INTERACT, DefaultFlag.CHEST_ACCESS);
                     what = "open that";
 
                 /* Beds */
                 } else if (type == Material.BED_BLOCK) {
-                    canUse = query.testBuild(target, associable, DefaultFlag.USE, DefaultFlag.SLEEP);
+                    canUse = query.testBuild(target, associable, DefaultFlag.INTERACT, DefaultFlag.SLEEP);
                     what = "sleep";
 
                 /* TNT */
                 } else if (type == Material.TNT) {
-                    canUse = query.testBuild(target, associable, DefaultFlag.TNT);
+                    canUse = query.testBuild(target, associable, DefaultFlag.INTERACT, DefaultFlag.TNT);
                     what = "use explosives";
 
+                /* Legacy USE flag */
+                } else if (Materials.isUseFlagApplicable(type)) {
+                    canUse = query.testBuild(target, associable, DefaultFlag.INTERACT, DefaultFlag.USE);
+                    what = "use that";
+
                 /* Everything else */
                 } else {
-                    canUse = query.testBuild(target, associable, DefaultFlag.USE);
+                    canUse = query.testBuild(target, associable, DefaultFlag.INTERACT);
                     what = "use that";
                 }
 
@@ -383,7 +388,7 @@ public void onUseEntity(UseEntityEvent event) {
 
         /* Everything else */
         } else {
-            canUse = query.testBuild(target, associable, DefaultFlag.USE);
+            canUse = query.testBuild(target, associable, DefaultFlag.INTERACT);
             what = "use that";
         }
 
@@ -438,7 +443,7 @@ public void onDamageEntity(DamageEntityEvent event) {
 
         /* Everything else */
         } else {
-            canDamage = query.testBuild(target, associable, DefaultFlag.USE);
+            canDamage = query.testBuild(target, associable, DefaultFlag.INTERACT);
             what = "hit that";
         }
 
@@ -458,7 +463,7 @@ public void onVehicleExit(VehicleExitEvent event) {
             if (!isWhitelisted(Cause.create(player), vehicle.getWorld())) {
                 RegionQuery query = getPlugin().getRegionContainer().createQuery();
                 Location location = vehicle.getLocation();
-                if (!query.testBuild(location, player, DefaultFlag.USE)) {
+                if (!query.testBuild(location, player, DefaultFlag.INTERACT)) {
                     long now = System.currentTimeMillis();
                     Long lastTime = WGMetadata.getIfPresent(player, DISEMBARK_MESSAGE_KEY, Long.class);
                     if (lastTime == null || now - lastTime >= LAST_MESSAGE_DELAY) {

src/main/java/com/sk89q/worldguard/bukkit/util/Materials.java

@@ -21,6 +21,7 @@
 
 import com.google.common.collect.BiMap;
 import com.google.common.collect.HashBiMap;
+import com.sk89q.worldguard.protection.flags.DefaultFlag;
 import org.bukkit.DyeColor;
 import org.bukkit.Material;
 import org.bukkit.entity.EntityType;
@@ -576,6 +577,40 @@ public static boolean isInventoryBlock(Material material) {
                 || material == Material.DROPPER;
     }
 
+    /**
+     * Test whether the given material is affected by
+     * {@link DefaultFlag#USE}.
+     *
+     * <p>Generally, materials that are considered by this method are those
+     * that are not inventories but can be used.</p>
+     *
+     * @param material the material
+     * @return true if covered by the use flag
+     */
+    public static boolean isUseFlagApplicable(Material material) {
+        return material == Material.LEVER
+                || material == Material.STONE_BUTTON
+                || material == Material.WOOD_BUTTON
+                || material == Material.NOTE_BLOCK
+                || material == Material.DIODE_BLOCK_OFF
+                || material == Material.DIODE_BLOCK_ON
+                || material == Material.WOODEN_DOOR
+                || material == Material.TRAP_DOOR
+                || material == Material.FENCE_GATE
+                || material == Material.JUKEBOX
+                || material == Material.DISPENSER
+                || material == Material.FURNACE
+                || material == Material.BURNING_FURNACE
+                || material == Material.WORKBENCH
+                || material == Material.BREWING_STAND
+                || material == Material.ENCHANTMENT_TABLE
+                || material == Material.CAULDRON
+                || material == Material.BEACON
+                || material == Material.ANVIL
+                || material == Material.HOPPER
+                || material == Material.DROPPER;
+    }
+
     /**
      * Test whether the given type is Redstone ore.
      *

src/main/java/com/sk89q/worldguard/protection/flags/DefaultFlag.java

@@ -47,6 +47,7 @@ public final class DefaultFlag {
     public static final StateFlag BLOCK_BREAK = new StateFlag("block-break", false);
     public static final StateFlag BLOCK_PLACE = new StateFlag("block-place", false);
     public static final StateFlag USE = new StateFlag("use", false);
+    public static final StateFlag INTERACT = new StateFlag("interact", false);
     public static final StateFlag PVP = new StateFlag("pvp", false);
     public static final StateFlag SLEEP = new StateFlag("sleep", false);
     public static final StateFlag TNT = new StateFlag("tnt", false);
@@ -128,7 +129,7 @@ public final class DefaultFlag {
 
     public static final Flag<?>[] flagsList = new Flag<?>[] {
             PASSTHROUGH, BUILD, CONSTRUCT, BLOCK_BREAK, BLOCK_PLACE, PVP, CHEST_ACCESS, PISTONS,
-            TNT, LIGHTER, USE, PLACE_VEHICLE, DESTROY_VEHICLE, SLEEP,
+            TNT, LIGHTER, USE, INTERACT, PLACE_VEHICLE, DESTROY_VEHICLE, SLEEP,
             MOB_DAMAGE, MOB_SPAWNING, DENY_SPAWN, INVINCIBILITY, EXP_DROPS,
             CREEPER_EXPLOSION, OTHER_EXPLOSION, ENDERDRAGON_BLOCK_DAMAGE, GHAST_FIREBALL, ENDER_BUILD,
             DENY_MESSAGE, GREET_MESSAGE, FAREWELL_MESSAGE, NOTIFY_ENTER, NOTIFY_LEAVE,