Bug#765995: lintian: Use of uninitialized value $base in substitution (s///) at /usr/share/lintian/checks/watch-file.pm line 137, <$_[...]> line 2.

[Axel Beckert <abe@debian.org>]

Package: lintian
Version: 2.5.28
Severity: minor

Dear Lintian Maintainers,

a broken debian/watch file caused an interesting lintian behaviour.
Given a watch file like this:

version=3
opts=pgpsigurlmangle=s/$/.asc/ 
http://www.example.com/Downloads/code-(.+)code\.zip

This watch file has two issues:

* No continuation line indicating backslash in line 2
* A trailing blank in line two.

Only if both constraints are present, lintian throws this Perl warning:

Use of uninitialized value $base in substitution (s///) at /usr/share/lintian/checks/watch-file.pm line 137, <$_[...]> line 2.

If I remove the trailing blank, I get the
debian-watch-may-check-gpg-signature warning, if I add a trailing
backslash, everything is fine.

-- System Information:
Debian Release: jessie/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (600, 'testing'), (110, 'experimental'), (109, 'buildd-unstable'), (109, 'buildd-experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 3.17-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages lintian depends on:
ii  binutils                       2.24.90.20141014-1
ii  bzip2                          1.0.6-7
ii  diffstat                       1.58-1
ii  file                           1:5.20-1
ii  gettext                        0.19.2-3
ii  hardening-includes             2.6
ii  intltool-debian                0.35.0+20060710.1
ii  libapt-pkg-perl                0.1.29+b2
ii  libarchive-zip-perl            1.38-1
ii  libclass-accessor-perl         0.34-1
ii  libclone-perl                  0.37-1+b1
ii  libdpkg-perl                   1.17.18
ii  libemail-valid-perl            1.195-1
ii  libfile-basedir-perl           0.03-1
ii  libipc-run-perl                0.92-1
ii  liblist-moreutils-perl         0.33-2+b1
ii  libparse-debianchangelog-perl  1.2.0-1.1
ii  libtext-levenshtein-perl       0.09-1
ii  libtimedate-perl               2.3000-2
ii  liburi-perl                    1.64-1
ii  man-db                         2.7.0.2-2
ii  patchutils                     0.3.3-1
ii  perl [libdigest-sha-perl]      5.20.1-1
ii  t1utils                        1.38-1

Versions of packages lintian recommends:
ii  libautodie-perl                 2.25-1
ii  libperlio-gzip-perl             0.18-3+b1
ii  perl                            5.20.1-1
ii  perl-modules [libautodie-perl]  5.20.1-1

Versions of packages lintian suggests:
ii  binutils-multiarch     2.24.90.20141014-1
ii  dpkg-dev               1.17.18
ii  libhtml-parser-perl    3.71-1+b2
ii  libtext-template-perl  1.46-1
ii  libyaml-perl           1.13-1
ii  xz-utils               5.1.1alpha+20120614-2

-- no debconf information