GZIP Compression

Official gzip versions up to (and including) 1.4 will generate matching compression.

As of the 1.5 release, compression does not match. This is due to a bugfix in gzip:

2012-03-18  Paul Eggert  <[email protected]>

    gzip: fix nondeterministic compression results
    Reported by Jakub Wilk in <http://bugs.debian.org/647522>.
    * deflate.c (fill_window): Don't let garbage pollute the dictionary.

and the following line of code:

            /* Don't let garbage pollute the dictionary.  */
            memzero (window + strstart + lookahead, MIN_MATCH - 1);

If this line is removed, then we can get matching compression on the latest (1.10) gzip.