cperl-break-one-line-blocks-when-indent

cperl-break-one-line-blocks-when-indent is a variable defined in `cperl-mode.el'.
Its value is

t

Documentation:
*Non-nil means that one-line if/unless/while/until/for/foreach BLOCKs
need to be reformatted into multiline ones when indenting a region.

You can customize this variable.