undo/redo for editing/clearing a special item

src/scenario/item.cpp

@@ -1444,4 +1444,12 @@ bool cItem::operator==(const cItem& other) {
 	CHECK_EQ(other, rechargeable);
 	CHECK_EQ(other, desc);
 	return true;
+}
+
+bool cSpecItem::operator==(const cSpecItem& other) {
+	CHECK_EQ(other, flags);
+	CHECK_EQ(other, special);
+	CHECK_EQ(other, name);
+	CHECK_EQ(other, descr);
+	return true;
 }

src/scenario/item.hpp

@@ -99,6 +99,10 @@ public:
 	short special = -1;
 	std::string name;
 	std::string descr;
+
+	// For detecting actual changes to special items in the scenario editor
+	bool operator==(const cSpecItem& other);
+	bool operator!=(const cSpecItem& other) { return !(*this == other); }
 };
 
 #endif