Found by strac'ing kstartupconfig.
@ -84,7 +84,7 @@ int main()
if (getenv( "XDG_CONFIG_HOME" )) {
kdehome = getenv("XDG_CONFIG_HOME");
} else {
kdehome = "~/.config";
kdehome = std::string(getenv("HOME")) + "/.config";
}
filename = kdehome + "/startupconfig";
if (access(filename.c_str(), R_OK) != 0)