[Bug-tar] Problem with multiple archives and --concatenate

[Paul Fee]

Hello all,

The documentation for GNU tar suggests that multiple
archives can be appended onto an existing archive.

e.g.
tar --concatenate --file=first.tar append1.tar
append2.tar

However I find that I must append the archives one by
one in order to get the desired output in the merged
tar file.

Here is set of commands illustrating the problem:
----------
$ echo start > start
$ echo one > one
$ echo two > two
$ tar cf first.tar start
$ tar cf second.tar start
$ tar cf append1.tar one
$ tar cf append2.tar two

$ tar --concatenate --file=first.tar append1.tar
append2.tar

$ tar --concatenate --file=second.tar append1.tar
$ tar --concatenate --file=second.tar append2.tar

$ tar tf first.tar
start
one

$ tar tf second.tar
start
one
two
------------------
I would expect both first.tar and second.tar to have
the same contents.  The problem is first.tar doesn't
list file "two".  However examining the contents of
the file reveals that "append2.tar" has been added,
but the content is not retrievable.

$ cat -v first.tar | grep two

Here's the documentation I read:
http://www.gnu.org/software/tar/manual/tar.html#SEC58

The text includes "name the rest of archives to be
concatenated on the command line".

Because "archives" is plural, this suggests to me that
multiple tar files can be concatenated in one tar
command.

To me it looks like either the documentation should be
clarified or there's a bug in GNU tar.

Hopefully someone in this list can help decide which
explanation is appropriate.

Thank you,
Paul

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