Prefer C++ in case of conflict and pass title rather than internal name

.gitignore

@@ -68,6 +68,8 @@ AppDir
 /sounds
 /mods/*
 !/mods/mods_here.txt
+/mapgens/*
+!/mapgens/mapgens_here.txt
 /worlds/*
 !/worlds/worlds_here.txt
 /clientmods/*

builtin/mainmenu/dlg_create_world.lua

@@ -79,11 +79,22 @@ local mgv6_biomes = {
 }
 
 local function create_world_formspec(dialogdata)
-
 	local current_mapgen = dialogdata.mg
 	local mapgens = core.get_mapgen_names()
-	local lua_mapgens = core.get_lua_mapgen_descriptions()
+
+	-- This is used to make sure that the internal mapgens are never overwritten by an ill-playing mapgen
+	local is_internal_mapgen = false
+	for _, mg in pairs(mapgens) do
+		if mg == current_mapgen then
+			is_internal_mapgen = true
+		end
+	end
+
+	local lua_mapgens = core.get_lua_mapgen_descriptions_and_title()
 	for k, v in pairs(lua_mapgens) do
+		if not is_internal_mapgen and v.title == dialogdata.mg then
+			current_mapgen = k
+		end
 		mapgens[#mapgens+1] = k
 	end
 
@@ -145,7 +156,13 @@ local function create_world_formspec(dialogdata)
 				selindex = i
 			end
 			i = i + 1
-			mglist = mglist .. core.formspec_escape(v) .. ","
+
+			local mapgen_title = (lua_mapgens[v] or {}).title
+			if not mapgen_title then
+				mapgen_title = v
+			end
+
+			mglist = mglist .. core.formspec_escape(mapgen_title) .. ","
 		end
 		if not selindex then
 			selindex = 1
@@ -155,9 +172,13 @@ local function create_world_formspec(dialogdata)
 	end
 
 	local current_mapgen_internal = current_mapgen
-	if lua_mapgens[current_mapgen_internal] and current_mapgen == dialogdata.mg then
+	if not is_internal_mapgen then
+		-- Select singlenode if using lua-defined mapgen
+		-- Here we have to make sure it doesn't override an internal mapgen
+		if lua_mapgens[current_mapgen_internal] ~= nil and (current_mapgen == dialogdata.mg or lua_mapgens[current_mapgen_internal].title == dialogdata.mg) then
 			current_mapgen_internal = "singlenode"
 		end
+	end
 
 	-- The logic of the flag element IDs is as follows:
 	-- "flag_main_foo-bar-baz" controls dialogdata.flags["main"]["foo_bar_baz"]
@@ -382,10 +403,24 @@ local function create_world_buttonhandler(this, fields)
 			local mapgen_internal = this.data.mg
 			local mapgen = nil
 
-			local lua_mapgens = core.get_lua_mapgen_descriptions()
-			if lua_mapgens[this.data.mg] then
+			-- This is used to make sure that the internal mapgens are never overwritten by an ill-playing mapgen
+			local internal_mapgens = core.get_mapgen_names()
+			local is_internal_mapgen = false
+			for _, mg in pairs(internal_mapgens) do
+				if mg == this.data.mg then
+					is_internal_mapgen = true
+				end
+			end
+
+			if not is_internal_mapgen then
+				local lua_mapgens = core.get_lua_mapgen_descriptions_and_title()
+				for name, v in pairs(lua_mapgens) do
+					if v.title == this.data.mg or (v.title == nil and name == this.data.mg) then
 						mapgen_internal = "singlenode"
-				mapgen = this.data.mg
+						mapgen = name
+						break
+					end
+				end
 			end
 
 			-- actual names as used by engine

doc/lua_api.md

@@ -421,6 +421,7 @@ Mapgen directory structure
     ├── mapgenname
     │   ├── mapgen.conf
     │   ├── init.lua
+    │   ├── locale/
     │   └── <custom data and code>
     └── another
 

doc/menu_lua_api.md

@@ -109,8 +109,8 @@ of manually putting one, as different OSs use different delimiters. E.g.
 * `handle:stop()` or `core.sound_stop(handle)`
 * `core.get_mapgen_names([include_hidden=false])` -> table of map generator algorithms
     registered in the core (possible in async calls)
-* `core.get_lua_mapgen_descriptions()` -> map of `[mapgen_name] = mapgen_description` as listed
-    in `mapgen.conf`.
+* `core.get_lua_mapgen_descriptions_and_title()` -> map of `[mapgen_name] = {desc = <mapgen_description>, title = <title>}` as listed
+    in `mapgen.conf`, and `nil` if they don't exist.
 * `core.get_cache_path()` -> path of cache
 * `core.get_temp_path([param])` (possible in async calls)
   * `param`=true: returns path to a newly created temporary file

src/content/mods.cpp

@@ -88,6 +88,9 @@ bool parseModContents(ModSpec &spec)
 	else
 		spec.deprecation_msgs.push_back("Mods not having a mod.conf file with the name is deprecated.");
 
+	if (info.exists("title"))
+		spec.title = info.get("title");
+
 	if (info.exists("author"))
 		spec.author = info.get("author");
 

src/content/mods.h

@@ -27,6 +27,7 @@ struct ModSpec
 	std::string author;
 	std::string path; // absolute path on disk
 	std::string desc;
+	std::string title;
 	int release = 0;
 
 	// if normal mod:

src/script/lua_api/l_mainmenu.cpp

@@ -664,18 +664,49 @@ int ModApiMainMenu::l_get_mapgen_names(lua_State *L)
 }
 
 /******************************************************************************/
-int ModApiMainMenu::l_get_lua_mapgen_descriptions(lua_State *L)
+int ModApiMainMenu::l_get_lua_mapgen_descriptions_and_title(lua_State *L)
 {
-	std::vector<ModSpec> addon_mods_in_path = flattenMods(getModsInPath(porting::path_share + DIR_DELIM + "mapgens" + DIR_DELIM, "mapgen/"));
+	std::vector<ModSpec> mapgens_in_path = flattenMods(getModsInPath(porting::path_share + DIR_DELIM + "mapgens" + DIR_DELIM, "mapgen/"));
 
 	lua_newtable(L);
-	for (const auto &mod : addon_mods_in_path) {
+	int top = lua_gettop(L);
+
+	// If more than one mapgen use the same title.
+	std::map<std::string, int> mapgen_title_counts;
+
+	for (const auto &mod : mapgens_in_path) {
 		if (mod.is_mapgen) {
+			lua_pushstring(L, mod.name.c_str());
+
+			lua_newtable(L);
+			int top_lvl2 = lua_gettop(L);
+
+			lua_pushstring(L, "desc");
+			if (mod.title != "")
 				lua_pushstring(L, mod.desc.c_str());
-			lua_setfield(L, -2, mod.name.c_str());
-		}
+			else
+				lua_pushnil(L);			
+			lua_settable(L, top_lvl2);
+
+			lua_pushstring(L, "title");
+			if (mod.title != "") {
+				std::string mapgen_tite = mod.title;
+				if (mapgen_title_counts.find(mod.title) == mapgen_title_counts.end()) {
+					mapgen_title_counts[mod.title] = 0;
+				} else {
+					mapgen_title_counts[mod.title]++;
+					mapgen_tite = mapgen_tite + " (" + mod.name + ")";
 				}
 
+				lua_pushstring(L, mapgen_tite.c_str());
+			} else {
+				lua_pushnil(L);
+			}
+			lua_settable(L, top_lvl2);
+
+			lua_settable(L, top);
+		}
+	}
 	return 1;
 }
 
@@ -1077,7 +1108,7 @@ void ModApiMainMenu::Initialize(lua_State *L, int top)
 	API_FCT(set_background);
 	API_FCT(set_topleft_text);
 	API_FCT(get_mapgen_names);
-	API_FCT(get_lua_mapgen_descriptions);
+	API_FCT(get_lua_mapgen_descriptions_and_title);
 	API_FCT(get_user_path);
 	API_FCT(get_modpath);
 	API_FCT(get_modpaths);
@@ -1119,7 +1150,7 @@ void ModApiMainMenu::InitializeAsync(lua_State *L, int top)
 	API_FCT(get_worlds);
 	API_FCT(get_games);
 	API_FCT(get_mapgen_names);
-	API_FCT(get_lua_mapgen_descriptions);
+	API_FCT(get_lua_mapgen_descriptions_and_title);
 	API_FCT(get_user_path);
 	API_FCT(get_modpath);
 	API_FCT(get_modpaths);

src/script/lua_api/l_mainmenu.h

@@ -51,7 +51,7 @@ private:
 
 	static int l_get_mapgen_names(lua_State *L);
 
-	static int l_get_lua_mapgen_descriptions(lua_State *L);
+	static int l_get_lua_mapgen_descriptions_and_title(lua_State *L);
 
 	static int l_get_language(lua_State *L);