undo/redo for advanced town details

src/scenedit/scen.townout.cpp

@@ -1027,9 +1027,19 @@ void edit_advanced_town() {
 	
 	put_advanced_town_in_dlog(town_dlg);
 	
+	town_advanced_t old_details = advanced_from_town(cur_town, *town, scenario);
 	town_dlg.run();
-	if(town_dlg.accepted() && delete_rect)
-		scenario.store_item_rects.erase(cur_town);
+	if(town_dlg.accepted()){
+		if(delete_rect){
+			scenario.store_item_rects.erase(cur_town);
+		}
+
+		town_advanced_t new_details = advanced_from_town(cur_town, *town, scenario);
+		if(new_details != old_details){
+			undo_list.add(action_ptr(new aEditTownAdvancedDetails(cur_town, old_details, new_details)));
+			update_edit_menu();
+		}
+	}
 }
 
 static bool save_town_wand(cDialog& me, std::string, eKeyMod) {

src/scenedit/scen.undo.cpp

@@ -950,4 +950,14 @@ bool aEditTownWandering::redo_me() {
 	scenario.towns[which]->wandering = new_wandering;
 	scenario.towns[which]->wandering_locs = new_wandering_locs;
 	return true;
+}
+
+bool aEditTownAdvancedDetails::undo_me() {
+	town_set_advanced(which, *scenario.towns[which], scenario, old_details);
+	return true;
+}
+
+bool aEditTownAdvancedDetails::redo_me() {
+	town_set_advanced(which, *scenario.towns[which], scenario, new_details);
+	return true;
 }

src/scenedit/scen.undo.hpp

@@ -609,4 +609,15 @@ public:
 													new_wandering(new_wandering), new_wandering_locs(new_wandering_locs) {}
 };
 
+class aEditTownAdvancedDetails : public cAction {
+	size_t which;
+	town_advanced_t old_details;
+	town_advanced_t new_details;
+	bool undo_me() override;
+	bool redo_me() override;
+public:
+	aEditTownAdvancedDetails(size_t which, town_advanced_t old_details, town_advanced_t new_details) :
+		cAction("Edit Town Advanced Details"), which(which), old_details(old_details), new_details(new_details) {}
+};
+
 #endif