Merge pull request #6850 from mattsc/mp_map_errors

MP Create Game dialog: improve error handling

src/game_initialization/create_engine.cpp

@@ -72,6 +72,8 @@ void scenario::set_metadata()
 	try {
 		map_.reset(new gamemap(map_data));
 	} catch(const incorrect_map_format_error& e) {
+		// Set map content to nullptr, so that it fails can_launch_game()
+		map_.reset(nullptr);
 		data_["description"] = _("Map could not be loaded: ") + e.message;
 
 		ERR_CF << "map could not be loaded: " << e.message << '\n';
@@ -662,6 +664,8 @@ void create_engine::init_all_levels()
 			try {
 				map.reset(new gamemap(user_map_data["map_data"]));
 			} catch (const incorrect_map_format_error& e) {
+				// Set map content to nullptr, so that it fails can_launch_game()
+				map.reset(nullptr);
 				user_map_data["description"] = _("Map could not be loaded: ") + e.message;
 
 				ERR_CF << "map could not be loaded: " << e.message << '\n';

src/gui/dialogs/multiplayer/mp_create_game.cpp

@@ -660,7 +660,6 @@ void mp_create_game::update_details()
 	boost::replace_all(title, "\n", " " + font::unicode_em_dash + " ");
 	find_widget<styled_widget>(get_window(), "game_title", false).set_label(title);
 
-	show_description(create_engine_.current_level().description());
 
 	switch(create_engine_.current_level_type()) {
 		case level_type::type::scenario:
@@ -714,6 +713,9 @@ void mp_create_game::update_details()
 			break;
 		}
 	}
+
+	// This needs to be at the end, since errors found expanding the map data are put into the description
+	show_description(create_engine_.current_level().description());
 }
 
 void mp_create_game::update_map_settings()

src/terrain/translation.cpp

@@ -709,9 +709,10 @@ static ter_layer string_to_layer_(std::string_view str)
 		return NO_LAYER;
 	}
 
-	// Validate the string
-	VALIDATE(str.size() <= 4, _("A terrain with a string with more "
-		"than 4 characters has been found, the affected terrain is:") + std::string(str));
+	if(str.size() > 4) {
+		throw error("A terrain with a string with more "
+			"than 4 characters has been found, the affected terrain is: " + std::string(str));
+	}
 
 	ter_layer result = 0;
 	// The conversion to int puts the first char