Bug#885042: Check inclusion of Apache 2.0 NOTICE files

[Russ Allbery <rra@debian.org>]

Package: lintian
Version: 2.5.65
Severity: wishlist

Apache 2.0 requires distributing any NOTICE file along with derivative
works, but this is easy to forget.  In many cases, we have effectively
the same information in debian/copyright, but even if this is the case
for a specific release, it's not guaranteed to stay the case in the
future and it's easy to forget to check.

I think Lintian could warn if a NOTICE file exists in the source tree
and the package says in debian/copyright that it's under Apache 2.0, but
the NOTICE file is not included in the package documentation files.

-- System Information:
Debian Release: buster/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 4.14.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages lintian depends on:
ii  binutils                          2.29.1-12
ii  bzip2                             1.0.6-8.1
ii  diffstat                          1.61-1+b1
ii  dpkg                              1.19.0.4
ii  file                              1:5.32-1
ii  gettext                           0.19.8.1-4
ii  intltool-debian                   0.35.0+20060710.4
ii  libapt-pkg-perl                   0.1.33
ii  libarchive-zip-perl               1.60-1
ii  libclass-accessor-perl            0.51-1
ii  libclone-perl                     0.39-1
ii  libdpkg-perl                      1.19.0.4
ii  libemail-valid-perl               1.202-1
ii  libfile-basedir-perl              0.07-1
ii  libipc-run-perl                   0.96-1
ii  liblist-moreutils-perl            0.416-1+b3
ii  libparse-debianchangelog-perl     1.2.0-12
ii  libperl5.26 [libdigest-sha-perl]  5.26.1-3
ii  libtext-levenshtein-perl          0.13-1
ii  libtimedate-perl                  2.3000-2
ii  liburi-perl                       1.72-2
ii  libxml-simple-perl                2.24-1
ii  libyaml-libyaml-perl              0.63-2+b2
ii  man-db                            2.7.6.1-4
ii  patchutils                        0.3.4-2
ii  perl                              5.26.1-3
ii  t1utils                           1.41-2
ii  xz-utils                          5.2.2-1.3

Versions of packages lintian recommends:
pn  libperlio-gzip-perl  <none>

Versions of packages lintian suggests:
pn  binutils-multiarch     <none>
ii  dpkg-dev               1.19.0.4
ii  libhtml-parser-perl    3.72-3+b2
ii  libtext-template-perl  1.47-1

-- no debconf information