Clean up some Cppcheck warnings by passing args as const refs (#4364)

src/addon/validation.cpp

@@ -168,7 +168,7 @@ bool check_names_legal_internal(const config& dir, std::string current_prefix, s
 	return badlist ? badlist->empty() : true;
 }
 
-bool check_case_insensitive_duplicates_internal(const config& dir, std::string prefix, std::vector<std::string>* badlist){
+bool check_case_insensitive_duplicates_internal(const config& dir, const std::string& prefix, std::vector<std::string>* badlist){
 	typedef std::pair<bool, std::string> printed_and_original;
 	std::map<std::string, printed_and_original> filenames;
 	bool inserted;

src/attack_prediction.cpp

@@ -1408,8 +1408,8 @@ public:
 			unsigned int rounds,
 			double a_hit_chance,
 			double b_hit_chance,
-			std::vector<combat_slice> a_split,
-			std::vector<combat_slice> b_split,
+			const std::vector<combat_slice>& a_split,
+			const std::vector<combat_slice>& b_split,
 			double a_initially_slowed_chance,
 			double b_initially_slowed_chance);
 
@@ -1464,8 +1464,8 @@ monte_carlo_combat_matrix::monte_carlo_combat_matrix(unsigned int a_max_hp,
 		unsigned int rounds,
 		double a_hit_chance,
 		double b_hit_chance,
-		std::vector<combat_slice> a_split,
-		std::vector<combat_slice> b_split,
+		const std::vector<combat_slice>& a_split,
+		const std::vector<combat_slice>& b_split,
 		double a_initially_slowed_chance,
 		double b_initially_slowed_chance)
 	: combat_matrix(a_max_hp,

src/desktop/dbus_features.cpp

@@ -46,7 +46,7 @@ bool kde_style = false;
 
 struct wnotify
 {
-	wnotify(uint32_t id_arg, std::string owner_arg, std::string message_arg)
+	wnotify(uint32_t id_arg, const std::string & owner_arg, const std::string & message_arg)
 		: id(id_arg)
 		, owner(owner_arg)
 		, message(message_arg)

src/display.cpp

@@ -920,7 +920,7 @@ void display::render_buttons()
 }
 
 
-gui::button::TYPE display::string_to_button_type(std::string type)
+gui::button::TYPE display::string_to_button_type(const std::string& type)
 {
 	gui::button::TYPE res = gui::button::TYPE_PRESS;
 	if (type == "checkbox") { res = gui::button::TYPE_CHECK; }

src/display.hpp

@@ -392,7 +392,7 @@ public:
 	std::shared_ptr<gui::button> find_action_button(const std::string& id);
 	std::shared_ptr<gui::button> find_menu_button(const std::string& id);
 
-	static gui::button::TYPE string_to_button_type(std::string type);
+	static gui::button::TYPE string_to_button_type(const std::string& type);
 	void create_buttons();
 
 	void layout_buttons();

src/game_initialization/configure_engine.hpp

@@ -140,12 +140,12 @@ public:
 	// Setter methods
 	//
 
-	void set_game_name(std::string name)
+	void set_game_name(const std::string& name)
 	{
 		parameters_.name = name;
 	}
 
-	void set_game_password(std::string name)
+	void set_game_password(const std::string& name)
 	{
 		parameters_.password = name;
 	}

src/game_initialization/lobby_data.cpp

@@ -184,7 +184,7 @@ std::string make_short_name(const std::string& long_name)
 	return ss.str();
 }
 
-std::string make_game_type_marker(std::string text, bool color_for_missing)
+std::string make_game_type_marker(const std::string& text, bool color_for_missing)
 {
 	if(color_for_missing) {
 		return formatter() << "<b><span color='#f00'>[" << text << "]</span></b> ";

src/game_launcher.hpp

@@ -82,7 +82,7 @@ public:
 
 	bool jump_to_editor() const { return jump_to_editor_; }
 
-	void select_mp_server(std::string server) { multiplayer_server_ = server; }
+	void select_mp_server(const std::string& server) { multiplayer_server_ = server; }
 	bool play_multiplayer(mp_selection res);
 	bool play_multiplayer_commandline();
 	bool change_language();

src/gui/dialogs/unit_list.cpp

@@ -67,7 +67,7 @@ static std::string format_level_string(const int level)
 
 }
 
-static std::string format_if_leader(unit_const_ptr u, const std::string str)
+static std::string format_if_leader(unit_const_ptr u, const std::string& str)
 {
 	return (*u).can_recruit() ? "<span color='#cdad00'>" + str + "</span>" : str;
 }

src/hotkey/hotkey_item.hpp

@@ -251,7 +251,7 @@ public:
 		keycode_ = keycode;
 	}
 
-	void set_text(std::string text)
+	void set_text(const std::string& text)
 	{
 		text_ = text;
 		boost::algorithm::to_lower(text_);

src/map_command_handler.hpp

@@ -128,8 +128,8 @@ public:
 		std::string help; //long help text
 		std::string usage; //only args info
 		std::string flags;
-		explicit command(command_handler h, const std::string help = "",
-			const std::string& usage = "", const std::string flags = "")
+		explicit command(command_handler h, const std::string& help = "",
+			const std::string& usage = "", const std::string& flags = "")
 			: handler(h), help(help), usage(usage), flags(flags)
 		{
 		}
@@ -354,7 +354,7 @@ protected:
 		help_on_unknown_ = value;
 	}
 	//this is display-only
-	static void set_cmd_prefix(std::string value)
+	static void set_cmd_prefix(const std::string& value)
 	{
 		cmd_prefix_ = value;
 	}

src/playturn_network_adapter.cpp

@@ -59,7 +59,7 @@ void playturn_network_adapter::read_from_network()
 	//there should be no attributes left.
 }
 
-bool playturn_network_adapter::is_at_end()
+bool playturn_network_adapter::is_at_end() const
 {
 	assert(!data_.empty());
 	if (data_.size() > 1) return false;

src/playturn_network_adapter.hpp

@@ -33,7 +33,7 @@ public:
 	//after the call dst contains one child when returned true otherwise it's empty.
 	bool read(config& dst);
 	//returns false if there is still data in the internal buffer.
-	bool is_at_end();
+	bool is_at_end() const;
 	void set_source(source_type source);
 	//returns a function to be passed to set_source.
 	static source_type get_source_from_config(config& src);

src/scripting/lua_fileops.cpp

@@ -62,7 +62,7 @@ static std::string get_calling_file(lua_State* L)
 }
 /// resolves @a filename to an absolute path
 /// @returns true if the filename was successfully resolved.
-static bool canonical_path(std::string& filename, std::string currentdir)
+static bool canonical_path(std::string& filename, const std::string& currentdir)
 {
 	if(filename.size() < 2) {
 		return false;
@@ -109,7 +109,7 @@ static bool canonical_path(std::string& filename, std::string currentdir)
 
 /// resolves @a filename to an absolute path
 /// @returns true if the filename was successfully resolved.
-static bool resolve_filename(std::string& filename, std::string currentdir, std::string* rel = nullptr)
+static bool resolve_filename(std::string& filename, const std::string& currentdir, std::string* rel = nullptr)
 {
 	if(!canonical_path(filename, currentdir)) {
 		return false;

src/tests/gui/test_gui2.cpp

@@ -971,7 +971,7 @@ struct dialog_tester<screenshot_notification>
 template<>
 struct dialog_tester<theme_list>
 {
-	static theme_info make_theme(std::string name)
+	static theme_info make_theme(const std::string& name)
 	{
 		theme_info ti;
 		ti.id = name;