Re: [PATCH 00/23] Preliminary pack v4 support

Nicolas Pitre [off-list ref] writes:

On Tue, 27 Aug 2013, Junio C Hamano wrote:

quoted

Nicolas Pitre [off-list ref] writes:
... 

quoted

I'd like to preserve the author time stamps as they relate to where in
the world I was when the corresponding code was written.  You'll notice
I didn't work on the code in the same order as it is now presented.

We can also notice things like "From: user@machine.(none)" ;-)

Heh.

In any case, the "Date: " in-body header next to your "From: "
in-body header is your friend if you want to do the "where and when
did I work on this?"

quoted

quoted

Still open question: what to do with a thin pack.  Should we really
complete it with local objects upon reception, or were we only over
paranoid at the time we imposed this rule?

I do not think paranoia had much to do with it.  I am afraid that
allowing a delta in a pack to depend on a base in another pack means
that the former pack becomes unusable without the latter, which
would make object store management (e.g. partial repacking) a lot
more cumbersome, no?

That's what I'm wondering.  We already end up with a broken repository 
if the commit graph is spread across multiple packs and one of those 
pack is removed.  Having a delta base in a separate pack is not much 
different in that regard.

In practice, maybe, but I somehow find that it is more fundamental
breakage not to be able to reconstitute objects that a pack and its
index claims to have than missing an object that is referenced in
the reachability graph.

As you have "0-index" escape hatch for SHA-1 table, but no similar
escape hatch for the people's name table, I can see why it may be
cumbersome to fix a thin pack by only appending to a received
packfile and updating a few header fields, though.

So the rule could be that any kind of repacking must not carry over 
deltas with a non local base i.e. repack always produces delta 
references belonging to the same pack.