tech-pkg: tar ignores filenames that contain `..'

Subject: tar ignores filenames that contain `..'
To: None <current-users@netbsd.org, tech-pkg@netbsd.org>
From: Shin'ichiro TAYA <taya@ba2.so-net.ne.jp>
List: tech-pkg
Date: 10/23/2002 23:10:19

After switching to pax based tar, tar ignores filenames that contain `..'.
But some distfile for pkgsrc contains symlinks that points to file
contain '..' then failes to extract.
e.g.

=> Checksum OK for STLport-4.0.tar.gz.
===> Extracting for stlport-4.0nb2
===> Required installed package gmake>=3.78: gmake-3.79.1nb1 found
===> Required installed package libtool-base>=1.4.20010614nb9: libtool-base-1.4.20010614nb9 found
tar: Ignoring link containing `..' (../algorithm)
tar: Ignoring link containing `..' (../bitset)
tar: Ignoring link containing `..' (../cassert)

How should we fix this?
fix pkgsrc and related things? or /bin/tar ?