[[!comment format=mdwn
 username="http://joeyh.name/"
 nickname="joey"
 subject="comment 5"
 date="2013-05-29T17:54:11Z"
 content="""
I started to make a branch with the change I suggested, but then I had another idea.

The checkpresent hook can return either True or, False, or fail with a message if it cannot successfully check the remote. Currently for glacier, when --trust-glacier is not set, it always returns False. Crucially, in the case when a file is in glacier, this is telling git-annex it's not there, so copy re-uploads it. What if it instead, when the glacier inventory is missing a file, it returns False. And when the glacier inventory has a file, unless --trust-glacier is set, it *fails*.

The result would be:

* `git annex copy --to glacier` would only send things not listed in inventory. If a file is listed in the inventory, `copy`
  would complain that --trust-glacier` is not set, and not re-upload the file.
* `git annex drop` would only trust that glacier has a file when --trust-glacier is set. Behavior unchanged.
* `git annex move --to glacier`, when the file is not listed in inventory, would send the file, and delete it locally. Behavior unchanged.
* `git annex move --to glacier`, when the file is listed in inventory, would only trust that glacier has the file when --trust-glacier is set
* `git annex copy --from glacier` / `git annex get`, when the file is located in glacier, would trust the location log, and attempt to get the file from glacier.

This seems like it should do the right thing in all cases, but I have not tested it. I've pushed a `glacier` branch with this change.
"""]]