Common mods support

Implement "common mods", includeable from
  {$user,$share}/games/common/$modname
by using the game.conf setting
  common_mods = $modname,$modname2,...

src/mods.cpp

@@ -23,6 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "subgame.h"
 #include "settings.h"
+#include "strfnd.h"
 
 std::map<std::string, ModSpec> getModsInPath(std::string path)
 {
@@ -188,11 +189,58 @@ void ModConfiguration::addMods(std::vector<ModSpec> new_mods)
 	}
 }
 
+// If failed, returned modspec has name==""
+static ModSpec findCommonMod(const std::string &modname)
+{
+	// Try to find in {$user,$share}/games/common/$modname
+	std::vector<std::string> find_paths;
+	find_paths.push_back(porting::path_user + DIR_DELIM + "games" +
+			DIR_DELIM + "common" + DIR_DELIM + "mods" + DIR_DELIM + modname);
+	find_paths.push_back(porting::path_share + DIR_DELIM + "games" +
+			DIR_DELIM + "common" + DIR_DELIM + "mods" + DIR_DELIM + modname);
+	for(u32 i=0; i<find_paths.size(); i++){
+		const std::string &try_path = find_paths[i];
+		if(fs::PathExists(try_path))
+			return ModSpec(modname, try_path);
+	}
+	// Failed to find mod
+	return ModSpec();
+}
+
 ModConfiguration::ModConfiguration(std::string worldpath)
 {
+	SubgameSpec gamespec = findWorldSubgame(worldpath);
+
+	// Add common mods without dependency handling
+	std::vector<std::string> inexistent_common_mods;
+	Settings gameconf;
+	if(getGameConfig(gamespec.path, gameconf)){
+		if(gameconf.exists("common_mods")){
+			Strfnd f(gameconf.get("common_mods"));
+			while(!f.atend()){
+				std::string modname = trim(f.next(","));
+				if(modname.empty())
+					continue;
+				ModSpec spec = findCommonMod(modname);
+				if(spec.name.empty())
+					inexistent_common_mods.push_back(modname);
+				else
+					m_sorted_mods.push_back(spec);
+			}
+		}
+	}
+	if(!inexistent_common_mods.empty()){
+		std::string s = "Required common mods ";
+		for(u32 i=0; i<inexistent_common_mods.size(); i++){
+			if(i != 0) s += ", ";
+			s += std::string("\"") + inexistent_common_mods[i] + "\"";
+		}
+		s += " could not be found.";
+		throw ModError(s);
+	}
+
 	// Add all world mods and all game mods
 	addModsInPath(worldpath + DIR_DELIM + "worldmods");
-	SubgameSpec gamespec = findWorldSubgame(worldpath);
 	addModsInPath(gamespec.gamemods_path);
 
 	// check world.mt file for mods explicitely declared to be

src/subgame.cpp

@@ -24,12 +24,16 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "util/string.h"
 
-std::string getGameName(const std::string &game_path)
+bool getGameConfig(const std::string &game_path, Settings &conf)
 {
 	std::string conf_path = game_path + DIR_DELIM + "game.conf";
+	return conf.readConfigFile(conf_path.c_str());
+}
+
+std::string getGameName(const std::string &game_path)
+{
 	Settings conf;
-	bool succeeded = conf.readConfigFile(conf_path.c_str());
-	if(!succeeded)
+	if(!getGameConfig(game_path, conf))
 		return "";
 	if(!conf.exists("name"))
 		return "";
@@ -117,6 +121,11 @@ std::set<std::string> getAvailableGameIds()
 		for(u32 j=0; j<dirlist.size(); j++){
 			if(!dirlist[j].dir)
 				continue;
+			// If configuration file is not found or broken, ignore game
+			Settings conf;
+			if(!getGameConfig(*i + DIR_DELIM + dirlist[j].name, conf))
+				continue;
+			// Add it to result
 			const char *ends[] = {"_game", NULL};
 			std::string shorter = removeStringEnd(dirlist[j].name, ends);
 			if(shorter != "")

src/subgame.h

@@ -24,6 +24,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <set>
 #include <vector>
 
+class Settings;
+
 #define WORLDNAME_BLACKLISTED_CHARS "/\\"
 
 struct SubgameSpec
@@ -52,6 +54,8 @@ struct SubgameSpec
 	}
 };
 
+bool getGameConfig(const std::string &game_path, Settings &conf);
+
 std::string getGameName(const std::string &game_path);
 
 SubgameSpec findSubgame(const std::string &id);