Re: heads-up: git-index-pack in "next" is broken

[Linus Torvalds <torvalds@osdl.org>]

On Tue, 17 Oct 2006, Nicolas Pitre wrote:
> 
> Because offsets into packs are expressed as unsigned long everywhere 
> else (except in the current pack index on-disk format).

Until your work, that "unsigned long" was totally just an internal thing 
that didn't actually bleed into anything else.

> > For some structure like this, it sounds positively wrong. Pack-files 
> > should be architecture-neutral, which means that they shouldn't depend on 
> > word-size, and they should be in some neutral byte-order.
> 
> But they do.  Please consider this code:

Right. The pack-file itself. But the code that actually _generates_ it 
mixes things in alarming ways.

> > In contrast, the new union introduced in "next" is just horrid. There's 
> > not even any way to know which member to use, except apparently that it 
> > expects that a SHA1 is never zero in the last 12 bytes. Which is probably 
> > true, but still - that's some ugly stuff.
> 
> This union should be looked at just like a sortable hash pointing to a 
> base object so that deltas with the same base object can be sorted 
> together.

.. and it sorts _differently_ on a big-endian vs little-endian thing, 
doesn't it?

So now the sort order depends on endianness and/or wordsize. That just 
sounds really really wrong.

			Linus