--no-update-check argumment added and backend for update checking added

doc/man/wesnoth.6

@@ -204,6 +204,9 @@ don't try to validate replay of unit test. Only relevant when used with
 .B --nosound
 runs the game without sounds and music.
 .TP
+.B --no-update-check
+runs the game without checking for updates. (Available only on macOS and Windows)
+.TP
 .BI --password \ password
 uses
 .I password

src/commandline_options.cpp

@@ -105,6 +105,11 @@ commandline_options::commandline_options (const std::vector<std::string>& args)
 	nogui(false),
 	nomusic(false),
 	nosound(false),
+#if defined(__linux__)
+	noupdatecheck(true),
+#else
+	noupdatecheck(false),
+#endif
 	new_widgets(false),
 	path(false),
 	preprocess(false),
@@ -173,6 +178,9 @@ commandline_options::commandline_options (const std::vector<std::string>& args)
 		("nodelay", "runs the game without any delays.")
 		("nomusic", "runs the game without music.")
 		("nosound", "runs the game without sounds and music.")
+#if !defined(__linux__)
+		("no-update-check", "runs the game without automatic checking for update.")
+#endif
 		("password", po::value<std::string>(), "uses <password> when connecting to a server, ignoring other preferences.")
 		("path", "prints the path to the data directory and exits.")
 		("plugin", po::value<std::string>(), "(experimental) load a script which defines a wesnoth plugin. similar to --script below, but lua file should return a function which will be run as a coroutine and periodically woken up with updates.")
@@ -400,6 +408,8 @@ commandline_options::commandline_options (const std::vector<std::string>& args)
 		noreplaycheck = true;
 	if (vm.count("nosound"))
 		nosound = true;
+	if (vm.count("no-update-check"))
+		noupdatecheck = true;
 	if (vm.count("nogui"))
 		nogui = true;
 	if (vm.count("parm"))

src/commandline_options.hpp

@@ -139,6 +139,8 @@ friend std::ostream& operator<<(std::ostream &os, const commandline_options& cmd
 	bool nomusic;
 	/// True if --nosound was given on the command line. Disables sound.
 	bool nosound;
+	/// True if --no-update-check was given on the command line. True by default on Linux. Disables automatic update checking.
+	bool noupdatecheck;
 	/// True if --new-widgets was given on the command line. Hidden option to enable the new widget toolkit.
 	bool new_widgets;
 	/// True if --path was given on the command line. Prints the path to data directory and exits.

src/game_launcher.cpp

@@ -210,6 +210,11 @@ game_launcher::game_launcher(const commandline_options& cmdline_opts, const char
 		no_music = true;
 	if (cmdline_opts_.nosound)
 		no_sound = true;
+	if (cmdline_opts_.noupdatecheck) {
+		preferences::set_update_check(false);
+	} else {
+		preferences::set_update_check(true);
+	}
 	if (cmdline_opts_.resolution) {
 		const int xres = std::get<0>(*cmdline_opts_.resolution);
 		const int yres = std::get<1>(*cmdline_opts_.resolution);

src/gui/dialogs/title_screen.cpp

@@ -238,7 +238,11 @@ void title_screen::pre_show(window& win)
 	//
 	// Version string
 	//
-	const std::string& version_string = VGETTEXT("Version $version", {{ "version", game_config::revision }});
+	std::string version_string = VGETTEXT("Version $version", {{ "version", game_config::revision }});
+
+	if (preferences::update_check()) {
+		version_string += " | " + VGETTEXT("New updated version $new_version available!", {{ "new_version", "1.14.5" }});
+	}
 
 	if(label* version_label = find_widget<label>(&win, "revision_number", false, false)) {
 		version_label->set_label(version_string);

src/preferences/general.cpp

@@ -714,6 +714,16 @@ void set_stop_music_in_background(bool ison)
 	preferences::set("stop_music_in_background", ison);
 }
 
+void set_update_check(bool ison)
+{
+	prefs["update_check"] = ison;
+}
+
+bool update_check()
+{
+	return get("update_check", false);
+}
+
 namespace {
 	double scroll = 0.2;
 }

src/preferences/general.hpp

@@ -192,6 +192,9 @@ namespace preferences {
 
 	bool use_color_cursors();
 	void _set_color_cursors(bool value);
+
+	void set_update_check(bool ison);
+	bool update_check();
 
 	bool joystick_support_enabled();
 	int joystick_mouse_deadzone();