Also, the man page says:
Prior to Linux 1.1.38, the saved ID paradigm, when used
with setregid or setegid was broken. Starting at 1.1.38,
it is also possible to set the effective group ID from the
saved user ID.
--
Pixar Animation Studios: Reality is not our business.
Pixar's "Toy Story" $184,849,036 domestic, $117.5M overseas and counting.
That makes it number 21 in box office figures of all films ever released.