expansion and redirections

[Telychko]

Hi.

Recently i found this feature(or bug):

its reproduce interactively

$exec 3</dev/zero    # open /dev/zero on 3
$VAR=3               # have some variable with file descriptor
$exec $VAR<&-        # trying to close previously opened file descriptor
bash: exec: 3: not found

so we have expansion $exec $VAR<&- --> $exec 3 <&- ... why not $exec 3<&-

$exec 3<&-     # close normally

Best regards.