give better error messages for font initialization failure

src/font/error.hpp

@@ -0,0 +1,29 @@
+/*
+   Copyright (C) 2016 by Chris Beck<render787@gmail.com>
+   Part of the Battle for Wesnoth Project http://www.wesnoth.org/
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY.
+
+   See the COPYING file for more details.
+*/
+
+#ifndef FONT_ERROR_HPP
+#define FONT_ERROR_HPP
+
+#include "exceptions.hpp"
+#include <string>
+
+namespace font {
+
+struct error : public game::error {
+	error(std::string str = "Font initialization failed") : game::error(str) {}
+};
+
+} // end namespace font
+
+#endif

src/font/font_config.cpp

@@ -14,6 +14,7 @@
 
 #include "font_config.hpp"
 #include "font_description.hpp"
+#include "font/error.hpp"
 #include "sdl_ttf.hpp"
 
 #include "config.hpp"
@@ -183,18 +184,21 @@ const t_string& get_font_families(family_class fclass)
 manager::manager()
 {
 #ifdef CAIRO_HAS_FT_FONT
+	std::string font_path = game_config::path + "/fonts";
 	if (!FcConfigAppFontAddDir(FcConfigGetCurrent(),
-		reinterpret_cast<const FcChar8 *>((game_config::path + "/fonts").c_str())))
+		reinterpret_cast<const FcChar8 *>(font_path.c_str())))
 	{
 		ERR_FT << "Could not load the true type fonts" << std::endl;
-		throw error();
+		throw font::error("font config lib failed to add the font path: '" + font_path + "'");
 	}
 
+	std::string font_file = font_path + "/fonts.conf";
 	if(!FcConfigParseAndLoad(FcConfigGetCurrent(),
-							 reinterpret_cast<const FcChar8*>((game_config::path + "/fonts/fonts.conf").c_str()),
+							 reinterpret_cast<const FcChar8*>(font_file.c_str()),
 							 FcFalse))
 	{
 		ERR_FT << "Could not load local font configuration\n";
+		throw font::error("font config lib failed to find font.conf: '" + font_file + "'");
 	}
 	else
 	{

src/font/font_config.hpp

@@ -20,7 +20,6 @@
  * sdl_ttf raii object.
  */
 
-#include "exceptions.hpp"
 #include "font_options.hpp"
 #include "sdl_ttf.hpp"
 
@@ -43,9 +42,6 @@ struct manager {
 	manager(const manager &) = delete;
 	manager & operator = (const manager &) = delete;
 
-	struct error : public game::error {
-		error() : game::error("Font initialization failed") {}
-	};
 private:
 
     /** Initialize sdl_ttf concurrent with font::manager lifetime */

src/font/sdl_ttf.cpp

@@ -14,6 +14,7 @@
 
 #include "sdl_ttf.hpp"
 
+#include "font/error.hpp"
 #include "font_config.hpp"
 #include "font_id.hpp"
 #include "text_cache.hpp"
@@ -490,7 +491,7 @@ sdl_ttf::sdl_ttf() {
 	const int res = TTF_Init();
 	if(res == -1) {
 		ERR_FT << "Could not initialize SDL_TTF" << std::endl;
-		throw manager::error();
+		throw font::error("SDL_TTF could not initialize, TTF_INIT returned: " + std::to_string(res));
 	} else {
 		LOG_FT << "Initialized true type fonts\n";
 	}

src/wesnoth.cpp

@@ -23,17 +23,18 @@
 #include "filesystem.hpp"               // for filesystem::file_exists, filesystem::io_exception, etc
 #include "floating_label.hpp"
 #include "font/font_config.hpp"         // for load_font_config, etc
-#include "formula/formula.hpp"                  // for formula_error
+#include "font/error.hpp"				// for error
+#include "formula/formula.hpp"          // for formula_error
 #include "game_config.hpp"              // for path, debug, debug_lua, etc
 #include "game_config_manager.hpp"      // for game_config_manager, etc
 #include "game_end_exceptions.hpp"
-#include "game_launcher.hpp"          // for game_launcher, etc
+#include "game_launcher.hpp"          	// for game_launcher, etc
 #include "gettext.hpp"
-#include "gui/core/event/handler.hpp"  // for tmanager
+#include "gui/core/event/handler.hpp"  	// for tmanager
 #include "gui/dialogs/end_credits.hpp"
 #include "gui/dialogs/loadscreen.hpp"
 #include "gui/dialogs/title_screen.hpp"  // for ttitle_screen, etc
-#include "gui/dialogs/message.hpp" 	// for show_error_message
+#include "gui/dialogs/message.hpp" 		// for show_error_message
 #include "gui/widgets/helper.hpp"       // for init
 #include "image.hpp"                    // for flush_cache, etc
 #include "log.hpp"                      // for LOG_STREAM, general, logger, etc
@@ -1058,7 +1059,7 @@ int main(int argc, char** argv)
 	} catch(CVideo::error & e) {
 		std::cerr << "Could not initialize video.\n\n" << e.what() << "\n\nExiting.\n";
 		error_exit(1);
-	} catch(font::manager::error & e) {
+	} catch(font::error & e) {
 		std::cerr << "Could not initialize fonts.\n\n" << e.what() << "\n\nExiting.\n";
 		error_exit(1);
 	} catch(config::error& e) {