Bug in git 2.1.0 when cloning to directory with same name as repository

Bug in git 2.1.0 when cloning to directory with same name as repository

[Chris Salzberg]

I've found what looks like a bug wherein if you are using an ssh alias
for a git remote, and that remote has a dash in its name, and you
specify the target path as the name of the url itself, git complains
about refs not being valid packed references.

To reproduce, in git 2.1.0 and with a repository using ssh config and
which has a dash in the name, e.g.:

> git clone github:nixme/pry-nav "github:nixme/pry-nav"
Cloning into 'github:nixme/pry-nav'...
done.
  ror: internal error: refs/remotes/origin/master is not a valid
packed reference!
error: internal error: refs/tags/v0.0.1 is not a valid packed reference!
error: internal error: refs/tags/v0.0.2 is not a valid packed reference!
error: internal error: refs/tags/v0.0.3 is not a valid packed reference!
error: internal error: refs/tags/v0.0.4 is not a valid packed reference!
error: internal error: refs/tags/v0.1.0 is not a valid packed reference!
error: internal error: refs/tags/v0.2.0 is not a valid packed reference!
error: internal error: refs/tags/v0.2.1 is not a valid packed reference!
error: internal error: refs/tags/v0.2.2 is not a valid packed reference!
error: internal error: refs/tags/v0.2.3 is not a valid packed reference!
error: internal error: refs/tags/v0.2.4 is not a valid packed reference!
error: Trying to write ref refs/heads/master with nonexistent object
f0e17451f0bd508f408d4fdda97e3a131d11f696
fatal: Cannot update the ref 'HEAD'

The ssh config for github (not that it matters, but for completeness) is:

Host github
user git
hostname github.com

I have confirmed that if the repository url does not have a dash, this
works as expected. I have also downgraded to 2.0.4 and found that
again, this works as expected. Beyond this I have not narrowed the
scope.

For now, I've downgraded my version of git and so have not tested beyond this.

Chris Salzberg

Re: Bug in git 2.1.0 when cloning to directory with same name as repository

[Jeff King]

On Tue, Sep 23, 2014 at 04:49:55PM +0900, Chris Salzberg wrote:

> I've found what looks like a bug wherein if you are using an ssh alias
> for a git remote, and that remote has a dash in its name, and you
> specify the target path as the name of the url itself, git complains
> about refs not being valid packed references.
> 
> To reproduce, in git 2.1.0 and with a repository using ssh config and
> which has a dash in the name, e.g.:

Thanks for a reproduction recipe. I think we can make it simpler,
though. The problem seems to come when your destination directory is
identical to the remote URL. I saw similar failures with:

  git clone git@github.com:git/git git@github.com:git/git

and even:

  git clone https://github.com/git/git https://github.com/git/git

It bisects to f38aa83 (use local cloning if insteadOf makes a local URL,
2014-07-17) by Michael Barabanov (cc'd). That commit moved a call to
get_repo_path() much further down cmd_clone, after we have already
created the repo directory. As a result, we try to fetch objects from
the newly created directory, which of course has none (and because it's
local, we try to use "cp" instead of the git protocol. We don't notice
the error at transfer time, but rather later when trying to write out
the references).

I'm not sure of the simplest solution. I guess along the lines of one
of:

  1. Move the code back before the directory is created. Rather than
     using `remote_get` to apply insteadOf substitution as a side
     effect, make it possible to call into the insteadOf code directly.

  2. It might work to chdir() into the repo after creating it, though
     that probably creates its own problems with other relative paths
     (and I am not sure it would save us if you had a remote URL that
     looked like an absolute path).

-Peff