Re: [PATCH 6/7] read-cache: refuse to create index referring to external objects

> Duy Nguyen <pclouds@gmail.com> writes:
>
>> On Sat, Jan 26, 2013 at 2:00 AM, Junio C Hamano <gitster@pobox.com> wrote:
>>> This is not a tangent, but if you want to go this "forbid making our
>>> repository depend on objects we do not have but we know about after
>>> we peek submodule odb" route [*1*], write_sha1_file() needs to be
>>> told about has_sha1_file_proper().  We may "git add" a new blob in
>>> the superproject, the blob may not yet exist in *our* repository,
>>> but may happen to already exist in the submodue odb.  In such a
>>> case, write_sha1_file() has to write that blob in our repository,
>>> without the existing has_sha1_file() check bypassing it.  Otherwise
>>> our attempt to create a tree that contains that blob will fail,
>>> saying that the blob only seems to exist to us via submodule odb but
>>> not in our repository.
>>
>> Another thing needs to be done for this to work. The current reading
>
> For *what* to work???

> I think the performance consideration is the
> only thing that should drive the read-order; correctness should not
> be affected.
>
>> order is packs first, loose objects next. If we create a local loose
>> duplicate of an alternate packed object, our local version will never
>> be read. Regardless the submodule odb issue, I think we should prefer
>> reading local loose objects over alternate packed ones.