Bug#749319: duplicate items in manifest

[Mike Isely <isely@isely.net>]

Hi,

We've also encountered this problem, with kexec-tools.

Root cause aopears to be that the original upstream tarball likely has 
duplicate entries and the behavior in tar for handling duplicate entries 
has changed bewteen squeeze and wheezy.  Thus trying to recreate a 
tarball in one environment that has been generated in the other yields a 
different result, and that prevents xdelta from doing its job, ending 
with failure.

In one tar version (the one from Squeeze, I think), tar apparently 
doesn't do anything special to deal with duplicates - it just writes 
extra copies into the tarball when encountered.

But the other tar version (Wheezy), tar notices these and apparently 
substitutes a self-referenced sym-link for the duplicate entries.  
(Some kind of optimization perhaps?)

So the failure comes from the different tarball generation, but that 
ultimately stems from different behavior in handling duplicate entries 
in the original upstream tarball, which really should not have happened 
in the first place.

The kexec-tools package has the same issue.  Just do a tar tvf of, say, 
kexec-tools_2.0.3.orig.tar.gz in pool/main/k/kexec-tools, and you'll see 
multiple instances of at least purgatory/arch/i386/entry32-16-debug.S 
(along with other cases).

Perhaps pristine-tar could use an enhancement to screen out duplicates 
from the upstream manifest, if only to prevent breakage - or perhaps to 
warn the user.

  -Mike
   isely@pobox.com
   isely@isely.net

-- 

Mike Isely
isely @ isely (dot) net
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