fix bug #22484 (fix random map generation in mp create)

As described in bug report, mp create had a bizarre implementation
for random map vs scenario generation. Scenario generation was called
map generation, and map generation was impossible. We fix it and make
it work like it works in the rest of the game.

At time of writing the wiki describes map generation wml as follows:

```
To use the default [generator] your [scenario] tag must contain one of
the following keys:

scenario_generation=default
map_generation=default

If ‘scenario_generation’ is used, the engine will expect for your entire
[scenario] sub tags to be inside a [scenario] tag inside [generator].
Tags outside of this will be ignored. There may be value in this, but at
this writing, it’s not clear. ‘map_generation=default’ is simpler and
more commonly used. It is also necessary to use this key so that you can
regenerate a map in MP game creation. In its use only generator data is
in the [generator] tag, all other [scenario] data is placed outside of it.
The exception is if you are making an initial MP scenario available in MP
game creation, for this a [scenario] tag must appear inside of
[generator], containing the [scenario] subtags you want to use.
See “data/multiplayer/scenarios/Random_Scenario.cfg” for an example.
```

This commit essentially removes the "exception" pointed out above.
After this, the mp create dialog treats map and scenario generation
both in the "random maps" classification, and it handles them normally,
scenario generation replacing the entire scenario, and map generation
replacing only the map data of the scenario.

data/multiplayer/scenarios/Random_Scenario.cfg

@@ -5,7 +5,7 @@
     id=multiplayer_Random_Map
     name= _ "Random map"
     description= _ "Randomly generated map. Note: random maps are often unbalanced, but if you have time, you can regenerate them until you get a good one."
-    map_generation=default
+    scenario_generation=default
     [generator]
         [scenario]
             name= _ "Random map"

data/multiplayer/scenarios/Random_Scenario_Desert.cfg

@@ -4,7 +4,7 @@
     id=multiplayer_Random_Map_Desert
     name= _ "Random map (Desert)"
     description= _ "A random map with sand as the primary terrain. Note: random maps are often unbalanced, but if you have time, you can regenerate them until you get a good one."
-    map_generation=default
+    scenario_generation=default
     [generator]
         [scenario]
             name= _ "Random map (Desert)"

data/multiplayer/scenarios/Random_Scenario_Marsh.cfg

@@ -4,7 +4,7 @@
     id=multiplayer_Random_Map_Marsh
     name= _ "Random map (Marsh)"
     description= _ "A random map with swamp as the primary terrain. Note: random maps are often unbalanced, but if you have time, you can regenerate them until you get a good one."
-    map_generation=default
+    scenario_generation=default
     [generator]
         [scenario]
             name= _ "Random map (Marsh)"

data/multiplayer/scenarios/Random_Scenario_Winter.cfg

@@ -4,7 +4,7 @@
     id=multiplayer_Random_Map_Winter
     name= _ "Random map (Winter)"
     description= _ "A random map set in the break between spring and winter, mainly with snowy terrains. Note: random maps are often unbalanced, but if you have time, you can regenerate them until you get a good one."
-    map_generation=default
+    scenario_generation=default
     [generator]
         [scenario]
             name= _ "Random map (Winter)"

data/multiplayer/scenarios/Random_YAMG_Scenario.cfg

@@ -5,7 +5,7 @@
     id=multiplayer_Random_YAMG_Map
     name= _ "Random map by YAMG"
     description= _ "Randomly generated map. Note: random maps are often unbalanced, but if you have time, you can regenerate them until you get a good one."
-    map_generation=yamg
+    scenario_generation=yamg
     [generator]
         [scenario]
             name= _ "Random map"

src/game_initialization/create_engine.cpp

@@ -42,6 +42,7 @@ static lg::log_domain log_config("config");
 #define ERR_CF LOG_STREAM(err, log_config)
 
 static lg::log_domain log_mp_create_engine("mp/create/engine");
+#define WRN_MP LOG_STREAM(warn, log_mp_create_engine)
 #define DBG_MP LOG_STREAM(debug, log_mp_create_engine)
 
 namespace {
@@ -251,10 +252,27 @@ std::string user_map::id() const
 	return name_;
 }
 
-random_map::random_map(const config& generator_data) :
-	scenario(config()),
-	generator_data_(generator_data)
-{
+random_map::random_map(const config& data) :
+	scenario(data),
+	generator_data_(),
+	generate_whole_scenario_(data_.has_attribute("scenario_generation")),
+	generator_name_(generate_whole_scenario_ ? data_["scenario_generation"] : data_["map_generation"])
+{
+	if (!data.has_child("generator")) {
+		data_ = config();
+		generator_data_= config();
+		data_["description"] = "Error: Random map found with missing generator information. Scenario should have a [generator] child.";
+		data_["error_message"] = "missing [generator] tag";
+	} else {
+		generator_data_ = data.child("generator");
+	}
+
+	if (!data.has_attribute("scenario_generation") && !data.has_attribute("map_generation")) {
+		data_ = config();
+		generator_data_= config();
+		data_["description"] = "Error: Random map found with missing generator information. Scenario should have a [generator] child.";
+		data_["error_message"] = "couldn't find 'scenario_generation' or 'map_generation' attribute";
+	}
 }
 
 random_map::~random_map()
@@ -268,17 +286,32 @@ const config& random_map::generator_data() const
 
 std::string random_map::name() const
 {
-	return generator_data_["name"];
+	return data_["name"];
 }
 
 std::string random_map::description() const
 {
-	return generator_data_["description"];
+	return data_["description"];
 }
 
 std::string random_map::id() const
 {
-	return generator_data_["id"];
+	return data_["id"];
+}
+
+bool random_map::generate_whole_scenario() const
+{
+	return generate_whole_scenario_;
+}
+
+std::string random_map::generator_name() const
+{
+	return generator_name_;
+}
+
+map_generator * random_map::create_map_generator() const
+{
+	return ::create_map_generator(generator_name(), generator_data());
 }
 
 campaign::campaign(const config& data) :
@@ -427,16 +460,47 @@ void create_engine::init_generated_level_data()
 {
 	DBG_MP << "initializing generated level data\n";
 
-	config data = generator_->create_scenario();
+	//DBG_MP << "current data:\n";
+	//DBG_MP << current_level().data().debug();
+
+	random_map * cur_lev = dynamic_cast<random_map *> (&current_level());
+
+	if (!cur_lev) {
+		WRN_MP << "Tried to initialized generated level data on a level that wasn't a random map\n";
+		return;
+	}
+
+	if (!cur_lev->generate_whole_scenario())
+	{
+		DBG_MP << "** replacing map ** \n";
+
+		config data = cur_lev->data();
+
+		data["map_data"] = generator_->create_map();
 
-	// Set the scenario to have placing of sides
-	// based on the terrain they prefer
-	data["modify_placing"] = "true";
+		cur_lev->set_data(data);
+
+	} else { //scenario generation
+
+		DBG_MP << "** replacing scenario ** \n";
+
+		config data = generator_->create_scenario();
+
+		// Set the scenario to have placing of sides
+		// based on the terrain they prefer
+		if (!data.has_attribute("modify_placing")) {
+			data["modify_placing"] = "true";
+		}
+
+		const std::string& description = cur_lev->data()["description"];
+		data["description"] = description;
+
+		cur_lev->set_data(data);
+	}
 
-	const std::string& description = current_level().data()["description"];
-	data["description"] = description;
+	//DBG_MP << "final data:\n";
+	//DBG_MP << current_level().data().debug();
 
-	current_level().set_data(data);
 }
 
 void create_engine::prepare_for_new_level()
@@ -579,6 +643,7 @@ void create_engine::prepare_for_saved_game()
 
 void create_engine::prepare_for_other()
 {
+	DBG_MP << "prepare_for_other\n";
 	state_.set_scenario(current_level().data());
 	state_.mp_settings().hash = current_level().data().hash();
 }
@@ -735,9 +800,7 @@ void create_engine::set_current_level(const size_t index)
 		random_map* current_random_map =
 			dynamic_cast<random_map*>(&current_level());
 
-		generator_.reset(create_map_generator(
-			current_random_map->generator_data()["map_generation"],
-			current_random_map->generator_data().child("generator")));
+		generator_.reset(current_random_map->create_map_generator());
 	} else {
 		generator_.reset(NULL);
 	}
@@ -998,7 +1061,7 @@ void create_engine::init_all_levels()
 		if (!data["allow_new_game"].to_bool(true))
 			continue;
 
-		if (!data["map_generation"].empty()) {
+		if (data.has_attribute("map_generation") || data.has_attribute("scenario_generation")) {
 			random_map_ptr new_random_map(new random_map(data));
 			random_maps_.push_back(new_random_map);
 			random_maps_.back()->set_metadata();

src/game_initialization/create_engine.hpp

@@ -108,20 +108,28 @@ class user_map : public scenario
 class random_map : public scenario
 {
 public:
-	random_map(const config& generator_data);
+	random_map(const config& data);
 	virtual ~random_map();
 
 	const config& generator_data() const;
 
 	std::string name() const;
 	std::string description() const;
 	std::string id() const;
+	std::string generator_name() const;
+
+	map_generator * create_map_generator() const;
+
+	bool generate_whole_scenario() const;
 
 private:
 	random_map(const random_map&);
 	void operator=(const random_map&);
 
 	config generator_data_;
+
+	bool generate_whole_scenario_;
+	std::string generator_name_;
 };
 
 class campaign : public level

src/tests/gui/test_gui2.cpp

@@ -820,7 +820,7 @@ struct twrapper<gui2::teditor_generate_map>
 
 		std::vector<map_generator*> map_generators;
 		BOOST_FOREACH(const config &i, main_config.child_range("multiplayer")) {
-			if(i["map_generation"] == "default") {
+			if(i["scenario_generation"] == "default") {
 				const config &generator_cfg = i.child("generator");
 				if (generator_cfg) {
 					map_generators.push_back(