read -n option doesn't work right with -u

[b_bashbug]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: i686-pc-linux-gnu-gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -O3 -pipe -march=pentium3 
-fomit-frame-pointer
uname output: Linux newbie 2.6.17-gentoo-r8 #2 SMP Mon Oct 23 23:53:40 EDT 2006 
i686 Pentium III (Coppermine) GenuineIntel GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 3.2
Patch Level: 17
Release Status: release

Description:
        read -u option does not work with -n properly.  In particular, it waits
        for a newline if fd 0 is closed.

Repeat-By:
        Consider:
            exec 3<&0
            read -n 1 -u 3
        This sequence will read a single character from stdin (the terminal)
        without waiting for a newline.  However, consider
            exec 3<&0 0<&-
            read -n 1 -u 3
        This sequence closes fd 0, and bash waits for a newline before reading
        the character.
        Note that I am working around this as follows:
            exec 3<&0 0<&-
            read -n 1 <&3
        The preceding works, presumably because it's reading from fd 0 again.

Fix:
        I would suspect that the -n option needs to pay attention to the -u
        flag, and not just assume fd 0.