Bug#698930: lintian: Have $info->index follow (safe) "symlinks" transparently

[Niels Thykier <niels@thykier.net>]

Package: lintian
Version: 2.5.11
Severity: wishlist

Currently, the use of $info->index ('some/path') does not give any
result if "some" is a symlink to a(n existing/known) directory in the
package.  Consider:

  debian -> debian-packaging
  debian-packaging/control

Here, $info->index ('debian/control') will return undef.

It is possible $info->index should have an "opt-out" variant for cases
where symlinked paths are not permitted[1].  Anyway, I believe this
would greatly simply usage of $info->index for usage of (non-broken)
symlinks.
  Particularly would make it easier to migrate our existing
source checks which are currently using "opendir" on the actual
unpacked package (without causing regressions)[2].

~Niels

[1] Perhaps "usr/share/doc/<pkg>/copyright" ?  Under the assumption
that if <pkg> is a symlink, it should generally be a symlink to a
"foreign" package.

[2] examples include checks/debhelper and checks/debian-source-dir.