expand: Fix trailing newlines processing in backquote expanding

According to POSIX.1-2008 we should remove newlines only at the end of
the substitution. Newlines-only substitions causes dash to remove
newlines before beggining of the substitution. The following code:

    cat <<END
    1
    $(echo "")
    2
    END

prints "1<newline>2" instead of expected "1<newline><newline>2".

This patch fixes trailing newlines processing in backquote expanding.

Signed-off-by: Nikolai Merinov <n.merinov@inango-systems.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
1 file changed