Setting core global variables to odd things is causing failures

[shadowcat-mst]

This is triggering a complaint from a $fh->print inside Mail::Message that appears to be expecting $\ to be either undef or "\n" - and given the perldoc for the variable says that the default/empty value is undef, not "", I would argue that:

$, = "";      # output field separator is null string
$/ = "\n";    # input record separator is newline
$\ = "";      # output record separator is null string
$^W = 0;      # warnings are off

should be

$, = undef;   # output field separator is null string
$/ = "\n";    # input record separator is newline
$\ = undef;   # output record separator is null string
$^W = 0;      # warnings are off