undo/redo for editing item shortcuts

src/scenario/scenario.cpp

@@ -649,4 +649,15 @@ std::string cScenario::get_sdf_name(int row, int col) {
 	if(sdf_names[row].find(col) == sdf_names[row].end())
 		return "";
 	return sdf_names[row][col];
-}
+}
+
+bool cScenario::cItemStorage::operator==(const cScenario::cItemStorage& other) const {
+	CHECK_EQ(other, ter_type);
+	CHECK_EQ(other, property);
+	for(int i = 0; i < 10; ++i){
+		if(item_num[i] != other.item_num[i]) return false;
+		if(item_odds[i] != other.item_odds[i]) return false;
+	}
+
+	return true;
+}

src/scenario/scenario.hpp

@@ -87,6 +87,8 @@ public:
 		short property;
 		cItemStorage();
 		cItemStorage& operator = (legacy::item_storage_shortcut_type& old);
+		bool operator==(const cItemStorage& other) const;
+		bool operator!=(const cItemStorage& other) { return !(*this == other); }
 	};
 	void destroy_terrain();
 public: