Bug#901952: can affect packaged with old source tarballs

[Hans-Christoph Steiner]

I think this bug does qualify as RC since it can affect any source
tarball that was created with an older version of tar.  So it is not
just that it comes from a different distro/release than buster, but it
could be from a package that has a source tarball that hasn't changed
since tar 1.30.