[Bug-tar] gnu tar bug: tar adds junk at the end of archive

[Stas Kysel]

Hi.

When tar is using stdout for writing archive, it adds junk after the end
of archive:

# mkdir 1
# echo qqqqqqqq >1/2
# tar cfz - 1 >4 ; tar cfz 5 1
# ls -l 4 5
-rw-r--r--    1 root     root        10240 Jul 30 02:29 4
-rw-r--r--    1 root     root          140 Jul 30 02:29 5
# uname -a
Linux XXXX.XXX.XXX 2.4.20-19.8 #1 Tue Jul 15 15:14:07 EDT 2003 i686 i686 i386 
GNU/Linux
# tar --version
tar (GNU tar) 1.13
Copyright (C) 1988, 92,93,94,95,96,97,98, 1999 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by John Gilmore and Jay Fenlason.

1. strace shows that gzip writes 140 bytes to tar, but tar writes 10k bytes
to stdout.
2. old tar (1.11) does not put junk
3. tar-1.13.25 on FreeBSD does put junk

-- 
Stas Kysel, UNIX Systems Administrator of Yessoftware Inc