Array parameter expansion with non-space-IFS on bash-3/4

[Freddy Vulto]

I noticed different behaviour between bash-3 and bash-4 when
performing parameter expansion on an array with IFS set to a non-space
value.  For example, on bash-3.2.39, I get:

    $ bash -c 'IFS=:; printf "<%s>\n" "${@/q}"' x a b
    <a b>

Whereas on bash-4.0.33, I get:

    $ bash -c 'IFS=:; printf "<%s>\n" "${@/q}"' x a b
    <a>
    <b>

Bash-4 seems to give the desired result (leave the array intact), but
it's a bug on bash-3?

Regards,

Freddy Vulto
http://fvue.nl