printf -v variable ignores nullglob

[Elmar Stellnberger]

Configuration Information [Automatically generated, do not change]:
Machine: i586
OS: linux
Compiler: gcc -I/usr/src/packages/BUILD/bash-3.1
-L/usr/src/packages/BUILD/bash-3.1/../readline-5.1
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i586'
-DCONF_OSTYPE='linux' -DCONF_MACHTYPE='i586-suse-linux'
-DCONF_VENDOR='suse' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash'
-DSHELL -DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -O2 -march=i586
-mtune=i686 -fmessage-length=0 -Wall -D_FORTIFY_SOURCE=2 -g
-D_GNU_SOURCE -DRECYCLES_PIDS -Wall -pipe -g -fbranch-probabilities
uname output: Linux sonic 2.6.16.21-0.25-default #1 Tue Sep 19 07:26:15
UTC 2006 i686 i686 i386 GNU/Linux
Machine Type: i586-suse-linux

Bash Version: 3.1
Patch Level: 17
Release Status: release

Repeat By:
1. shopt -s nullglob extglob
2. echo "x$(printf "%b" @(hugo))x"
3. printf -v var "%b" @(hugo); echo "x${var}x"
# note: no file named hugo is allowed to reside in the current working
directory

Expected Behaviour:
2. xx
3. xx

Actual Behaviour:
2. xx
3. x/current/working/directory/*.@(m3|i3|ig|mg)x

Description:
  Statetements (2) and (3) are expected to have the same effect in any
situation.
  Yet this is apparently not the case if nullglob is enabled.
  If the -v option is used to store the result in a variable, printf
seems to ignore the nullglob setting.