Backfill slots when dropping

characters/player/Player.gd

@@ -82,6 +82,12 @@ func _act_drop():
 		return
 	var child = $ItemHolder1.get_child(0)
 	child.drop(self, direction * 10)
+	
+	if $ItemHolder2.get_child_count() > 0:
+		# backfill the child
+		var new_child = $ItemHolder2.get_child(0)
+		$ItemHolder2.remove_child(new_child)
+		$ItemHolder1.add_child(new_child)
 
 var press_area_press = null