It doesn't matter if the object is present or not, gitAnnexLink should
always yield the same symlink target.
This is an optimisation; no behavior should be changed.
Seen for example, a newly checked out git submodule. In this case,
.git/HEAD is a raw sha, rather than the usual reference to a ref.
Removed currentSha in passing, since it was a more roundabout way of
doing what headSha does, and headSha is more robust.
The fix is to stop using w82s, which does not properly reconstitute unicode
strings. Instrad, use utf8 bytestring to get the [Word8] to base64. This
passes unicode through perfectly, including any invalid filesystem encoded
characters.
Note that toB64 / fromB64 are also used for creds and cipher
embedding. It would be unfortunate if this change broke those uses.
For cipher embedding, note that ciphers can contain arbitrary bytes (should
really be using ByteString.Char8 there). Testing indicated it's not safe to
use the new fromB64 there; I think that characters were incorrectly
combined.
For credpair embedding, the username or password could contain unicode.
Before, that unicode would fail to round-trip through the b64.
So, I guess this is not going to break any embedded creds that worked
before.
This bug may have affected some creds before, and if so,
this change will not fix old ones, but should fix new ones at least.
Seems to work, but still experimental until it's been tested more.
When repositories are on filesystems not supporting symlinks, the .git dir
symlink trick cannot be used. Since we're going to be in direct mode
anyway, the .git dir symlink is not strictly needed.
However, I have not fixed the code that creates new annex symlinks to
handle this case -- the committed symlinks will be wrong.
git annex sync happens to currently fail in a submodule using direct mode,
because there's no HEAD ref. That also needs to be dealt with to get
this fully working in crippled filesystems.
Leaving http://github.com/datalad/datalad/issues/44 open until these issues
are dealt with.
Avoids a warning message from git when HEAD doesn't exist. Which it won't
when eg, git-annex is used in a submodule just cloned with
git clone --recursive. In this case, a specific ref is checked out and
there's no HEAD yet.
The code already returned Nothing in this case, so no behavior change other
than not showing the warning. And git-annex operates fine in this
situation.
