On 20 September 2016 at 12:18, Alan Young <[email protected]> wrote:
> This is correct. 7zip is not the problem. The problem is the end user's > unzip application. The zip specification has been extended over time to > support additional compression methods. See > https://support.pkware.com/display/PKZIP/APPNOTE and > https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT. Section > 4.4.3.2 has a quick summary of the feature versions. The current PKzip > program will unzip the doc file created by 7zip. This would all be fine if the file in question was a ZIP file. According to my reading of even the latest version of the APPNOTE.TXT file, IBM's file does not meet the specs for a ZIP file. In particular, a required signature element is missing. Whether or not a particular commercial product from PKWARE will decode this file misses the point. It's not a question of new compression types; the entire file wrapper is plain wrong. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
