fix up commands that are trouble on bare repos

Most will just abort. init does a basic init and gives a command to
run elsewhere to finish it.

Command/DropUnused.hs

@@ -29,7 +29,7 @@ seek = [withStrings start]
 
 {- Drops unused content by number. -} 
 start :: CommandStartString
-start s = do
+start s = notBareRepo $ do
 	m <- readUnusedLog
 	case M.lookup s m of
 		Nothing -> return Nothing

Command/FromKey.hs

@@ -27,9 +27,8 @@ command = [Command "fromkey" paramPath seek
 seek :: [CommandSeek]
 seek = [withFilesMissing start]
 
-{- Adds a file pointing at a manually-specified key -}
 start :: CommandStartString
-start file = do
+start file = notBareRepo $ do
 	key <- cmdlineKey
 	inbackend <- Backend.hasKey key
 	unless inbackend $ error $

Command/Fsck.hs

@@ -27,7 +27,7 @@ seek :: [CommandSeek]
 seek = [withAttrFilesInGit "annex.numcopies" start]
 
 start :: CommandStartAttrFile
-start (file, attr) = isAnnexed file $ \(key, backend) -> do
+start (file, attr) = notBareRepo $ isAnnexed file $ \(key, backend) -> do
 	showStart "fsck" file
 	return $ Just $ perform key file backend numcopies
 	where

Command/Init.hs

@@ -41,11 +41,19 @@ perform :: String -> CommandPerform
 perform description = do
 	g <- Annex.gitRepo
 	u <- getUUID g
-	describeUUID u description
 	setVersion
-	liftIO $ gitAttributesWrite g
-	gitPreCommitHookWrite g
-	return $ Just cleanup
+	if Git.repoIsLocalBare g
+		then do
+			showLongNote $
+				"This is a bare repository, so its description cannot be committed.\n" ++
+				"To record the description, run this command in a clone of this repository:\n" ++
+				"   git annex describe " ++ (show u) ++ " '" ++ description ++ "'\n\n"
+			return $ Just $ return True
+		else do
+			describeUUID u description
+			liftIO $ gitAttributesWrite g
+			gitPreCommitHookWrite g
+			return $ Just cleanup
 
 cleanup :: CommandCleanup
 cleanup = do

Command/Unused.hs

@@ -32,7 +32,7 @@ seek = [withNothing start]
 
 {- Finds unused content in the annex. -} 
 start :: CommandStartNothing
-start = do
+start = notBareRepo $ do
 	showStart "unused" ""
 	return $ Just perform
 

debian/changelog

@@ -11,7 +11,8 @@ git-annex (0.22) UNRELEASED; urgency=low
   * New backends: SHA512 SHA384 SHA256 SHA224
   * fsck: Check for and repair location log damage.
   * Git annexes can now be attached to bare git repositories. Due to popular
-    demand.
+    demand. Both the local and remote host must have this version of git-annex
+    installed for it to work.
 
  -- Joey Hess <joeyh@debian.org>  Sun, 13 Feb 2011 00:48:02 -0400
 

doc/bare_repositories.mdwn

@@ -1,13 +1,13 @@
+**This is still an experimental feature!** Use with caution.
+
 Due to popular demand, git-annex can now be used with bare repositories.
 
 So, for example, you can stash a file away in your
 repos's origin: `git annex move mybigfile --to origin`
 
 Of course, for that to work, the bare repository has to be on a system with
-[[git-annex-shell]] installed. If "origin" is on gitweb, you still can't
-use git-annex to there.
-
-**This is still an experimental feature!** 
+[[git-annex-shell]] installed. If "origin" is on GitWeb, you still can't
+use git-annex to store stuff there.
 
 Known to work ok:
 
@@ -17,16 +17,15 @@ Known to work ok:
   that is being dropped.
 * `git annex get` can transfer data from a bare repository.
 
-There are a few caveats to keep in mind:
+There are a few caveats to keep in mind when using bare repositories:
 
 * `git annex init` can be run in a bare repository, but it cannot
   store the name you gave the repository in .git-annex/uuid.log (because
-  the bare repository has no such file to commit to).
-* `git annex fromkey` does something pointless in a bare repository.
-* `git annex fsck` cannot detect any problems in a bare repository.
-* `git annex unused` will think everything stored in a bare repository
-  is unused.
-* `git annex setkey` is a plumbing-level command, and using it manually
+  the bare repository has no such file to commit to). Instead, it will
+  tell you a command to run in some non-bare clone of the repository.
+* Some subcommands, like `fsck`, `trust`, `unused` and `fromkey`, 
+  cannot be run in a bare repository. Those subcommands will
+  refuse to do anything.
+* `git annex setkey` is a plumbing-level command; using it manually
   to add content to a bare repository is not recommended, since there
-  will be no record accessible by other repositories that the content
-  is stored there.
+  will be no record that the content is stored there.

doc/index.mdwn

@@ -54,6 +54,7 @@ files with git.
 * git-annex prevents accidental data loss by [[tracking copies|copies]]
   of your files
 * [[internals]]
+* [[bare_repositories]]
 * [[what git annex is not|not]]
 * git-annex is Free Software, licensed under the [[GPL]].