nl: ensure '-b n' option displays file content

The command 'nl -b n' should output no line numbers, just some
spaces as a placeholder followed by the actual file content.

Add tests for line numbering by cat and nl.  The correct results
were obtained from coreutils.

function                                             old     new   delta
print_numbered_lines                                 152     157      +5
.rodata                                           182456  182453      -3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 5/-3)                Total: 2 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/libbb/print_numbered_lines.c b/libbb/print_numbered_lines.c
index d6459d7c3..4758068a4 100644
--- a/libbb/print_numbered_lines.c
+++ b/libbb/print_numbered_lines.c
@@ -22,10 +22,11 @@ int FAST_FUNC print_numbered_lines(struct number_state *ns, const char *filename
                 if (ns->all
                  || (ns->nonempty && line[0])
                 ) {
-                        printf("%*u%s%s\n", ns->width, N, ns->sep, line);
+                        printf("%*u%s", ns->width, N, ns->sep);
                         N += ns->inc;
                 } else if (ns->empty_str)
                         fputs(ns->empty_str, stdout);
+                puts(line);
                 free(line);
         }
         ns->start = N;