Here's a patch from Rusty Russell through alikins to add --rsyncable to the gzip command line that shouldn't break anything else. FWIW, the equivalent patch for zlib is gonna be internalized in rpm for payload compression. You've been warned :-)
Created attachment 43620 [details] --rsyncable patch
What does this patch do - what is "--rsyncable" ?
If (and only if) --rsyncable is specified, then the compression algorithm changes to preserve rsync's block boundaries on compressed data. This leads to ~1% degradation in the size of the compressed text, but can lead to dramatic improvements when the compressed text is rsync'd. Try a google search on "gzip.rsync.patch2" for details, there's a talk given at a linux conference in Oz by Rusty Russell, more.
It was added in 1.3.2-3. It's just been removed, but that's a separate issue :).