better layout

And a theoretical fix to branchstate cache invalidation, but not a bug
that could actually happen.

Annex/Branch.hs

@@ -121,9 +121,7 @@ commit message = do
 {- Ensures that the branch is up-to-date; should be called before
  - data is read from it. Runs only once per git-annex run. -}
 update :: Annex ()
-update = do
-	state <- getState
-	unless (branchUpdated state) $ do
+update = onceonly $ do
 	-- check what needs updating before taking the lock
 	fs <- getJournalFiles
 	c <- filterM changedbranch =<< siblingBranches
@@ -154,7 +152,6 @@ update = do
 			liftIO $ Git.UnionMerge.merge_index g branches
 		liftIO $ Git.commit g "update" fullname (nub $ fullname:refs)
 		invalidateCache
-		Annex.changeState $ \s -> s { Annex.branchstate = state { branchUpdated = True } }
 	where
 		changedbranch (_, branch) = do
 			g <- gitRepo
@@ -166,6 +163,14 @@ update = do
 				Params "--oneline -n1"
 				]
 			return $ not $ L.null diffs
+		onceonly a = unlessM (branchUpdated <$> getState) $ do
+			r <- a
+			Annex.changeState setupdated
+			return r
+		setupdated s = s { Annex.branchstate = new }
+			where
+				new = old { branchUpdated = True }
+				old = Annex.branchstate s
 
 {- Checks if a git ref exists. -}
 refExists :: GitRef -> Annex Bool