[PATCH] libc_r bug: successful close(2) sets errno to ENOTTY

[boyd, rounin]

From: "Stefan Farfeleder" <stefan at fafoe.narf.at>
> > errno is meaningful for syscalls after an error (the original
> > message).  The fact that other functions also dink with errno is not
> > relevant to that statement.
> 
> I read boyd's statement as a contradiction to Jacques' one (only after
> syscall error vs. after library call error).

some libc functions do mangle errno, but only after an error.

in my terse statement the intention was to affirm that errno is
meaningless unless an error has ocurred (a syscall being the
simplest case, while random other libc calls may behave in
the same way).