[[!comment format=mdwn
 username="joey"
 subject="""comment 2"""
 date="2016-10-13T17:27:36Z"
 content="""
For a `git annex merge --remotes` to be useful, there would need to be a
config to disable the automatic merging of git-annex branches, which all
git-annex commands do when they notice it needs to be done.
So, this needs to be a git config and not a switch, so it can also
control the automatic git-annex branch merging.

Using remote.name.annex-ignore as the config does not make sense on second
look, because that gets set automatically when the remote is on eg
github.

Using remote.name.annex-sync=false as the config makes some sense, although
as noted above, that prevents `git annex sync` from fetching from the
remote already, so unless `git pull` is run manually, the existing config
should suffice.

To implement that, git-annex would have to parse the remote.name.fetch
config in order to tell what name a remote's git-annex branch is fetched
to. I am reluctant to do this for several reasons:

* The syntax of remote.name.fetch is only documented by example. It's
  not clear what's supposed to be done if eg, the `*` appears twice
  in a branch name or different numbers of times on the left and right hand
  sides.

* Two remotes can have remote.name.fetch set such that the same remote
  tracking branch is locally used for fetches from both remotes. So
  git-annex would not know if such a branch should be synced or not.

* remote.name.fetch can be overridden when using git fetch or git pull at
  the command line, so again git-annex can't know for sure what remote a
  given tracking branch came from.

Four approaches that could work:

1. Add a config that is a list of remote tracking branches, and
   make `git annex merge` and the automatic git-annex branch merging merge
   only those tracking branches. For example, 
   `annex.allowmerge=refs/remotes/origin/git-annex refs/remotes/origin/master`

   Doable, but it seems this would be an annoying list to maintain,
   especially when new branches are made.

2. Embed some information in a branch that can be looked at to determine
   that git-annex should not auto-merge this branch. Note that this would
   need to be done for both the git-annex branch and the regular branch.
   The latter seems particularly hard to do.

3. Configure remote.name.fetch so that the remote git-annex branch is
   either not fetched, or fetched to a tracking branch that does not end
   in `/git-annex`. I think this is possible to do, but due to the lack of
   documentation for that config, it would take some experimentation to
   find how to do it. This would prevent the automatic merging of that
   branch by git-annex. 
   
   And if you make the remote master branch be
   fetched to eg refs/remotes/name/master/nomerge then `git annex merge`
   won't merge that into master.

4. Prevent adding a remote to a repository if that remote contains private
   information that you don't want to get merged into the local repository.
   This still seems like the best solution to me; if the information is
   private it should not be possible to fetch it from the remote.
"""]]