init: Fix a reversion that broke initialization on systems that need to use pid locking

This brings back .git/annex/misctmp, but only for init. If an init
is interrupted while probing using that temp directory, the files it left
will get deleted 1 week later by a subsequent git-annex run.

Annex/Init.hs

@@ -166,7 +166,7 @@ isInitialized = maybe Annex.Branch.hasSibling (const $ return True) =<< getVersi
 {- A crippled filesystem is one that does not allow making symlinks,
  - or removing write access from files. -}
 probeCrippledFileSystem :: Annex Bool
-probeCrippledFileSystem = withOtherTmp $ \tmp -> do
+probeCrippledFileSystem = withEventuallyCleanedOtherTmp $ \tmp -> do
 	(r, warnings) <- liftIO $ probeCrippledFileSystem' tmp
 	mapM_ warning warnings
 	return r
@@ -229,7 +229,7 @@ probeLockSupport = do
 #ifdef mingw32_HOST_OS
 	return True
 #else
-	withOtherTmp $ \tmp -> do
+	withEventuallyCleanedOtherTmp $ \tmp -> do
 		let f = tmp </> "lockprobe"
 		mode <- annexFileMode
 		liftIO $ do
@@ -247,7 +247,7 @@ probeFifoSupport = do
 #ifdef mingw32_HOST_OS
 	return False
 #else
-	withOtherTmp $ \tmp -> do
+	withEventuallyCleanedOtherTmp $ \tmp -> do
 		let f = tmp </> "gaprobe"
 		let f2 = tmp </> "gaprobe2"
 		liftIO $ do

Annex/Locations.hs

@@ -266,7 +266,8 @@ gitAnnexTmpOtherDir r = addTrailingPathSeparator $ gitAnnexDir r </> "othertmp"
 gitAnnexTmpOtherLock :: Git.Repo -> FilePath
 gitAnnexTmpOtherLock r = gitAnnexDir r </> "othertmp.lck"
 
-{- Tmp directory used by old versions of git-annex. -}
+{- .git/annex/misctmp/ was used by old versions of git-annex and is still
+ - used during initialization -}
 gitAnnexTmpOtherDirOld :: Git.Repo -> FilePath
 gitAnnexTmpOtherDirOld r = addTrailingPathSeparator $ gitAnnexDir r </> "misctmp"
 

Annex/Tmp.hs

@@ -7,9 +7,8 @@
 
 module Annex.Tmp where
 
-import Common
-import Annex
-import Annex.Locations
+import Annex.Common
+import qualified Annex
 import Annex.LockFile
 import Annex.Perms
 import Types.CleanupActions
@@ -24,13 +23,30 @@ import Data.Time.Clock.POSIX
 -- any time.
 withOtherTmp :: (FilePath -> Annex a) -> Annex a
 withOtherTmp a = do
-	addCleanup OtherTmpCleanup cleanupOtherTmp
+	Annex.addCleanup OtherTmpCleanup cleanupOtherTmp
 	tmpdir <- fromRepo gitAnnexTmpOtherDir
 	tmplck <- fromRepo gitAnnexTmpOtherLock
 	withSharedLock (const tmplck) $ do
 		void $ createAnnexDirectory tmpdir
 		a tmpdir
 
+-- | This uses an alternate temp directory. The action should normally
+-- clean up whatever files it writes there, but if it leaves files
+-- there (perhaps due to being interrupted), the files will be eventually
+-- cleaned up by another git-annex process (after they're a week old).
+--
+-- Unlike withOtherTmp, this does not rely on locking working.
+-- Its main use is in situations where the state of lockfile is not
+-- determined yet, eg during initialization.
+withEventuallyCleanedOtherTmp :: (FilePath -> Annex a) -> Annex a
+withEventuallyCleanedOtherTmp = bracket setup cleanup
+  where
+	setup = do
+		tmpdir <- fromRepo gitAnnexTmpOtherDirOld
+		void $ createAnnexDirectory tmpdir
+		return tmpdir
+	cleanup = liftIO . void . tryIO . removeDirectory 
+
 -- | Cleans up any tmp files that were left by a previous
 -- git-annex process that got interrupted or failed to clean up after
 -- itself for some other reason.
@@ -42,8 +58,6 @@ cleanupOtherTmp = do
 	void $ tryIO $ tryExclusiveLock (const tmplck) $ do
 		tmpdir <- fromRepo gitAnnexTmpOtherDir
 		void $ liftIO $ tryIO $ removeDirectoryRecursive tmpdir
-		-- This is only to clean up cruft left by old versions of
-		-- git-annex; it can be removed eventually.
 		oldtmp <- fromRepo gitAnnexTmpOtherDirOld
 		liftIO $ mapM_ cleanold =<< dirContentsRecursive oldtmp
 		liftIO $ void $ tryIO $ removeDirectory oldtmp -- when empty