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Re: fun variation in hdr.unload()

On Mon, Apr 28, 2003 at 11:06:24AM -0400, seth vidal wrote:
> > Signature tags are appended to package header. Nothing else changes,
> > that's the whole point of a "immutable header region".
> > 
> > However, with the bindings, it depends a lot on how you choose to read
> > the original header. rpm cannot dictate where and how you got the header
> > from.
> > 
> After some more experimentation I just realized it is not hdr.unload()
> it's the gzipping of the headers that's causing it.
> now I have to figure out why gzipping the same file varies so much.

Ah, that's easier to explain. gzip/zlib transformations are idempotent
(i.e. exactly invertible) iff the dictionary flushes happen at exactly
the same points. So it's quite possible (probable in fact) that
you will get different results between gzip/zlib and there's some additional
funkiness with rpm's internal zlib that's different than zlib-1.0.4.

73 de Jeff

Jeff Johnson	ARS N3NPQ
jbj@redhat.com (jbj@jbj.org)
Chapel Hill, NC

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