When a key's size is unknown, still check the annex.diskreserve, and avoid getting content if the disk is too full.

We can't check if there's enough disk space to download the content,
but we *can* check if there's certainly not enough!

Annex/Content.hs

@@ -280,17 +280,19 @@ withTmp key action = do
 {- Checks that there is disk space available to store a given key,
  - in a destination (or the annex) printing a warning if not. -}
 checkDiskSpace :: Maybe FilePath -> Key -> Integer -> Annex Bool
-checkDiskSpace destination key alreadythere = do
-	reserve <- annexDiskReserve <$> Annex.getGitConfig
-	free <- liftIO . getDiskFree =<< dir
-	force <- Annex.getState Annex.force
-	case (free, keySize key) of
-		(Just have, Just need) -> do
-			let ok = (need + reserve <= have + alreadythere) || force
-			unless ok $
-				needmorespace (need + reserve - have - alreadythere)
-			return ok
-		_ -> return True
+checkDiskSpace destination key alreadythere = ifM (Annex.getState Annex.force)
+	( return True
+	, do
+		reserve <- annexDiskReserve <$> Annex.getGitConfig
+		free <- liftIO . getDiskFree =<< dir
+		case (free, fromMaybe 1 (keySize key)) of
+			(Just have, need) -> do
+				let ok = (need + reserve <= have + alreadythere)
+				unless ok $
+					needmorespace (need + reserve - have - alreadythere)
+				return ok
+			_ -> return True
+	)
   where
 	dir = maybe (fromRepo gitAnnexDir) return destination
 	needmorespace n =

debian/changelog

@@ -12,6 +12,8 @@ git-annex (5.20150410) UNRELEASED; urgency=medium
   * bittorrent: Fix handling of magnet links.
   * Windows: Fixed support of remotes on other drives.
     (A reversion introduced in version 5.20150113.)
+  * When a key's size is unknown, still check the annex.diskreserve,
+    and avoid getting content if the disk is too full.
 
  -- Joey Hess <id@joeyh.name>  Thu, 09 Apr 2015 20:59:43 -0400