Re: [PATCH 1/9] refs: Introduce pseudoref and per-worktree ref concepts

> Add glossary entries for both concepts.
>
> Pseudorefs and per-worktree refs do not yet have special handling,
> because the files refs backend already handles them correctly.  Later,
> we will make the LMDB backend call out to the files backend to handle
> per-worktree refs.
>
> Signed-off-by: David Turner <dturner@twopensource.com>
> ---
> Documentation/glossary-content.txt | 17 +++++++++++++++++
> refs.c                             | 23 +++++++++++++++++++++++
> refs.h                             |  2 ++
> 3 files changed, 42 insertions(+)
>
> diff --git a/Documentation/glossary-content.txt 
> b/Documentation/glossary-content.txt
> index ab18f4b..d04819e 100644
> --- a/Documentation/glossary-content.txt
> +++ b/Documentation/glossary-content.txt
> @@ -411,6 +411,23 @@ exclude;;
>  core Git. Porcelains expose more of a <<def_SCM,SCM>>
>  interface than the <<def_plumbing,plumbing>>.
>
> +[[def_per_worktree_ref]]per-worktree ref::
> + Refs that are per-<<def_worktree,worktree>>, rather than
> + global.  This is presently only <<def_HEAD,HEAD>>, but might
> + later include other unsuual refs.

> + a newline, and optionally some additional data.  `MERGE_HEAD`
> + and `CHERRY_PICK_HEAD` are examples.  Unlike
> + <<def_per_worktree_ref,per-worktree refs>>, these files cannot
> + be symbolic refs, and never not have reflogs.  They also
> + cannot be updated through the normal ref update machinery.
> + Instead, they are updated by directly writing to the files.
> + However, they can be read as if they were refs, so `git
> + rev-parse MERGE_HEAD` will work.
> +
> [[def_pull]]pull::
>  Pulling a <<def_branch,branch>> means to <<def_fetch,fetch>> it and
>  <<def_merge,merge>> it.  See also linkgit:git-pull[1].