col: avoid extra newline if no input

BSD fix missed for 22 years, and all util-linux releases so far.

Backported-from: https://github.com/dspinellis/unix-history-repo/commit/2a15260a2a3230e02f57c096fb4c5e1f797bf4f3
Addresses: https://github.com/karelzak/util-linux/issues/422
Reported-by: Pavel Raiskup <praiskup@redhat.com>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/text-utils/col.c b/text-utils/col.c
index b236b891f7e419fd3abaec9b141179fd23ce4432..bac48e7e33e5cba3a35edb1094e397af5a1bf7a9 100644 (file)
--- a/text-utils/col.c
+++ b/text-utils/col.c
@@ -391,6 +391,8 @@ int main(int argc, char **argv)
        /* goto the last line that had a character on it */
        for (; l->l_next; l = l->l_next)
                this_line++;
+       if (max_line == 0)
+               return EXIT_SUCCESS;    /* no lines, so just exit */
        flush_lines(this_line - nflushd_lines + extra_lines + 1);
 
        /* make sure we leave things in a sane state */