Merge branch 'master' into jgrpp

# Conflicts:
#	src/3rdparty/fmt/core.h
#	src/command_type.h
#	src/console_cmds.cpp
#	src/core/overflowsafe_type.hpp
#	src/landscape.cpp
#	src/network/network.cpp
#	src/newgrf_object.h
#	src/object_cmd.cpp
#	src/order_gui.cpp
#	src/saveload/vehicle_sl.cpp
#	src/script/api/script_industrytype.cpp
#	src/script/api/script_object.hpp
#	src/script/api/script_town.cpp
#	src/table/object_land.h
#	src/timetable_cmd.cpp
#	src/tree_cmd.cpp
#	src/vehicle_gui.cpp
#	src/window.cpp

src/script/api/script_window.cpp

@@ -46,6 +46,7 @@
 	if (colour != TC_INVALID && (::TextColour)colour >= ::TC_END) return;
 
 	Window *w = FindWindowById((::WindowClass)window, number);
+	assert(w != nullptr);
 
 	if (widget == WIDGET_ALL) {
 		if (colour != TC_INVALID) return;