put [resource] before other content (again); fixes #3345

Now content that is loaded via [load_resource] is placed to the position
where the [load_resource] was. This fixes a problem where previously one could
not use lua variables/functions created by the [resource][lua] because the
engine would put the [lua] tags from the [resource] after the [resource] from the
scenario.

This time it uses size_t indicies instad of vector iterators to prevent
possible bugs arisong from invalidating iterators when the size of the
vector changes.

This reverts commit b3e1680.

In the long run i think it might actually be better to allow [event] and
[lua] to have a order/priority attribute similar to lua on_event events.
Then this commit would probably not be needed anymore.

src/config.cpp

@@ -542,6 +542,55 @@ config& config::add_child_at(config_key_type key, const config& val, unsigned in
 	return *v[index];
 }
 
+size_t config::find_total_first_of(config_key_type key, size_t start)
+{
+	assert(start <= ordered_children.size());
+	const size_t npos = static_cast<size_t>(-1);
+
+	auto pos = std::find_if(ordered_begin() + start, ordered_end(), [&](const config::any_child& can){ return can.key == key; });
+
+	if(pos == ordered_end()) {
+		return npos;
+	}
+
+	return static_cast<size_t>(pos - ordered_begin());
+}
+
+config& config::add_child_at_total(config_key_type key, const config &val, size_t pos)
+{
+	assert(pos <= ordered_children.size());
+	if(pos == ordered_children.size()) {
+		//optimisation
+		config::add_child(key, val);
+	}
+
+	auto end = ordered_children.end();
+	auto pos_it = ordered_children.begin() + pos;
+	auto next = std::find_if(pos_it, end,[&](const child_pos& p){ return p.pos->first == key; });
+
+	if(next == end) {
+		config& res = config::add_child(key, val);
+		std::rotate(ordered_children.begin() + pos, ordered_children.end(), ordered_children.end());
+		return res;
+	}
+
+	auto pl = next->pos;
+	child_list& l = pl->second;
+	unsigned int index = next->index;
+	config& res = **(l.emplace(l.begin() + index, new config(val)));
+
+	for(auto ord = next; ord != end; ++ord) {
+		//this changes next->index and all later refernces to that tag.
+		if(ord->pos == pl) {
+			++ord->index;
+		}
+	}
+
+	//finally insert our new child in ordered_children.
+	ordered_children.insert(pos_it, { pl, index });
+	return res;
+}
+
 namespace
 {
 struct remove_ordered

src/config.hpp

@@ -624,7 +624,7 @@ class config
 		typedef std::vector<child_pos>::const_iterator Itor;
 		typedef const_all_children_iterator this_type;
 		explicit const_all_children_iterator(const Itor &i): i_(i) {}
-		const_all_children_iterator(all_children_iterator& i): i_(i.i_) {}
+		const_all_children_iterator(const all_children_iterator& i): i_(i.i_) {}
 
 		const_all_children_iterator &operator++() { ++i_; return *this; }
 		const_all_children_iterator operator++(int) { return const_all_children_iterator(i_++); }
@@ -659,6 +659,11 @@ class config
 		friend class config;
 	};
 
+	/// here pos is the index of the new child in _all_ childs, while in add_child_at
+	/// it is the index of the new child within all chils of type @key.
+	config& add_child_at_total(config_key_type key, const config &val, size_t pos);
+	size_t find_total_first_of(config_key_type key, size_t start = 0);
+
 	typedef boost::iterator_range<all_children_iterator> all_children_itors;
 	typedef boost::iterator_range<const_all_children_iterator> const_all_children_itors;
 

src/saved_game.cpp

@@ -298,7 +298,7 @@ struct modevents_entry
 
 } // end anon namespace
 
-void saved_game::load_mod(const std::string& type, const std::string& id)
+void saved_game::load_mod(const std::string& type, const std::string& id, size_t pos)
 {
 	if(const config& cfg = game_config_manager::get()->game_config().find_child(type, "id", id)) {
 		// Note the addon_id if this mod is required to play the game in mp.
@@ -323,18 +323,18 @@ void saved_game::load_mod(const std::string& type, const std::string& id)
 			if(modevent["enable_if"].empty()
 				|| variable_to_bool(carryover_.child_or_empty("variables"), modevent["enable_if"])
 			) {
-				this->starting_point_.add_child("event", modevent);
+				this->starting_point_.add_child_at_total("event", modevent, pos++);
 			}
 		}
 
 		// Copy lua
 		for(const config& modlua : cfg.child_range("lua")) {
-			this->starting_point_.add_child("lua", modlua);
+			this->starting_point_.add_child_at_total("lua", modlua, pos++);
 		}
 
 		// Copy load_resource
 		for(const config& load_resource : cfg.child_range("load_resource")) {
-			this->starting_point_.add_child("load_resource", load_resource);
+			this->starting_point_.add_child_at_total("load_resource", load_resource, pos++);
 		}
 	} else {
 		// TODO: A user message instead?
@@ -367,25 +367,20 @@ void saved_game::expand_mp_events()
 			mods.emplace_back("campaign", classification_.campaign);
 		}
 
-		// In the first iteration mod contains no [resource]s in all other iterations, mods contains only [resource]s.
-		do {
-			for(modevents_entry& mod : mods) {
-				load_mod(mod.type, mod.id);
-			}
-
-			mods.clear();
-
-			for(const config& cfg : starting_point_.child_range("load_resource")) {
-				if(loaded_resources.find(cfg["id"].str()) == loaded_resources.end()) {
-					mods.emplace_back("resource", cfg["id"].str());
-
-					loaded_resources.insert(cfg["id"].str());
-				}
+		for(modevents_entry& mod : mods) {
+			load_mod(mod.type, mod.id, starting_point_.all_children_count());
+		}
+		mods.clear();
+
+		while(starting_point_.has_child("load_resource")) {
+			std::string id = starting_point_.child("load_resource")["id"];
+			size_t pos = starting_point_.find_total_first_of("load_resource");
+			starting_point_.remove_child("load_resource", 0);
+			if(loaded_resources.find(id) == loaded_resources.end()) {
+				loaded_resources.insert(id);
+				load_mod("resource", id, pos);
 			}
-
-			starting_point_.clear_children("load_resource");
-		} while(!mods.empty());
-
+		}
 		this->starting_point_["has_mod_events"] = true;
 	}
 }

src/saved_game.hpp

@@ -72,7 +72,7 @@ class saved_game
 	/// should be called after expand_scenario() but before expand_carryover()
 	void expand_mp_events();
 	/// helper for expand_mp_events();
-	void load_mod(const std::string& type, const std::string& id);
+	void load_mod(const std::string& type, const std::string& id, size_t pos);
 	/// adds values of [option]s into [carryover_sides_start][variables] so that they are applied in the next level.
 	/// Note that since [variabels] are persistent we only use this once at the beginning
 	/// of a campaign but calling it multiple times is no harm eigher