Option to use a per-server-ID updates directory.

Change from fully specified path to one based on the ID from
servers.lst.  The option now just enables/disables the new path.
For example:  an ID of pk uses <config base>/updates/pk/.

elconfig.c

@@ -3157,7 +3157,7 @@ static void init_ELC_vars(void)
 		SERVER);
 	add_var(OPT_BOOL,"write_ini_on_exit", "wini", &write_ini_on_exit, change_var, 1,"Save INI","Save options when you quit",SERVER);
 	add_var(OPT_STRING,"data_dir","dir",datadir,change_dir_name,90,"Data Directory","Place were we keep our data. Can only be changed with a Client restart.",SERVER);
-	add_var(OPT_STRING,"alt_updates_dir","aupdir",alt_updates_dir,change_dir_name,90,"Alt Updates Directory","Full path to an alternative updates directory for data files.  Normally blank.",SERVER);
+	add_var(OPT_BOOL,"use_perserver_updates_dir", "uaupdir", &use_perserver_updates_dir, change_var, 0,"Use Per-Server Updates Directory","If enabled a per-server-ID updates directory is used rather than the default that uses the client version.  A change only takes effect after a client restart.",SERVER);
 #endif // ANDROID
 	add_var(OPT_BOOL,"serverpopup","spu",&use_server_pop_win,change_var,1,"Use Special Text Window","Toggles whether server messages from channel 255 are displayed in a pop up window.",SERVER);
 	/* Note: We don't take any action on the already-running thread, as that wouldn't necessarily be good. */

init.c

@@ -113,7 +113,7 @@ char datadir[256]=DATA_DIR;
 char datadir[256]="./";
 #endif //DATA_DIR
 
-char alt_updates_dir[256]="";
+int use_perserver_updates_dir = 0;
 
 static const char *cfg_filename = "el.cfg";
 #ifdef JSON_FILES

init.h

@@ -251,7 +251,7 @@ typedef struct
 
 extern char configdir[256]; /*!< the default directory where we look for configuration files */
 extern char datadir[256]; /*!< the default directory where we look for data files (aka installation dir) */
-extern char alt_updates_dir[256]; /*!< an alternative updates directory for data files, if blank, default is <config base>/updates/<version> */
+extern int use_perserver_updates_dir; /*!< by default <config base>/updates/<version> is used for updates, if true <config base>/updates/server_ID will be used */
 
 /*!
  * \ingroup loadsave

io/elpathwrapper.c

@@ -193,8 +193,8 @@ const char * get_path_updates(void)
 	}
 
 #ifndef MAP_EDITOR
-	if (alt_updates_dir[0] != '\0')
-		safe_snprintf(locbuffer, sizeof(locbuffer), "%s", alt_updates_dir);
+	if (use_perserver_updates_dir)
+		safe_snprintf(locbuffer, sizeof(locbuffer), "%supdates/%s/", get_path_config_base(), get_server_name());
 	else
 #endif
 		safe_snprintf(locbuffer, sizeof(locbuffer), "%supdates/%d_%d_%d/", get_path_config_base(), VER_MAJOR, VER_MINOR, VER_RELEASE);