Re: [PATCH v3] nmbug: Add an 'init' command

[Michal Sojka <sojkam1@fel.cvut.cz>]

Hi Trevor,

On Út, říj 28 2014, W. Trevor King wrote:
> For folks that want to start versioning a new tag-space, instead of
> cloning one that someone else has already started.
>
> The empty-blob hash-object call avoids errors like:
>
>   $ nmbug commit
>   error: invalid object 100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 for
> 'tags/...'
>   fatal: git-write-tree: error building trees
>   'git HASH(0x9ef3eb8) write-tree' exited with nonzero value
>
> David Bremner suggested [1]:
>
>   $ git hash-object -w /dev/null
>
> instead of my Python version of:
>
>   $ git hash-object -w --stdin <&-
>
> but I expect that closing stdin is more portable than the /dev/null
> path (which doesn't exist on Windows, for example).
>
> [1]: id:87y4vu6uvf.fsf@maritornes.cs.unb.ca
>      http://thread.gmane.org/gmane.mail.notmuch.general/18626/focus=18720
> ---
> The only change since v2 [1] is a commit-message tweak:
>
> * Mention Windows as an OS with stdin but no /dev/null [2].
>
> Cheers,
> Trevor
>
> [1]: id:eaa9cf1cb3c00c591dc675c0f314ca31909ff74c.1412965476.git.wking@tremily.us
>      http://thread.gmane.org/gmane.mail.notmuch.general/19289
> [2]: id:20141011071000.GB10926@odin.tremily.us
>      http://article.gmane.org/gmane.mail.notmuch.general/19294
>
>  devel/nmbug/nmbug | 24 ++++++++++++++++++++++++
>  1 file changed, 24 insertions(+)
>
> diff --git a/devel/nmbug/nmbug b/devel/nmbug/nmbug
> index 9402ead..23bac5c 100755
> --- a/devel/nmbug/nmbug
> +++ b/devel/nmbug/nmbug
> @@ -373,6 +373,29 @@ def fetch(remote=None):
>      _git(args=args, wait=True)
>  
>  
> +def init(remote=None):
> +    """
> +    Create an empty nmbug repository.
> +
> +    This wraps 'git init' with a few extra steps to support subsequent
> +    status and commit commands.
> +    """
> +    with _tempfile.TemporaryDirectory(prefix='nmbug-init.') as workdir:
> +        _spawn(
> +            args=['git', 'init', '--separate-git-dir', NMBGIT, workdir],
> +            wait=True)
> +        _git(args=['config', '--unset', 'core.worktree'], wait=True)
> +        _git(args=['config', 'core.bare', 'true'], wait=True)

Why do you create a non-bare repository and then make it bare? Before I
discovered this patch, I created the nmbug repository by hand and it was
possible to do it with bare repo from beginning. The following code
seems to work and is a bit simpler:

def init(remote=None):
    """
    Create an empty nmbug repository.

    This wraps 'git init' with a few extra steps to support subsequent
    status and commit commands.
    """
    _spawn(
        args=['git', '--git-dir', NMBGIT, 'init', '--bare'],
        wait=True)
    # create an empty blob (e69de29bb2d1d6434b8b29ae775ad8c2e48c5391)
    _git(args=['hash-object', '-w', '--stdin'], input='', wait=True)
    _git(
        args=[
            'commit', '--allow-empty', '-m', 'Start a new nmbug repository'
            ],
        additional_env={'GIT_WORK_TREE': NMBGIT},
        wait=True)

Note that in the initial commit I set the work tree to NMBGIT. This is
because 'git commit' needs some work tree, but in our case it doesn't
matter which one because the commit is empty.

-Michal


> +        # create an empty blob (e69de29bb2d1d6434b8b29ae775ad8c2e48c5391)
> +        _git(args=['hash-object', '-w', '--stdin'], input='', wait=True)
> +        _git(
> +            args=[
> +                'commit', '--allow-empty', '-m', 'Start a new nmbug repository'
> +                ],
> +            additional_env={'GIT_WORK_TREE': workdir},
> +            wait=True)
> +
> +
>  def checkout():
>      """
>      Update the notmuch database from Git.
> @@ -703,6 +726,7 @@ if __name__ == '__main__':
>              'clone',
>              'commit',
>              'fetch',
> +            'init',
>              'log',
>              'merge',
>              'pull',
> -- 
> 2.1.0.60.g85f0837
>
> _______________________________________________
> notmuch mailing list
> notmuch@notmuchmail.org
> http://notmuchmail.org/mailman/listinfo/notmuch