Re: Problems with Libtiff, Libpng

["Charles S. Wilson" <cwilson at ece dot gatech dot edu>]

Tom Weichmann wrote:
> 
> Hello,
> 
> I may have found a problem with LIBZ.DLL.  When using a binary
> distribution of Windowmaker from the xfree project, I get an error.
> When running 'wmaker' I get a dialog box stating:
> 
> Error Starting Program
> The LIBTIFF.DLL file is linked to missing export LIBZ.DLL:inflateInit_
> 
> The same error occurs in regards to LIBPNG as well.
> 
> I am running cygwin 1.1.3 on Win98

You really didn't supply enough information to debug the problem, but
here goes. I'm assuming you're using the -0.62.1 version of windowmaker
from 
ftp://my-favorite-sourceware-mirror/pub/cygwin/xfree/contrib/
windowmaker-0.62.1.tar.bz2

Okay. WM depends on libtiff.dll and libpng.dll.  Both libtiff.dll and
libpng.dll in turn depend on libz.dll.  Now, your system probably has
the official libtiff.dll and libpng.dll (from the tiff-3.5.5-2.tar.gz
and libpng-1.0.8-2.tar.gz cygwin packages).  Those two packages depend
*specifically* on the libz.dll from zlib-1.1.3-4.tar.gz. However, the WM
package includes its own libz.dll -- and OVERWRITES the correct one with
its private version.

When WM loads libtiff.dll and libpng.dll, the Windows dynamic loader
tries to resolve their dependency on the libz.dll (from -1.1.3-4) but it
fails to find the correct symbols -- since the new, private libz.dll
doesn't match the libtiff.dll and libpng.dll.

To fix, reinstall the zlib-1.1.3-4.tar.gz package.

I'm not trying to imply that you can't update zlib- or libpng- or
libtiff- independently of any other package. DLL's are supposed to allow
you to do that one-at-a-time library update. However, all of the dll's
must be compiled in the same way, so as to work together nicely.  WM's
libz.dll is probably somehow compiled in an way that is incompatible
with the official libtiff.dll and libpng.dll.

--Chuck

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