t: teach lint that RHS of 'local VAR=VAL' needs to be quoted
Teach t/check-non-portable-shell.pl that right hand side of the
assignment done with "local VAR=VAL" need to be quoted. We
deliberately target only VAL that begins with $ so that we can catch
- $variable_reference and positional parameter reference like $4
- $(command substitution)
- ${variable_reference-with_magic}
while excluding
- $'\n' that is a bash-ism freely usable in t990[23]
- $(( arithmetic )) whose result should be $IFS safe.
- $? that also is $IFS safe
Signed-off-by: Junio C Hamano <gitster@pobox.com>