display new empty repos in maxsize table

A new repo that has no location log info yet, but has an entry in
uuid.log has 0 size, so make RepoSize aware of that.

Note that a new repo that does not yet appear in uuid.log will still not
be displayed.

When a remote is added but not synced with yet, it has no uuid.log
entry. If git-annex maxsize is used to configure that remote, it needs
to appear in the maxsize table, and the change to Command.MaxSize takes
care of that.

Annex/RepoSize.hs

@@ -126,7 +126,9 @@ diffBranchRepoSizes quiet oldsizemap oldbranchsha newbranchsha = do
 		newsizemap <- readpairs 100000 reader oldsizemap Nothing
 		liftIO $ wait feedtid
 		ifM (liftIO cleanup)
-			( return (newsizemap, newbranchsha)
+			( do
+				newsizemap' <- addemptyrepos newsizemap
+				return (newsizemap', newbranchsha)
 			, return (oldsizemap, oldbranchsha)
 			)
   where
@@ -156,3 +158,10 @@ diffBranchRepoSizes quiet oldsizemap oldbranchsha newbranchsha = do
 				readpairs n' reader sizemap' Nothing
 		Nothing -> return sizemap
 	parselog = maybe mempty (S.fromList . parseLoggedLocationsWithoutClusters)
+	
+	addemptyrepos newsizemap = do
+		knownuuids <- M.keys <$> uuidDescMap
+		return $ foldl'
+			(\m u -> M.insertWith (flip const) u (RepoSize 0) m)
+			newsizemap
+			knownuuids

Command/MaxSize.hs

@@ -76,9 +76,16 @@ sizeOverview o = do
 		descmap <- Remote.uuidDescriptions
 		deadset <- S.fromList <$> trustGet DeadTrusted
 		maxsizes <- getMaxSizes
-		reposizes <- flip M.withoutKeys deadset <$> getRepoSizes True
+		reposizes <- getRepoSizes True
+		-- Add repos too new and empty to have a reposize,
+		-- whose maxsize has been set.
+		let reposizes' = foldl'
+			(\m u -> M.insertWith (flip const) u (RepoSize 0) m)
+			reposizes
+			(M.keys maxsizes)
+		let reposizes'' = flip M.withoutKeys deadset reposizes'
 		let l = reverse $ sortOn snd $ M.toList $
-			M.mapWithKey (gather maxsizes) reposizes
+			M.mapWithKey (gather maxsizes) reposizes''
 		v <- Remote.prettyPrintUUIDsWith' False (Just "size")
 		 	"repositories" descmap showsizes l
 		showRaw $ encodeBS $ tablerow (zip widths headers)
@@ -89,11 +96,10 @@ sizeOverview o = do
 	sizefield = "size" :: T.Text
 	maxsizefield = "maxsize" :: T.Text
 	
-	gather maxsizes u (RepoSize currsize) = Just $
-			M.fromList
-				[ (sizefield, Just currsize)
-				, (maxsizefield, fromMaxSize <$> M.lookup u maxsizes)
-				]
+	gather maxsizes u (RepoSize currsize) = Just $ M.fromList
+		[ (sizefield, Just currsize)
+		, (maxsizefield, fromMaxSize <$> M.lookup u maxsizes)
+		]
 
 	(widths, headers) = unzip
 		[ (7, "size")

doc/todo/git-annex_proxies.mdwn

@@ -35,21 +35,6 @@ Planned schedule of work:
 * `git-annex assist --rebalance` of `balanced=foo:2` 
   sometimes needs several runs to stabalize.
 
-* Bug:
-
-    git init foo
-    cd foo
-    git-annex init
-    git commit --allow-empty -m foo
-    cd ..
-    git clone foo bar
-    cd foo
-    git remote add bar ../bar
-    git-annex maxsize bar
-
-    Now `git-annex maxsize` will omit displaying bar. This is because the
-    DB got written without it.
-
 * Concurrency issues with RepoSizes calculation and balanced content:
 
   * What if 2 concurrent threads are considering sending two different