Wrote nice pure transition calculator, and ugly code to stage its results
into the git-annex branch. Also had to split up several Log modules
that Annex.Branch needed to use, but that themselves used Annex.Branch.
The transition calculator is limited to looking at and changing one file at
a time. While this made the implementation relatively easy, it precludes
transitions that do stuff like deleting old url log files for keys that are
being removed because they are no longer present anywhere.
/!\ It is to be noted that revoking a key does NOT necessarily prevent
the owner of its private part from accessing data on the remote /!\
The only sound use of `keyid-=` is probably to replace a (sub-)key by
another, where the private part of both is owned by the same
person/entity:
git annex enableremote myremote keyid-=2512E3C7 keyid+=788A3F4C
Reference: http://git-annex.branchable.com/bugs/Using_a_revoked_GPG_key/
* Other change introduced by this patch:
New keys now need to be added with option `keyid+=`, and the scheme
specified (upon initremote only) with `encryption=`. The motivation for
this change is to open for new schemes, e.g., strict asymmetric
encryption.
git annex initremote myremote encryption=hybrid keyid=2512E3C7
git annex enableremote myremote keyid+=788A3F4C
Works, more or less. --dead is not implemented, and so far a new branch
is made, but keys no longer present anywhere are not scrubbed.
git annex sync fails to push the synced/git-annex branch after a forget,
because it's not a fast-forward of the existing synced branch. Could be
fixed by making git-annex sync use assistant-style sync branches.