support pointer files

Backend.lookupFile is changed to always fall back to catKey when
operating on a file that's not a symlink.

catKey is changed to understand pointer files, as well as annex symlinks.

Before, catKey needed a file mode witness, to be sure it was looking at a
symlink. That was complicated stuff. Now, it doesn't actually care if a
file in git is a symlink or not; in either case asking git for the content
of the file will get the pointer to the key.

This does mean that git-annex will treat a link
foo -> WORM--bar as a git-annex file, and also treats
a regular file containing annex/objects/WORM--bar as a git-annex file.

Calling catKey could make git-annex commands need to do more work than
before. This would especially be the case if a repo contained many regular
files, and only a few annexed files, as now git-annex will need to ask
git about the contents of the regular files.

1 files changed, 4 insertions, 10 deletions

diff --git a/Backend.hs b/Backend.hs
index 922d0c2a7..28f83c7e0 100644
--- a/Backend.hs
+++ b/Backend.hs
@@ -26,7 +26,6 @@ import Annex.Link
 import Types.Key
 import Types.KeySource
 import qualified Types.Backend as B
-import Config
 
 -- When adding a new backend, import it here and add it to the list.
 import qualified Backend.Hash
@@ -81,22 +80,17 @@ genKey' (b:bs) source = do
 {- Looks up the key corresponding to an annexed file,
  - by examining what the file links to.
  -
- - In direct mode, there is often no link on disk, in which case
- - the symlink is looked up in git instead. However, a real link
- - on disk still takes precedence over what was committed to git in direct
- - mode.
+ - An unlocked file will not have a link on disk, so fall back to
+ - looking for a pointer to a key in git.
  -}
 lookupFile :: FilePath -> Annex (Maybe Key)
 lookupFile file = do
 	mkey <- isAnnexLink file
 	case mkey of
 		Just key -> makeret key
-		Nothing -> ifM isDirect
-			( maybe (return Nothing) makeret =<< catKeyFile file
-			, return Nothing
-			)
+		Nothing -> maybe (return Nothing) makeret =<< catKeyFile file
   where
-	makeret k = return $ Just k
+	makeret = return . Just
 
 getBackend :: FilePath -> Key -> Annex (Maybe Backend)
 getBackend file k = let bname = keyBackendName k in