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

On Wed, Aug 28, 2013 at 9:58 AM, Nicolas Pitre [off-list ref] wrote:

quoted

But what if we store
appended objects in OBJ_REF_DELTA format where base ref is empty
tree/commit and cached by sha1_file.c?

I don't follow you here.  Missing objects need to be added to the pack,
they can't be cached anywhere.

I use ref-delta as an alternate escape hatch to store missing commits
and trees in unparsed format. In order to do that, I need a base ref
SHA-1 and we can create and store SHA-1 of empty commit and emptry
tree in sha1_file.c (because empty commit is not in a valid format and
can't be parsed and stored in v3). So the result pack is still "thin"
but it should only lack at most two objects: empty commit and empty
tree. Thinking again this is much uglier than escape hatches to v3
tables..
-- 
Duy