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RE: zlib issue

From: Fred Covely <fcovely@bcftech.com>
Date: Tue, 12 Mar 2002 20:38:17 -0500 (EST)
To: <Phil.Nitschke@youramigo.com>
Cc: <www-lib@w3.org>
Message-ID: <NDBBIGEEOLAKIPFCDMLNCENCHLAA.fcovely@bcftech.com>
After looking at that, it does not appear that is my problem, mine seems to
be something more fundamental in libwww.  I have a fix in but must be
building libwww in such a way that it does not work.  If I strip the zlib
header bytes of the data, it all works great, so for the moment I am going
with that approach.


Fred Covely
BCF Technology

-----Original Message-----
From: www-lib-request@w3.org [mailto:www-lib-request@w3.org]On Behalf Of
Phil Nitschke
Sent: Tuesday, March 12, 2002 5:22 PM
To: Fred Covely
Cc: www-lib@w3.org
Subject: Re: zlib issue

>>>>> "FC" == Fred Covely <fcovely@bcftech.com> writes:

  FC> Is anyone else have problems with sites that send back gzip
  FC> encoded data?

  FC> For example, if I do a simple HTTP Get on www.google.com accepting
  FC> gzip, I get no output.  I have traced this to htzip.c where the
  FC> call to the zlib function 'inflate' returns -3 (bad gzip format).
  FC> By various manueverings I can force it to accept the google zip
  FC> data, but I have been unable to make it work with 5.3.2.

  FC> FYI here is more detail on the work around.

  FC> The data that comes in from google is in gzip format and contains
  FC> the gzip header.  htzip.c seems to choke on the header piece, so I
  FC> borrowed a piece of code from zlib itself that reads past the
  FC> header before calling 'inflate'.  With that fix in libwww seems to
  FC> work fine.  I feel I am definitely missing something as I can't
  FC> believe others are not retrieving gzip encoded data.

Hi Fred,

Have you read the CERTŪ Advisory CA-2002-07 titled "Double Free Bug in
zlib Compression Library"?

While I'm not suggesting that this is the cause of the problem you're
seeing, it still may be advisable to review which version of zlib you're

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Received on Thursday, 14 March 2002 03:27:09 UTC

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