Create savegame filenames with the same code as in actual saving

Follow-up to commit 057a530.

Otherwise, Menu -> Back to... would be broken whenever the logic differs
between that feature and actual saving.

src/hotkey/hotkey_handler.cpp

@@ -394,10 +394,14 @@ void play_controller::hotkey_handler::expand_autosaves(std::vector<config>& item
 	std::vector<config> newitems;
 	std::vector<std::string> newsaves;
 
-	const std::string& start_name = saved_game_.classification().label;
+	compression::format compression_format = preferences::save_compression_format();
+	savegame::autosave_savegame autosave(saved_game_, compression_format);
+	savegame::scenariostart_savegame scenariostart_save(saved_game_, compression_format);
+
+	const std::string start_name = scenariostart_save.create_filename();
 
 	for(unsigned int turn = play_controller_.turn(); turn != 0; turn--) {
-		const std::string name = formatter() << start_name << "-" << _("Auto-Save") << turn;
+		const std::string name = autosave.create_filename(turn);
 
 		if(savegame::save_game_exists(name, comp_format)) {
 			newsaves.emplace_back(name + compression::format_extension(comp_format));

src/savegame.cpp

@@ -337,7 +337,7 @@ savegame::savegame(saved_game& gamestate, const compression::format compress_sav
 bool savegame::save_game_automatic(bool ask_for_overwrite, const std::string& filename)
 {
 	if (filename.empty())
-		create_filename();
+		filename_ = create_filename();
 	else
 		filename_ = filename;
 
@@ -353,7 +353,7 @@ bool savegame::save_game_automatic(bool ask_for_overwrite, const std::string& fi
 bool savegame::save_game_interactive(const std::string& message, DIALOG_TYPE dialog_type)
 {
 	show_confirmation_ = true;
-	create_filename();
+	filename_ = create_filename();
 
 	const int res = show_save_dialog(message, dialog_type);
 
@@ -383,8 +383,6 @@ int savegame::show_save_dialog(const std::string& message, DIALOG_TYPE dialog_ty
 		res = dlg.get_retval();
 	}
 
-	set_filename(filename_);
-
 	if (!check_filename(filename_)) {
 		res = gui2::window::CANCEL;
 	}
@@ -425,11 +423,12 @@ bool savegame::is_illegal_file_char(char c)
 	;
 }
 
-void savegame::set_filename(std::string filename)
+std::string savegame::create_filename(unsigned int turn_number) const
 {
+	std::string filename = create_initial_filename(turn_number);
 	filename.erase(std::remove_if(filename.begin(), filename.end(),
 	            is_illegal_file_char), filename.end());
-	filename_ = filename;
+	return filename;
 }
 
 void savegame::before_save()
@@ -541,7 +540,12 @@ filesystem::scoped_ostream savegame::open_save_game(const std::string &label)
 scenariostart_savegame::scenariostart_savegame(saved_game &gamestate, const compression::format compress_saves)
 	: savegame(gamestate, compress_saves)
 {
-	set_filename(gamestate.classification().label);
+	filename_ = create_filename();
+}
+
+std::string scenariostart_savegame::create_initial_filename(unsigned int) const
+{
+	return gamestate().classification().label;
 }
 
 void scenariostart_savegame::write_game(config_writer &out){
@@ -553,9 +557,9 @@ replay_savegame::replay_savegame(saved_game &gamestate, const compression::forma
 	: savegame(gamestate, compress_saves, _("Save Replay"))
 {}
 
-void replay_savegame::create_filename()
+std::string replay_savegame::create_initial_filename(unsigned int) const
 {
-	set_filename(formatter() << gamestate().classification().label << " " << _("replay"));
+	return formatter() << gamestate().classification().label << " " << _("replay");
 }
 
 void replay_savegame::write_game(config_writer &out) {
@@ -586,15 +590,15 @@ void autosave_savegame::autosave(const bool disable_autosave, const int autosave
 	remove_old_auto_saves(autosave_max, infinite_autosaves);
 }
 
-void autosave_savegame::create_filename()
+std::string autosave_savegame::create_initial_filename(unsigned int turn_number) const
 {
 	std::string filename;
-	if (gamestate().classification().label.empty())
+	if(gamestate().classification().label.empty())
 		filename = _("Auto-Save");
 	else
-		filename = gamestate().classification().label + "-" + _("Auto-Save") + gamestate().get_starting_pos()["turn_at"];
+		filename = gamestate().classification().label + "-" + _("Auto-Save") + std::to_string(turn_number);
 
-	set_filename(filename);
+	return filename;
 }
 
 oos_savegame::oos_savegame(saved_game& gamestate, bool& ignore)
@@ -606,17 +610,13 @@ int oos_savegame::show_save_dialog(const std::string& message, DIALOG_TYPE /*dia
 {
 	int res = 0;
 
-	std::string filename = this->filename();
-
 	if (!ignore_){
-		gui2::dialogs::game_save_oos dlg(ignore_, filename, title(), message);
+		gui2::dialogs::game_save_oos dlg(ignore_, filename_, title(), message);
 		dlg.show();
 		res = dlg.get_retval();
 	}
 
-	set_filename(filename);
-
-	if (!check_filename(filename)) {
+	if (!check_filename(filename_)) {
 		res = gui2::window::CANCEL;
 	}
 
@@ -628,10 +628,10 @@ ingame_savegame::ingame_savegame(saved_game &gamestate, const compression::forma
 {
 }
 
-void ingame_savegame::create_filename()
+std::string ingame_savegame::create_initial_filename(unsigned int turn_number) const
 {
-	set_filename(formatter() << gamestate().classification().label
-		<< " " << _("Turn") << " " << gamestate().get_starting_pos()["turn_at"]);
+	return formatter() << gamestate().classification().label
+		<< " " << _("Turn") << " " << turn_number;
 }
 
 void ingame_savegame::write_game(config_writer &out) {

src/savegame.hpp

@@ -18,12 +18,12 @@
 #include "config.hpp"
 #include "filesystem.hpp"
 #include "lua_jailbreak_exception.hpp"
+#include "saved_game.hpp"
 #include "serialization/compression.hpp"
 
 #include <exception>
 
 class config_writer;
-class saved_game;
 class version_info;
 
 namespace savegame {
@@ -170,16 +170,22 @@ class savegame
 
 	const std::string& filename() const { return filename_; }
 
+	/** Build the filename according to the specific savegame's needs. */
+	std::string create_filename() const
+	{
+		return create_filename(gamestate().get_starting_pos()["turn_at"]);
+	}
+
+	/** Build the filename for the specified turn. */
+	std::string create_filename(unsigned int turn_number) const;
+
 protected:
 	/**
 		Save a game without any further user interaction.
 		The return value denotes, if the save was successful or not.
 	*/
 	bool save_game(const std::string& filename = "");
 
-	/** Sets the filename and removes invalid characters. Don't set the filename directly but
-		use this method instead. */
-	void set_filename(std::string filename);
 	/** Check, if the filename contains illegal constructs like ".gz". */
 	bool check_filename(const std::string& filename);
 
@@ -195,13 +201,15 @@ class savegame
 	/** Writing the savegame config to a file. */
 	virtual void write_game(config_writer &out);
 
+	/** Filename of the savegame file on disk */
+	std::string filename_;
+
 private:
 	/** Checks if a certain character is allowed in a savefile name. */
 	static bool is_illegal_file_char(char c);
 
-	/** Build the filename according to the specific savegame's needs. Subclasses will have to
-		override this to take effect. */
-	virtual void create_filename() {}
+	/** Subclass-specific part of filename building. */
+	virtual std::string create_initial_filename(unsigned int turn_number) const = 0;
 	/** Display the save game dialog. */
 	virtual int show_save_dialog(const std::string& message, DIALOG_TYPE dialog_type);
 	/** Ask the user if an existing file should be overwritten. */
@@ -218,8 +226,6 @@ class savegame
 	friend class save_info;
 	//before_save (write replay data) changes this so it cannot be const
 	saved_game& gamestate_;
-	/** Filename of the savegame file on disk */
-	std::string filename_;
 
 	const std::string title_; /** Title of the savegame dialog */
 
@@ -239,7 +245,7 @@ class ingame_savegame : public savegame
 
 private:
 	/** Create a filename for automatic saves */
-	virtual void create_filename() override;
+	virtual std::string create_initial_filename(unsigned int turn_number) const override;
 
 
 	void write_game(config_writer &out) override;
@@ -253,7 +259,7 @@ class replay_savegame : public savegame
 
 private:
 	/** Create a filename for automatic saves */
-	virtual void create_filename() override;
+	virtual std::string create_initial_filename(unsigned int turn_number) const override;
 
 	void write_game(config_writer &out) override;
 };
@@ -267,7 +273,7 @@ class autosave_savegame : public ingame_savegame
 	void autosave(const bool disable_autosave, const int autosave_max, const int infinite_autosaves);
 private:
 	/** Create a filename for automatic saves */
-	virtual void create_filename() override;
+	virtual std::string create_initial_filename(unsigned int turn_number) const override;
 };
 
 class oos_savegame : public ingame_savegame
@@ -288,6 +294,9 @@ class scenariostart_savegame : public savegame
 	scenariostart_savegame(saved_game& gamestate, const compression::format compress_saves);
 
 private:
+	/** Create a filename for automatic saves */
+	virtual std::string create_initial_filename(unsigned int turn_number) const override;
+
 	void write_game(config_writer &out) override;
 };