When a new archive is created by tar command, the archive includes a same name file of itself

Issue

• When a new archive with the current directory is created on the current directory by using tar command, the archive includes a same name file of itself.

 # ll
 total 8
 -rw-r--r-- 1 root root 185 Jun 25 13:57 hosts  (sample file)

 # tar czf AAA.tar.gz ./
 # tar tvzf AAA.tar.gz
 drwxr-xr-x root/root         0 2012-06-25 13:58:04 ./
 -rw-r--r-- root/root       185 2012-06-25 13:57:43 ./hosts
 -rw-r--r-- root/root         0 2012-06-25 13:58:04 ./AAA.tar.gz  (the stored archive)