Re: Multiple fetches when unshallowing a shallow clone

[Jeff King <peff@peff.net>]

On Fri, Dec 04, 2015 at 12:46:59PM -0800, Stefan Beller wrote:

> On Mon, Nov 30, 2015 at 11:35 AM, Jason Paller-Rzepka
> <jasonpr@google.com> wrote:
> > Hi all,
> >
> > Would anyone be willing to help me understand some shallow-clone
> > behavior?  (I found a bug in Dulwich, and I'm looking for some context
> > so I can determine how to fix it.)
> >
> > I learned that cgit sometimes performs two fetches for a `git fetch
> > --unshallow`: one with depth 'infinity', and a subsequent one with
> > depth zero.
> 
> Is there a condition to trigger this 'sometimes' ?
> 
> I just tried reproducing via
> $ GIT_TRACE=1 git fetch --unshallow
> 
> and could not see a second fetch, but only a
> fetch-pack with --depth=2147483647

This seems to reproduce consistently for me:

  $ git clone --depth=1 git://github.com/git/git
  Cloning into 'git'...
  remote: Counting objects: 2925, done.
  remote: Compressing objects: 100% (2602/2602), done.
  remote: Total 2925 (delta 230), reused 2329 (delta 206), pack-reused 0
  Receiving objects: 100% (2925/2925), 6.17 MiB | 10.80 MiB/s, done.
  Resolving deltas: 100% (230/230), done.

  $ cd git
  $ git fetch --unshallow
  remote: Counting objects: 185430, done.
  remote: Compressing objects: 100% (46933/46933), done.
  remote: Total 185430 (delta 140505), reused 181589 (delta 136694), pack-reused 0
  Receiving objects: 100% (185430/185430), 52.80 MiB | 10.84 MiB/s, done.
  Resolving deltas: 100% (140505/140505), completed with 1784 local objects.
  remote: Counting objects: 579, done.
  remote: Compressing objects: 100% (579/579), done.
  remote: Total 579 (delta 0), reused 579 (delta 0), pack-reused 0
  Receiving objects: 100% (579/579), 266.85 KiB | 0 bytes/s, done.
  [... fetch output ...]

That looks like two packs being received for the --unshallow case.

-Peff