cut: improve detection of invalid ranges

Commit 0068ce2fa (cut: add toybox-compatible options -O OUTSEP,
-D, -F LIST) added detection of reversed ranges.  Further
improvements are possible.

- The test for reversed ranges compared the start after it had been
  decremented with the end before decrement.  It thus missed ranges
  of the form 2-1.

- Zero isn't a valid start value for a range.  (Nor is it a valid
  end value, but that's caught by the test for a reversed range.)

- The code

        if (!*ltok)
            e = INT_MAX;

  duplicates a check that's already been made.

- Display the actual range in the error message to make it easier
  to find which range was at fault.

Adds 0-48 bytes.

(GitHub issue #467)

0 files changed, 0 insertions, 0 deletions