$* vs ${ARRAY[*]} differences in some parameter expansions

[Grisha Levit]

bash currently handles all parameter expansions with $* and $@ as described in interpretation 888, and the behavior when using an array subscripted with @ matches identically the behavior of the examples concerning $@.  However, the behavior when using an array subscripted with * does not always match the behavior of the examples concerning $*.

This difference is surprising since otherwise the behaviors are identical (though I'm not sure if would be proper to call this a "bug" since the isomorphism is not explicitly defined in the documentation).

$ set -- "abc" "def ghi" "jkl"

$ A=("$@")

----

$ IFS=':'

$ unset var; printf '%s\n' ${var-$*}

abc

def ghi

jkl

$ unset var; printf '%s\n' ${var-${A[*]}}

abc def ghi jkl

----

$ unset  var; printf '%s\n' ${var=$*}

abc

def ghi

jkl

$ printf 'var=%s\n' "$var"

var=abc:def ghi:jkl

$ unset var; printf '%s\n' ${var=${A[*]}}

abc def ghi jkl

$ printf 'var=%s\n' "$var"

var=abc def ghi jkl

----

$ IFS=''

$ unset var; printf '%s\n' ${var-$*}

abcdef ghijkl

$ unset var; printf '%s\n' ${var-${A[*]}}

abc

def ghi

jkl

----

$ unset var; printf '%s\n' ${var=$*}

abcdef ghijkl

$ printf 'var=%s\n' "$var"

var=abcdef ghijkl

$ unset var; printf '%s\n' ${var=${A[*]}}

abc

def

ghi

jkl

$ printf 'var=%s\n' "$var"

var=abc def ghi jkl