Work around git bug in handling of relative path to GIT_INDEX_FILE when in a subdirectory of the repository.

This affected git annex view. It turns out that some other places
that use GIT_INDEX_FILE were already working around the bug. I removed the
workaround from Annex.Branch since the new workaround will do.

Annex/Branch.hs

@@ -367,7 +367,7 @@ withIndex :: Annex a -> Annex a
 withIndex = withIndex' False
 withIndex' :: Bool -> Annex a -> Annex a
 withIndex' bootstrapping a = do
-	f <- liftIO . absPath =<< fromRepo gitAnnexIndex
+	f <- fromRepo gitAnnexIndex
 	withIndexFile f $ do
 		checkIndexOnce $ unlessM (liftIO $ doesFileExist f) $ do
 			unless bootstrapping create

Annex/GitOverlay.hs

@@ -17,9 +17,13 @@ import qualified Annex
 
 {- Runs an action using a different git index file. -}
 withIndexFile :: FilePath -> Annex a -> Annex a
-withIndexFile f = withAltRepo
+withIndexFile f a = do
-	(\g -> addGitEnv g "GIT_INDEX_FILE" f)
+	-- Workaround http://thread.gmane.org/gmane.comp.version-control.git/294880
+	absf <- liftIO $ absPath f
+	withAltRepo
+		(\g -> addGitEnv g "GIT_INDEX_FILE" absf)
 		(\g g' -> g' { gitEnv = gitEnv g })
+		a
 
 {- Runs an action using a different git work tree.
  -

Git/Index.hs

@@ -24,7 +24,9 @@ indexEnv = "GIT_INDEX_FILE"
 override :: FilePath -> IO (IO ())
 override index = do
 	res <- getEnv var
-	setEnv var index True
+	-- Workaround http://thread.gmane.org/gmane.comp.version-control.git/294880
+	absindex <- absPath index
+	setEnv var absindex True
 	return $ reset res
   where
 	var = "GIT_INDEX_FILE"

debian/changelog

@@ -15,6 +15,8 @@ git-annex (6.20160512) UNRELEASED; urgency=medium
     thing)
   * adjust: Add --fix adjustment, which is useful when the git directory
     is in a nonstandard place.
+  * Work around git bug in handling of relative path to GIT_INDEX_FILE
+    when in a subdirectory of the repository. This affected git annex view.
 
  -- Joey Hess <id@joeyh.name>  Wed, 11 May 2016 16:08:38 -0400