make git fsck batch-capable

Git/Fsck.hs

@@ -16,6 +16,7 @@ import Git
 import Git.Command
 import Git.Sha
 import Git.CatFile
+import Utility.Batch
 
 import qualified Data.Set as S
 
@@ -31,17 +32,25 @@ type MissingObjects = S.Set Sha
  - to be a git sha. Not all such shas are of broken objects, so ask git
  - to try to cat the object, and see if it fails.
  -}
-findBroken :: Repo -> IO (Maybe MissingObjects)
-findBroken r = do
-	(output, fsckok) <- processTranscript "git" (toCommand $ fsckParams r) Nothing
+findBroken :: Bool -> Repo -> IO (Maybe MissingObjects)
+findBroken batchmode r = do
+	(output, fsckok) <- processTranscript command' (toCommand params') Nothing
 	let objs = parseFsckOutput output
 	badobjs <- findMissing objs r
 	if S.null badobjs && not fsckok
 		then return Nothing
 		else return $ Just badobjs
+  where
+	(command, params) = ("git", fsckParams r)
+	(command', params')
+		| batchmode = toBatchCommand (command, params)
+		| otherwise = (command, params)
 
 {- Finds objects that are missing from the git repsitory, or are corrupt.
- - Note that catting a corrupt object will cause cat-file to crash. -}
+ -
+ - Note that catting a corrupt object will cause cat-file to crash;
+ - this is detected and it's restarted.
+ -}
 findMissing :: [Sha] -> Repo -> IO MissingObjects
 findMissing objs r = go objs [] =<< start
   where

Git/RecoverRepository.hs

@@ -36,22 +36,22 @@ import qualified Data.ByteString.Lazy as L
 import System.Log.Logger
 import Data.Tuple.Utils
 
-{- Finds and removes corrupt objects from the repository, returning a list
- - of all such objects, which need to be found elsewhere to finish
- - recovery.
+{- Given a set of bad objects found by git fsck, removes all
+ - corrupt objects, and returns a list of missing objects,
+ - which need to be found elsewhere to finish recovery.
  -
- - Strategy: Run git fsck, remove objects it identifies as corrupt,
- - and repeat until git fsck finds no new objects.
+ - Since git fsck may crash on corrupt objects, and so not
+ - report the full set of corrupt or missing objects,
+ - this removes corrupt objects, and re-runs fsck, until it
+ - stabalizes.
  -
  - To remove corrupt objects, unpack all packs, and remove the packs
  - (to handle corrupt packs), and remove loose object files.
  -}
-cleanCorruptObjects :: Repo -> IO MissingObjects
-cleanCorruptObjects r = do
-	notice "Running git fsck ..."
-	check =<< findBroken r
+cleanCorruptObjects :: Maybe MissingObjects -> Repo -> IO MissingObjects
+cleanCorruptObjects mmissing r = check mmissing
   where
-  	check Nothing = do
+	check Nothing = do
 		notice "git fsck found a problem but no specific broken objects. Perhaps a corrupt pack file?"
 		ifM (explodePacks r)
 			( retry S.empty
@@ -72,7 +72,7 @@ cleanCorruptObjects r = do
 				else return bad
 	retry oldbad = do
 		notice "Re-running git fsck to see if it finds more problems."
-		v <- findBroken r
+		v <- findBroken False r
 		case v of
 			Nothing -> error $ unwords
 				[ "git fsck found a problem, which was not corrected after removing"