Re: [PATCH 2/2] git-fetch: use fetch--tool pick-rref to avoid local fetch from alternate

Junio C Hamano [off-list ref] wrote:

+			# This will barf when $theirs reach an object that
+			# we do not have in our repository.  Otherwise,
+			# we already have everything the fetch would bring in.
+			git-rev-list --objects $theirs --not --all 2>/dev/null

OK, I must be missing something here.

That rev-list is going to print out the SHA-1s for the objects we
would have copied, but didn't, isn't it?  So fetch--tool native-store
is going to get a whole lot of SHA-1s it doesn't want to see, right?

Otherwise this is a nice trick.  It doesn't assure us that after the
fetch those objects are still in the alternate.  Meaning someone
could run prune in the alternate between the rev-list and the
native-store, and whack these objects.  Given how small of a window
it is, and the improvements this brings to alternates, I say its
worth that small downside.  Just don't prune while fetching.  ;-)

-- 
Shawn.