For multi-volume archives the compressed size refers to the size of the data in the volume rather than the entire archive.
Signed-off-by: Laurent Aimar <fenrir@videolan.org>
(cherry picked from commit 0ea07fba5ac7677c715664d370c85cbf8ce01d95)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>