Wireshark-users: Re: [Wireshark-users] Upgraded wireshark to 1.2.6 but now old pcap files cannot
From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Tue, 23 Mar 2010 19:32:56 -0700
On Mar 23, 2010, at 7:04 PM, Kok-Yong Tan wrote:

> I'm not sure.  I wiped the entire MacPorts installation and the  
> whole /opt/local tree and restarted from scratch by downloading the  
> Tiger version of MacPorts, installing it, then typing "port install  
> wireshark".

If it was built with a version of libz earlier than 1.2.4, this might either be

	1) a bug in libz 1.2.4

or

	2) a bug in Wireshark, where it was using libz incorrectly in a fashion that happened to work with earlier versions of libz but doesn't work with libz 1.2.4

as

	1) somebody else had a similar problem with Wireshark on Gentoo Linux, and Wireshark was using libz 1.2.4 there

and

	2) one of the changes in libz 1.2.4 was the "Wholesale replacement of gz* functions with faster versions", those being the routines Wireshark uses to read capture files when built with libz support.

Those routines are used even to read *uncompressed* files (the gz* routines in libz handle figuring out whether the file is compressed or not, and hides that from the application reading the file).