Bug 2009

Summary:	libXpm should use zlib for compression/decompression
Product:	xorg	Reporter:	Alan Coopersmith <alan.coopersmith>
Component:	Lib/Xpm	Assignee:	Xorg Project Team <xorg-team>
Status:	RESOLVED INVALID	QA Contact:	Xorg Project Team <xorg-team>
Severity:	enhancement
Priority:	high	CC:	jeremyhu, roland.mainz
Version:	git	Keywords:	love
Hardware:	All
OS:	All
Whiteboard:	2011BRB_Reviewed
i915 platform:		i915 features:

Description Alan Coopersmith 2004-12-03 16:56:57 UTC

Currently libXpm twists through a bunch of contortions to fork/exec compress
and gzip for reading and writing .xpm.Z and .xpm.gz files.   It would be simpler,
faster, and safer to simply use zlib to do this instead - any volunteers?

Comment 1 Alex Riesen 2004-12-04 09:18:26 UTC

zlib does not do LZW (.Z), does it?

Comment 2 Roland Mainz 2004-12-04 19:47:14 UTC

(In reply to comment #1)
> zlib does not do LZW (.Z), does it?

When I try % cat foo.Z | gunzip -c | less # I can read the uncompressed content
of "foo" ... sounds that somehow at least gunzip can read files made by
/usr/bin/compress (this doesn't gurantee that libz.so can handle this
compression by default, seems we would have to do some trial-n-error testing here :)

Comment 3 Alex Riesen 2004-12-05 05:07:07 UTC

my copy of gzip (GNU 1.3.5) by does not even use zlib.
It also can't compress in LZW.

Comment 4 Stéphane Loeuillet 2005-01-03 13:34:51 UTC

from gzip homepage :

gzip produces files with a .gz extension.
gunzip can decompress files created by gzip, compress or pack.
gzip was developed as a replacement for compress because of the UNISYS and IBM
patents covering the LZW algorithm used by compress.

so, gzip misses the .Z creation

zlib only does gz/LZ77

--------

any lib available that does the LZW compression ?

Comment 5 Daniel Stone 2007-02-27 01:24:46 UTC

Sorry about the phenomenal bug spam, guys.  Adding xorg-team@ to the QA contact so bugs don't get lost in future.

Comment 6 Jeremy Huddleston Sequoia 2011-09-24 17:19:27 UTC

libarchive?  http://code.google.com/p/libarchive/wiki/Examples

Comment 7 Adam Jackson 2018-06-12 19:09:53 UTC

Mass closure: This bug has been untouched for more than six years, and is not
obviously still valid. Please reopen this bug or file a new report if you continue to experience issues with current releases.

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