[Openexr-devel] Issue with libz library 1.2.x version and OpenEXR

[Jeff Clifford]

Hi,

I have successfully compiled up 32 and 64-bit versions of the openEXR 
libs for our 64-bit Fedora Core 4 machines.

The libraries have been working fine until I used ZIP compression when 
writing a file.  This caused a seg fault at the line:

   file.writePixels( header.dataWindow().max.y - 
header.dataWindow().min.y + 1);

Suspicious of an error else where in code I ran the program through 
Valgrind to check if they were any other causes and where exactly the 
problem was.  There were no other errors, just this:

==8576== Invalid write of size 2
==8576==    at 0x342FE0582B: (within /usr/lib64/libz.so.1.2.2.2)
==8576==    by 0x342FE0478E: deflate (in /usr/lib64/libz.so.1.2.2.2)
==8576==    by 0x342FE025BB: compress2 (in /usr/lib64/libz.so.1.2.2.2)
==8576==    by 0x55C08B: Imf::ZipCompressor::compress(char const*, int, 
int, char const*&) (in /u/jbc/tools/bin/Linux64/exrwriter)
==8576==    by 0x5557B7: Imf::OutputFile::writePixels(int) (in 
/u/jbc/tools/bin/Linux64/exrwriter)

If I change the line

header.compression() = Imf::ZIP_COMPRESSION;

to any other compression (except ZIPS) or no compression everything 
works fine.


I then decided to check what version of the zlib came on the 32-bit 
RedHat9 machines machines which worked fine with no seg fault (1.1.4).

First off I tried upping the zlib version to 1.2.3 (the latest release) 
but still the seg fault occured.

I then rolled back the version of zlib on our Fedora Core 4 machines to 
1.1.4 and the seg fault stopped.  I found that rolling back both the 
32-bit and 64-bit versions of the zlib library fixed both the 32-bit and 
64-bit verions of the program on the Fedora Core 4 machines.

I just wondered if this is a known issue or whether anyone else has any 
experience of such problems?  Is there something I need to do to be able 
to use the later zlib version?


Thanks,

Jeff Clifford.