Merge branch 'master' into jgrpp

# Conflicts:
#	src/aircraft_cmd.cpp
#	src/autoreplace_cmd.cpp
#	src/pathfinder/follow_track.hpp
#	src/pathfinder/yapf/yapf_rail.cpp
#	src/saveload/afterload.cpp
#	src/saveload/saveload.cpp
#	src/script/api/ai/ai_station.hpp.sq
#	src/script/api/game/game_station.hpp.sq
#	src/script/api/script_station.hpp
#	src/track_func.h
#	src/vehicle_base.h

src/core/bitmath_func.hpp

@@ -330,6 +330,7 @@ static inline bool HasAtMostOneBit(T value)
 template <typename T>
 static inline T ROL(const T x, const uint8 n)
 {
+	if (n == 0) return x;
 	return (T)(x << n | x >> (sizeof(x) * 8 - n));
 }
 
@@ -345,6 +346,7 @@ static inline T ROL(const T x, const uint8 n)
 template <typename T>
 static inline T ROR(const T x, const uint8 n)
 {
+	if (n == 0) return x;
 	return (T)(x >> n | x << (sizeof(x) * 8 - n));
 }