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