pr: leading zeros omitted with certain arguments to the -n option

[Ondrej Oprala]

Hi,
we've had a bug report from one of our customers recently, saying
pr -nNUM doesn't zero-pad line numbers on output with certain
values of NUM (for example 1-11, 13-14, 16-17...). The problem
seems to be the faulty format string that I fixed in the patch
attached. I've also added 2 test cases in tests/misc/pr.pl to
exercise the output with problematic as well as ok NUM values.
Cheers,
Ondrej

>From 78e32d37ba174a50dad86b5b6d557a76755b957d Mon Sep 17 00:00:00 2001
From: Ondrej Oprala <oopr...@redhat.com>
Date: Wed, 24 Oct 2012 10:49:05 +0200
Subject: [PATCH] pr: fix omitted leading zeros with particular arguments to
 -n option

* NEWS: Mention the fix.
* src/pr.c (add_line_number): Change sprintf format string.
* tests/misc/pr.pl: Add a test case to exercise the change.
---
 NEWS             | 5 +++++
 src/pr.c         | 2 +-
 tests/misc/pr.pl | 6 +++++-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/NEWS b/NEWS
index 04721da..6b1a99b 100644
--- a/NEWS
+++ b/NEWS
@@ -2,6 +2,11 @@ GNU coreutils NEWS                                    -*- 
outline -*-
 
 * Noteworthy changes in release ?.? (????-??-??) [?]
 
+** Bug fixes
+
+  pr now properly zero-pads line numbers with arbitrary integer
+  arguments to the -n option.
+
 
 * Noteworthy changes in release 8.20 (2012-10-23) [stable]
 
diff --git a/src/pr.c b/src/pr.c
index e97c434..45e80e1 100644
--- a/src/pr.c
+++ b/src/pr.c
@@ -2034,7 +2034,7 @@ add_line_number (COLUMN *p)
   /* Cutting off the higher-order digits is more informative than
      lower-order cut off*/
   if (line_number < power_10)
-    sprintf (number_buff, "%*d", chars_per_number, line_number);
+    sprintf (number_buff, "%0*d", chars_per_number, line_number);
   else
     {
       left_cut = line_number % power_10;
diff --git a/tests/misc/pr.pl b/tests/misc/pr.pl
index 0f25e25..383b4ef 100755
--- a/tests/misc/pr.pl
+++ b/tests/misc/pr.pl
@@ -1,5 +1,5 @@
 #!/usr/bin/perl
-# Exercise a bug with pr -m -s
+# Exercise a bug with pr -m -s and -n
 
 # Copyright (C) 2007-2012 Free Software Foundation, Inc.
 
@@ -33,6 +33,10 @@ my @Tests =
     {IN=>{2=>"m\tn\to\n"}},
     {IN=>{3=>"x\ty\tz\n"}},
      {OUT=>join("\t", qw(a b c m n o x y z)) . "\n"} ],
+   ['zeros1', '-n10 -t',
+    {IN=>"abc\n"}, {OUT=>"0000000001   abc\n"}],
+   ['zeros2', '-n12 -t',
+    {IN=>"abc\n"}, {OUT=>"000000000001 abc\n"}],
   );
 
 my $save_temps = $ENV{DEBUG};
-- 
1.7.11.7