Bug#935706: lintian: Make tag certainty a programmatic assessment

[Felix Lechner <felix.lechner@lease-up.com>]

Package: lintian

Hi,

A tag's certainty is currently fixed but actually depends on the
programmatic circumstances of its issuance. Some heuristics are better
than others. The 'tag' command should offer alternatives, which then
result in different alert levels (error, warning, info, and so on).

An example are tags that depend on native or non-native sources. For a
source package, the determination is easy. For an installation package
(*.deb) there is no way to know for sure, but the version number may
offer a guess:

For source packages, the tag would be certain (from a pending version
of checks/source-changelog.pm):

    my $maintainer_revision = $latest_version->maintainer_revision;
(full version for native)
    tag->certain 'hyphen-in-native-debian-changelog-version',
$maintainer_revision
        if $info->native && $maintainer_revision =~ qr/-/;

while for installation packages (*.deb) it would not:

    my $version = $latest_entry->{Version}; (literal version string)
    tag->possible 'hyphen-in-native-debian-changelog-version', $version
        if [not sure this can be determined];

The first use would produce an error; the second, a warning.

For the new mechanism to work, overrides should exclude the alert
level. They would function more like the universal tag format used in
the test suite.

Kind regards,
Felix Lechner