[pacman-dev] delta support in libalpm

[Xavier]

On Fri, Nov 14, 2008 at 1:02 PM, Nagy Gabor <ngaba at bibl.u-szeged.hu> wrote:
>>
>> I guess I spoke to soon. I was right concerning xdelta3 using gzip for
>> handling gzipped files, however it doesn't use the -n flag. This gives
>> us the same behaviour as xdelta1, with one minor difference: Method 1.
>> stops working.
>
> Wait. I don't understand something. If it doesn't use the -n flag, how can
> we produce an md5sum-identical patched file? (The mtime is unpredictable.)
> This poses an extra problem, or not? I just did an effective test on
> xdelta3-diffing .tar.gz files and I saw that the patched md5sum indeed
> differ from the original one :-( Maybe we should search for a gzip header
> manipulation tool...
>

One of the proposal was to use gzip -n, which should fix this problem.