+ changed the behavior of GetCurrentBetaName() to comply with the docs, might break stuff

+ allow customizing the behavior via is_beta_branch.txt + force_branch_name.txt config files

dll/settings.h

@@ -211,6 +211,10 @@ public:
     bool assume_any_app_installed = true;
     bool appIsInstalled(AppId_t appID);
 
+    //is playing on beta branch + current/forced branch name
+    bool is_beta_branch = false;
+    std::string current_branch_name = "public";
+
     //controller
     struct Controller_Settings controller_settings;
     std::string glyphs_directory;

dll/settings_parser.cpp

@@ -461,6 +461,7 @@ uint32 create_localstorage_settings(Settings **settings_client_out, Settings **s
     bool disable_source_query = false;
     bool disable_account_avatar = false;
     bool achievement_bypass = false;
+    bool is_beta_branch = false;
     int build_id = 10;
 
     bool warn_forced = false;
@@ -495,6 +496,8 @@ uint32 create_localstorage_settings(Settings **settings_client_out, Settings **s
                 disable_account_avatar = true;
             } else if (p == "achievements_bypass.txt") {
                 achievement_bypass = true;
+            } else if (p == "is_beta_branch.txt") {
+                is_beta_branch = true;
             } else if (p == "force_language.txt") {
                 int len = Local_Storage::get_file_data(steam_settings_path + "force_language.txt", language, sizeof(language) - 1);
                 if (len > 0) {
@@ -567,6 +570,8 @@ uint32 create_localstorage_settings(Settings **settings_client_out, Settings **s
     settings_server->http_online = steamhttp_online_mode;
     settings_client->achievement_bypass = achievement_bypass;
     settings_server->achievement_bypass = achievement_bypass;
+    settings_client->is_beta_branch = is_beta_branch;
+    settings_server->is_beta_branch = is_beta_branch;
 
     if (local_save) {
         settings_client->local_save = save_path;
@@ -836,6 +841,29 @@ uint32 create_localstorage_settings(Settings **settings_client_out, Settings **s
         }
     }
 
+    {
+        std::string installed_apps_list_path = Local_Storage::get_game_settings_path() + "force_branch_name.txt";
+        std::ifstream input( utf8_decode(installed_apps_list_path) );
+        if (input.is_open()) {
+            consume_bom(input);
+            std::string line;
+            getline( input, line );
+            
+            constexpr const char * const whitespaces = " \t\r\n";
+            size_t start = line.find_first_not_of(whitespaces);
+            size_t end = line.find_last_not_of(whitespaces);
+            line = start == end
+                ? std::string()
+                : line.substr(start, end - start + 1);
+            
+            if (!line.empty()) {
+                settings_client->current_branch_name = line;
+                settings_server->current_branch_name = line;
+                PRINT_DEBUG("Forcing current branch name to '%s'\n", line.c_str());
+            }
+        }
+    }
+
     load_subscribed_groups_clans(local_storage->get_global_settings_path() + "subscribed_groups_clans.txt", settings_client, settings_server);
     load_subscribed_groups_clans(Local_Storage::get_game_settings_path() + "subscribed_groups_clans.txt", settings_client, settings_server);
 

dll/steam_apps.cpp

@@ -170,17 +170,17 @@ void Steam_Apps::RequestAppProofOfPurchaseKey( AppId_t nAppID )
 }
 
 // returns current beta branch name, 'public' is the default branch
+// "true if the user is on a beta branch; otherwise, false"
+// https://partner.steamgames.com/doc/api/ISteamApps
 bool Steam_Apps::GetCurrentBetaName( char *pchName, int cchNameBufferSize )
 {
     PRINT_DEBUG("GetCurrentBetaName %i\n", cchNameBufferSize);
-    if (!pchName) return false;
 
-    if (sizeof("public") > cchNameBufferSize) {
-        return false;
+    if (pchName && cchNameBufferSize > settings->current_branch_name.size()) {
+        memcpy(pchName, settings->current_branch_name.c_str(), settings->current_branch_name.size());
     }
 
-    memcpy(pchName, "public", sizeof("public"));
-    return true;
+    return settings->is_beta_branch;
 }
 
 // signal Steam that game files seems corrupt or missing

files_example/steam_settings.EXAMPLE/force_branch_name.EXAMPLE.txt

@@ -0,0 +1,2 @@
+rename to: force_branch_name.txt and put the name of the branch on a single line that you wish to report to the game.
+by default this is "public", you might want to look at is_beta_branch.EXAMPLE.txt

files_example/steam_settings.EXAMPLE/is_beta_branch.EXAMPLE.txt

@@ -0,0 +1 @@
+rename to: is_beta_branch.txt to tell the game that we're playing on a beta branch.