if (all)
die("git-checkout-index: don't mix '--all' and explicit filenames");
if (read_from_stdin)
die("git-checkout-index: don't mix '--stdin' and explicit filenames");
if (all)
die("git-checkout-index: don't mix '--all' and explicit filenames");
if (read_from_stdin)
die("git-checkout-index: don't mix '--stdin' and explicit filenames");