cURL / Mailing Lists / curl-library / Single Mail


Re: zlib and 64-bit

From: Cory Nelson <>
Date: Sun, 22 May 2005 17:07:42 -0700

On 5/22/05, Dan Fandrich <> wrote:
> On Sat, May 21, 2005 at 03:11:23PM -0700, Cory Nelson wrote:
> > When libcurl is compiled to use zlib, it crashes on gzipped data.
> >
> > When using zlib's file i/o functions directly, this crash doesn't
> > happen. Because the file i/o functions use the stream functions, I'm
> > betting it's not in the stream functions.
> >
> > Unfortunately VS2005 won't install for me on 64-bit (i have to
> > cross-compile then reboot into the 64-bit edition), so I can't debug.
> > I've been reviewing the significant portions of libcurl but I'm not
> > very familiar with it and havn't turned up anything, so I'm hoping
> > another set of eyes will be able to.
> >
> > I've attached a small test case, the URL's I've been using are
> > (works) and
> > (crashes)
> The attached test case does not set the CURLOPT_ENCODING option, so libcurl's
> gzip support is not enabled. Also, neither URL sets a Content-Encoding:
> header, so even if it were enabled, libcurl's gzip support would not be
> enabled. Whatever the source of the crash you are seeing, is doesn't seem to
> be related to libcurl's zlib support.
> I suspect the problem you're seeing is due to this warning in the libcurl
> documentation for CURLOPT_WRITEDATA:
> NOTE: If you're using libcurl as a win32 DLL, you MUST use the
> CURLOPT_WRITEFUNCTION if you set this option or you will experience
> crashes.

Except this is in a 100% statically linked exe. Also, both urls work
fine when it's not compiled to use zlib.

> >>> Dan
> --
> The web change of address service
> Let webmasters know that your web site has moved

Cory Nelson
Received on 2005-05-23