non-pristine sources under pool/

[Magnus Damm <damm@opensource.se>]

Hi all,

I'm working on a free XML-based building system. The goal is to cross-compile
sources with description files for each source project. The system should
be more flexible than the .dsc-files that debian use. I intend to use it
for embedded systems.

Anyway, I thought of using the Sources.gz-file together with the pool/-
directory for getting sources from mirrors.

One of my first attempts except linux, binutils, gcc and glibc is to compile 
bash. But I got a bit confused about the non-pristine sources found under pool/.

This post tells me what I though the idea was.
http://lists.debian.org/debian-mentors/1999/debian-mentors-199901/msg00148.html
But the post is quite old, so things might have changed.

This is a snippet of my XML file which describes the file 
that is located on a gnu mirror.

<file>
   <name>bash-2.05b.tar.gz</name>
   <size>1956216</size>
   <md5>5238251b4926d778dfe162f6ce729733</md5>
</file>

This file,

http://ftp.sunet.se/pub/Linux/distributions/debian/pool/main/b/bash/bash_2.05b-3.dsc

tells me:

 95e836e7adf20a3cbc429609b99ff024 1944574 bash_2.05b.orig.tar.gz

As you can see the size and the md5-sum differs. 

I unpacked both tar.gz files and compared them.
They are the same (compared with diff) except for the directory they create.

What is going on? Why is not the original file used?

Sorry if this is a common question. 

Thanks /

Magnus Damm,
Öpensöurce AB

PS: Please CC me, I'm not subscribed to this list.