Bug#506271: lintian: weirdness when checking manpages with nroff ignore commands

[Morten Kjeldgaard <mok@bioxray.au.dk>]

Package: lintian
Version: 1.24.2.1
Severity: normal

I was not able to get rid of lintian warnings in some man pages that made
extensive use of the nroff ignore (.ig) command. I tracked down the problem
to a weird behaviour of man.

It seems lintian uses the command "man -l --warnings" to check the sanity
of a manpage.

I did some experiments Using the following test manpage tst.1:

..TH TST 1 "Nov 2008"
..SH NAME
tst \- Test man page
..SH SYNOPSIS
tst -a -b -c
..SH DESCRIPTION
..nr Pb 0
..if \n(Pb .ig ZZ
I see this!
..ZZ
Yes yes, this text is always visible.
..if !\n(Pb .ig ZZ
I don't see this text, if Pb is zero!
..ZZ

Using the lintian command string:

$ man -l --warnings  tst.1 > /dev/null
<standard input>:10: warning: `ZZ' not defined

it is seen that man complains about the last .ZZ, which is perfectly
legal. However, running this:

$ man -l --warnings=all  tst.1 > /dev/null

gives no output. The same is true for:

$ nroff -man -wall tst.1 > /dev/null

I don't understand what's going on here, but it seems that the
--warnings option alone on man triggers a buggy behaviour. I suggest
that the checking string in lintian is changed so it uses nroff
directly, since that is what is invoked by man anyway.

-- System Information:
Debian Release: lenny/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: i386 (i686)

Kernel: Linux 2.6.26-1-686 (SMP w/2 CPU cores)
Locale: LANG=en_DK.UTF-8, LC_CTYPE=en_DK.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages lintian depends on:
ii  binutils            2.18.1~cvs20080103-7 The GNU assembler, linker and bina
ii  diffstat            1.45-2               produces graph of changes introduc
ii  dpkg-dev            1.14.22              Debian package development tools
ii  file                4.26-1               Determines file type using "magic"
ii  gettext             0.17-4               GNU Internationalization utilities
ii  intltool-debian     0.35.0+20060710.1    Help i18n of RFC822 compliant conf
ii  libparse-debianchan 1.1.1-2              parse Debian changelogs and output
ii  libtimedate-perl    1.1600-9             Time and date functions for Perl
ii  liburi-perl         1.35.dfsg.1-1        Manipulates and accesses URI strin
ii  man-db              2.5.2-3              on-line manual pager
ii  perl [libdigest-sha 5.10.0-16            Larry Wall's Practical Extraction 

lintian recommends no packages.

Versions of packages lintian suggests:
pn  binutils-multiarch            <none>     (no description available)
pn  libtext-template-perl         <none>     (no description available)
ii  man-db                        2.5.2-3    on-line manual pager

-- no debconf information