奇怪的堆损坏问题

由于某种原因，我从下面的类定义文件中得到了一个奇怪的堆损坏，很可能是在"CreateFromNode"函数中。有人能帮我一下吗?既然我抓住了它，我真的很想现在就处理它，而不是让它在以后显现出来。此外，没有外部力量修改这个类的任何成员(或它的成员)。

#include "Object.h"
TmxMap::Object::Object():name(), position(), size(), gid(-1), visible(true),
properties(), image(), polygon(NULL), polyline(NULL), ellipse(false){}
TmxMap::Object::Object(rapidxml::xml_node<>* const& object_node):name(),
    position(), size(), gid(-1), visible(true), properties(), image(),
    polygon(NULL), polyline(NULL), ellipse(false){
CreateFromNode(object_node);
}
TmxMap::Object::Object(TmxMap::Object const& from):name(from.name),
    position(from.position), size(from.size), gid(from.gid),
    visible(from.visible), properties(from.properties),
    image(from.image), polygon(from.polygon), polyline(from.polyline),
    ellipse(from.ellipse){}
TmxMap::Object::~Object(){
DeleteObjects();
}
void TmxMap::Object::CreateFromNode(rapidxml::xml_node<>* const& object_node){
DeleteObjects();
rapidxml::xml_node<>* data_node = NULL;
rapidxml::xml_attribute<>* data_attrib = NULL;
if((data_attrib = object_node -> first_attribute("name")))
    name = data_attrib -> value();
if((data_attrib = object_node -> first_attribute("width")))
    size.x = std::strtol(data_attrib -> value(), NULL, 10);
if((data_attrib = object_node -> first_attribute("height")))
    size.y = std::strtol(data_attrib -> value(), NULL, 10);
position.Set(
        std::strtol(object_node -> first_attribute("x") -> value(), NULL, 10),
        std::strtol(object_node -> first_attribute("y") -> value(), NULL, 10)
);
if((data_node = object_node -> first_node("polygon")))
    polygon = new Polygon2D<int>(data_node);
if((data_node = object_node -> first_node("polyline")))
    polyline = new Polyline2D<int>(data_node);
ellipse = (object_node -> first_node("ellipse") != NULL);
}
void TmxMap::Object::DeleteObjects(){
if(polygon){delete polygon; polygon = NULL;}
if(polyline){delete polyline; polyline = NULL;}
}
void TmxMap::Object::Destroy(){
name.clear();
position.Set();
size.Set();
gid = 0;
visible = true;
properties.Destroy();
image.Destroy();
DeleteObjects();
ellipse = false;
   }