From: gt0040a@prism.gatech.EDU (Tom Sorensen)
Newsgroups: comp.compression
Subject: PKZip 2.04C bug list, #4
Keywords: PKZip, bug
Date: 25 Jan 93 17:29:03 GMT
Organization: Georgia Institute of Technology


I am keeping a listing of the known PKZip 2.04C bugs and posting them as
I find out about them. In order to keep things simple all information is
posted at one time- both old and new info is in this file. As new bugs
come up they'll be added to the beginning of the file. I've also created
a list of common complaints by users.

This is revision 4. New info is marked by a *. Changed info is marked by
a !.

Clearly despite the one year delay not all the bugs got squashed. Note
that not all bugs will be experienced by all users. Most are *HIGHLY*
machine and configuration dependant.

As of 1/11/93 at 5:00 pm EST PKWare is working on a bug fix for 2.04C.
It is at internal beta stage. The disk spanning, volume label, and
EMS/XMS/DPMI problems are to be solved. The manual should also be fixed.

PKZip 2.04C bugs:

* PKCFG.EXE (which comes with the registered product) produces an
incorrect CFG file if you want maximum compression. Instead of
COMPRESS=MAXIMUM it puts COMPRESS=MAXIMAL (which is also "misprinted" in
the manual).

* When viewing multiple disk archives you must do the view on the LAST
disk. Viewing the first disk results in a prompt for the last disk.
Viewing "middle" disks results in a perpetually spinning disk drive.

* Having ZIPFILE=latest in PKZIP.CFG and -& on the commandline causes
PKZIP to come up with the help screen. -o- does not help.

Note to SYSOPs: make sure you do not have -x in your PKZIP/UNZIP
strings. Doing so will cause the PKZip help screen to appear,
effectively hanging your system.

! Lines regarding XMS in PKZIP.CFG are ignored. Only the command line
switch -- works. Additionally EMS=disabled disables *BOTH* EMS and XMS.

Under Novell Netware Lite PKZIP does not erase temporary files.

Having EMS enabled can cause CRC errors and trashing of QWK packets
on some machines. This seems to be most prevalent under EZ-Reader v1.39.

Another manual error: the -o switch sets the ZIP date to the LATEST
file, not the oldest. Online help states it correctly.

! When you create a ZIP with directories in it 0-byte files with the
names of the directories are stored inside the ZIP. These "files" can
later be deleted with no damage to functionality. A collateral effect is
an incorrect file count when the ZIP file is viewed.

Older versions of Norton Anti-Virus report that PKZ204C has a mutant
strain of the Malaysian Amoeba Virus. This is a false positive- PKZ204C
is clean. (Note this info is quite old, but just didn't get onto this
list until now)

! The AV (Authenticity Verification) was compromised a few hours after
release. I HAVE confirmed this- I have exchanged several e-mail messages
on the Internet with the person who broke the AV. I will not divulge the
method (since he doesn't want it public knowledge, and I assume PKWare
doesn't either) but it only affects pre-AV'd files and does NOT generate
new AVs. Still, this means that a supposably secure ZIP file really has
no protection- files inside the ZIP may be modified and still leave the
AV intact. As of Monday, 1/18/93 at aprox. 2:00pm EST PKWare was
ignoring the problem. Please contact them and tell them that ignoring
*ANY* potential security violation regarding AVs is *NOT* acceptable.
The method the programmer used is actually rather simplistic and easily
implemented.

! Several users have reported their FAT being trashed after using PKZip.
I have also had some reports of the CMOS being wiped or otherwise
changed. This seems to be related to DPMI usage- the faulty DPMI
implementation can cause severe memory corruption which can lead to the
above problems. If anyone can give me the above info please tell me.

! Using -&f can cause problems. Bad sectors on the floppies will be
unmarked and used, causing later data loss. Other users have reported
that using -&f will corrupt the floppies FAT, rendering it unusable.
PKZip still tries to use it though. (This occurs w/ previously formatted
disks)

The multi-disk spanning ability of PKZip is highly unreliable. PKZip
will report false CRC errors if any single file spans a disk (ie- if you
are zipping up several files, and the 5th file must be split between the
two disks, false CRC errors will be reported). A later PKZip -t reports
the ZIP to be fine. Other reports of problems have been reported. It is
not suggested that you use PKZip to back up your HD.

PKZip may report CRC errors if you are unzipping a file that has its
path stored (-rp) and the file already exists. There are no CRC errors
if the file does not exist.

! DPMI support causes machines to crash. This occurs under QEMM, Windows,
and OS/2. PKWare suggests that all users use -) to disable DPMI support
at all times. OS/2 users may also disable DPMI support and/or eliminate
DPMI memory from DOS sessions. In most cases there are no problems under
386Max, QEMM's 1.01 DPMI revision, or w/ DPMI_DOS_API set to ENABLED
under OS/2.

Using PKZip & PKUnzip in a batch file can cause erroneous CRC errors and
prompts for "Insert disk 1 in drive A:". Cause is unknown. The exact
same commands work fine if executed from the command-line.

The manual is both incorrect and confusing in places. Specifically, on
pages 76 and 77 of the manual:

COMPRESS=MAXIMAL
should be
COMPRESS=MAXIMUM

Also, the usage of the EMS, XMS, and DPMI settings are unclear. In the
table they are shown as enable/disable, but in the examples on/off is
used. The correct usage is enable/disable.
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Complaints. The following are a list of common complaints about the new
version. Some users consider them bugs while others consider them
features. In all cases, please let PKWare know how you feel on the
issues.

* Some users have complained that PKZIP can't create compressed archives
extractable by PKUNZIP 1.10.

* PKZIP and PKUNZIP handle command-line parameters differently. PKUNZIP
doesn't care about order- -)+ means disable *BOTH* DPMI and EMS usage.
PKZIP, on the other hand, IS order dependant. -)+ means enable DPMI.
-+) gets identical results to PKUNZIP. This inconsistancy only further
confuses users and makes no sense.

PKZIP and PKUNZIP currently have completely separate methods of
configuration. PKZIP uses a CFG file while PKUNZIP uses an environment
variable. Some users have commented that this doesn't make sense- both
should use the configuration file. Either can easily ignore directives
that do not apply.

The multi-disk spanning function is feature poor. Many users want the
ability to create the files on a non-removable media for uploading or
other functions. In other words, do it like ARJ does.

! When using the -m switch with -r subdirectories are deleted along with
the files. This behavior is different from the 1.10 behavior and has
disgruntled several users. In particular, it causes problems for BBS
SYSOPs who expect temporary directories to still be there afterwards.

Several users have complained that the PKZ204C does not report older AV
stamps. This is due to the old AV being compromised. PKWare's official
stance is that due to this security break 204C should *NOT* report 1.10
AVs.
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I would like to thank everyone who has contributed to this list, and
there are too many to mention specifically. Keep the good work up and
hope PKWare kills these bugs soon!

This list is posted to ILink PKWare and Shareware conferences, the RIME
PKWare conference, and comp.compression. If you feel that this list
would be of use to others please feel free to post it. In particular I
would like to see it distributed onto Fidonet and other networks. My
only request is that this message be posted in its entirety, including
headers and footers. The contact information is most important. You may
delete the tagline though! <grin>

If you have any more reports or can give substantiation on some of the
bugs (batch, FAT problems, AV code) please contact me. I am available on
ILink PKZip, RIME PKZip, and Internet in comp.compression or e-mail at
gt0040a@prism.gatech.edu.
    Tom Sorensen
-- 
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Tom Sorensen              gt0040a@prism.gatech.edu
"I believe OS/2 is destined to be the most important operating system,
and possibly program, of all time." - Bill Gates, November, 1987