Merge branch 'master' into jgrpp

# Conflicts:
#	os/macosx/notarize.sh
#	src/3rdparty/CMakeLists.txt
#	src/3rdparty/squirrel/squirrel/sqcompiler.cpp
#	src/3rdparty/squirrel/squirrel/sqdebug.cpp
#	src/3rdparty/squirrel/squirrel/sqvm.cpp
#	src/console_cmds.cpp
#	src/core/span_type.hpp
#	src/crashlog.cpp
#	src/currency.h
#	src/date_gui.cpp
#	src/driver.cpp
#	src/fios.cpp
#	src/genworld_gui.cpp
#	src/hotkeys.cpp
#	src/misc_gui.cpp
#	src/music/os2_m.cpp
#	src/network/core/os_abstraction.h
#	src/network/network_server.cpp
#	src/newgrf.cpp
#	src/newgrf_config.h
#	src/newgrf_text.cpp
#	src/openttd.cpp
#	src/os/macosx/font_osx.cpp
#	src/os/macosx/misc_osx.cpp
#	src/os/os2/CMakeLists.txt
#	src/os/os2/os2.cpp
#	src/os/unix/CMakeLists.txt
#	src/os/windows/font_win32.cpp
#	src/os/windows/win32_main.cpp
#	src/saveload/saveload.cpp
#	src/script/api/script_text.cpp
#	src/settings.cpp
#	src/settings_gui.cpp
#	src/stdafx.h
#	src/strings.cpp
#	src/timetable_gui.cpp
#	src/town_gui.cpp
#	src/train_cmd.cpp
#	src/video/dedicated_v.cpp
#	src/video/video_driver.cpp
#	src/video/win32_v.cpp
#	src/viewport.cpp
#	src/waypoint_gui.cpp
#	src/widgets/dropdown_type.h
#	src/window.cpp
#	src/window_gui.h

src/newgrf_config.h

@@ -116,9 +116,9 @@ struct GRFError {
 
 	std::string custom_message; ///< Custom message (if present)
 	std::string data;           ///< Additional data for message and custom_message
-	StringID message;           ///< Default message
-	StringID severity;          ///< Info / Warning / Error / Fatal
-	std::array<uint32_t, 4> param_value; ///< Values of GRF parameters to show for message and custom_message
+	StringID message{};         ///< Default message
+	StringID severity{};        ///< Info / Warning / Error / Fatal
+	std::array<uint32_t, 4> param_value{}; ///< Values of GRF parameters to show for message and custom_message
 };
 
 /** The possible types of a newgrf parameter. */
@@ -163,7 +163,7 @@ struct GRFConfig : ZeroedMemoryAllocator {
 	GRFTextWrapper name;                        ///< NOSAVE: GRF name (Action 0x08)
 	GRFTextWrapper info;                        ///< NOSAVE: GRF info (author, copyright, ...) (Action 0x08)
 	GRFTextWrapper url;                         ///< NOSAVE: URL belonging to this GRF.
-	std::unique_ptr<GRFError> error;            ///< NOSAVE: Error/Warning during GRF loading (Action 0x0B)
+	std::optional<GRFError> error;              ///< NOSAVE: Error/Warning during GRF loading (Action 0x0B)
 
 	uint32 version;                             ///< NOSAVE: Version a NewGRF can set so only the newest NewGRF is shown
 	uint32 min_loadable_version;                ///< NOSAVE: Minimum compatible version a NewGRF can define