update

data/menubar.xml

@@ -83,6 +83,7 @@
         <item name="Find Item on Selection" action="SEARCH_ON_SELECTION_ITEM" help="Find items on selected area."/>
         <item name="Remove Item on Selection" action="REMOVE_ON_SELECTION_ITEM" help="Remove item on selected area."/>
         <item name="Remove Monsters on Selection" action="REMOVE_ON_SELECTION_MONSTER" help="Remove monsters on selected area."/>
+		<item name="Remove Duplicates Items on Selection" action="REMOVE_ON_SELECTION_DUPLICATE_ITEMS" help="Removes all items duplicates selected area."/>
         <separator/>
         <menu name="$Find on Selection">
             <item name="Find $Everything" action="SEARCH_ON_SELECTION_EVERYTHING" help="Find all unique/action/text/container items."/>
@@ -91,6 +92,7 @@
             <item name="Find $Action" action="SEARCH_ON_SELECTION_ACTION" help="Find all items with an action ID on selected area."/>
             <item name="Find $Container" action="SEARCH_ON_SELECTION_CONTAINER" help="Find all containers on selected area."/>
             <item name="Find $Writeable" action="SEARCH_ON_SELECTION_WRITEABLE" help="Find all writeable items on selected area."/>
+			<item name="Find $Duplicate Items" action="SEARCH_ON_SELECTION_DUPLICATE" help="Find all positions where there are duplicate items on selected area."/>
         </menu>
         <separator/>
         <menu name="$Selection Mode">

source/item.h

@@ -304,7 +304,7 @@ class Item : public ItemAttributes {
 		return getItemType().isMetaItem();
 	}
 	bool hasElevation() const {
-		return getItemType().hasElevation();
+		return getItemType().hasElevation;
 	}
 
 	// Wall alignment (vertical, horizontal, pole, corner)

source/items.h

@@ -294,9 +294,6 @@ class ItemType {
 		return is_metaitem;
 	}
 
-	bool hasElevation() const noexcept {
-		return hasElevation;
-	}
 	bool isFloorChange() const noexcept;
 
 	float getWeight() const noexcept {