file-roller 3.6.0 does not extract hardlinks from a tarball.

It only extracts one of the hardlinked files, and silently skips other hardlinks from the archive.

Prepare an archive with hardlinks:
$ mkdir file-roller-archive
$ touch file-roller-archive/a
$ ln file-roller-archive/a file-roller-archive/b
$ ls -lh file-roller-archive 
total 0
-rw-r--r-- 2 blino blino 0 Oct 13 00:56 a
-rw-r--r-- 2 blino blino 0 Oct 13 00:56 b
$ tar cvvf file-roller-archive.tar file-roller-archive/
drwxr-xr-x blino/blino       0 2012-10-13 00:56 file-roller-archive/
-rw-r--r-- blino/blino       0 2012-10-13 00:56 file-roller-archive/b
hrw-r--r-- blino/blino       0 2012-10-13 00:56 file-roller-archive/a link to file-roller-archive/b

Now extract the archive with file-roller, keeping directory structure.
$ rm -rf file-roller-archive
$ file-roller file-roller-archive.tar
$ ls -lh file-roller-archive
total 0
-rw-r--r-- 1 blino blino 0 Oct 13 00:56 b

The "a" hardlinked file is missing.

The tar utility correctly extracts both hardlinked files:
$ rm -rf file-roller-archive
$ tar xvvf file-roller-archive.tar 
drwxr-xr-x blino/blino       0 2012-10-13 00:56 file-roller-archive/
-rw-r--r-- blino/blino       0 2012-10-13 00:56 file-roller-archive/b
hrw-r--r-- blino/blino       0 2012-10-13 00:56 file-roller-archive/a link to file-roller-archive/b
$ ls -lh file-roller-archive 
total 0
-rw-r--r-- 2 blino blino 0 Oct 13 00:56 a
-rw-r--r-- 2 blino blino 0 Oct 13 00:56 b