Re: RFC: Allow missing objects during packing

"Shawn O. Pearce" [off-list ref] writes:

If we are building a thin pack and one of the base objects we would
consider for deltification is missing its OK, the other side already
has that base object.  We may be able to get a delta from another
object, or we can simply send the new object whole (no delta).

This allows a shallow clone which may have only commits and trees
(but only partial blobs) to generate a pack for a fetch client,
so the shallow clone only needs to contain objects that are not
in the common base.

I'd queue this to 'pu' (or 'next' if you want, but that amounts to about
the same thing as we will be rebuilding 'next' soon after 1.6.0 ships),
but this would probably be better demonstrated with a test script that
demonstrates in what workflow this would be useful.