Slight inconsistency between ref delete commands.

Slight inconsistency between ref delete commands.

[Sergei Organov]

Hello,

Was writing conversion script from CVS to git for my repo and noticed
slight inconsistency in git-tag, git-branch, and git-update-ref behavior:

$ git --version
git version 1.9.3
$ git tag -d && echo success
success
$ git branch -d && echo success
fatal: branch name required
$ git update-ref -d && echo success
usage: git update-ref [options] -d <refname> [<oldval>]
   or: git update-ref [options]    <refname> <newval> [<oldval>]
   or: git update-ref [options] --stdin [-z]

    -m <reason>           reason of the update
    -d                    delete the reference
    --no-deref            update <refname> not the one it points to
    -z                    stdin has NUL-terminated arguments
    --stdin               read updates from stdin


Noticed when used xargs without -r switch, like this:

git for-each-ref --format="%(refname)" "refs/tags/*-merge" | xargs -n 1 git update-ref -d

-- Sergey.

Re: Slight inconsistency between ref delete commands.

[Jeff King]

On Wed, May 21, 2014 at 02:35:46PM +0400, Sergei Organov wrote:

> Was writing conversion script from CVS to git for my repo and noticed
> slight inconsistency in git-tag, git-branch, and git-update-ref behavior:
> 
> $ git --version
> git version 1.9.3
> $ git tag -d && echo success
> success

This makes sense to me. "tag -d" takes zero or more tags and deletes
them.

> $ git branch -d && echo success
> fatal: branch name required

Here I think "branch -d" is being overly picky. It should behave the
same as tag. I'd welcome a patch for that.

> $ git update-ref -d && echo success

Here we cannot do the same "zero or more" behavior, because of:

> usage: git update-ref [options] -d <refname> [<oldval>]

...we need to be able to take an optional "<oldval>" for each argument.

> Noticed when used xargs without -r switch, like this:
> 
> git for-each-ref --format="%(refname)" "refs/tags/*-merge" | xargs -n 1 git update-ref -d

I know this is a side note to the inconsistency you found, but it would
be nice to be able to do that with a single update-ref invocation. Not
only for simplicity, but also because it would be more efficient
(deleting a packed ref has to rewrite the whole packed-refs file; we can
get away with one rewrite if we know we are deleting multiple refs).

Recently-ish, update-ref learned a "--stdin" mode, which I think you
could use like:

  git for-each-ref --format='delete %(refname)' refs/tags/*-merge |
  git update-ref --stdin

-Peff