make --json-progress work for url downloads

Annex/Content.hs

@@ -902,7 +902,7 @@ saveState nocommit = doSideAction $ do
 
 {- Downloads content from any of a list of urls. -}
 downloadUrl :: Key -> MeterUpdate -> [Url.URLString] -> FilePath -> Annex Bool
-downloadUrl k p urls file = concurrentMeteredFile file (Just p) k $
+downloadUrl k p urls file = meteredFile file (Just p) k $
 	go =<< annexWebDownloadCommand <$> Annex.getGitConfig
   where
 	go Nothing = do

Messages/Progress.hs

@@ -75,25 +75,29 @@ metered othermeter key a = case keySize key of
 		Just om -> combineMeterUpdate m om
 
 {- Use when the command's own progress output is preferred.
- - The command's output will be suppressed and git-annex's progress output
+ - The command's output will be suppressed and git-annex's progress meter
  - used for concurrent output, and json progress. -}
 commandMetered :: Maybe MeterUpdate -> Key -> (MeterUpdate -> Annex a) -> Annex a
 commandMetered combinemeterupdate key a = 
-	withMessageState $ \s -> case outputType s of
-		JSONOutput True -> usemeter
-		NormalOutput | concurrentOutputEnabled s -> usemeter
-		_ -> a (fromMaybe nullMeterUpdate combinemeterupdate)
-  where
-	usemeter = metered combinemeterupdate key a
+	withMessageState $ \s -> if needOutputMeter s
+		then metered combinemeterupdate key a
+		else a (fromMaybe nullMeterUpdate combinemeterupdate)
 
-{- Poll file size to display meter, but only for concurrent output. -}
-concurrentMeteredFile :: FilePath -> Maybe MeterUpdate -> Key -> Annex a -> Annex a
-concurrentMeteredFile file combinemeterupdate key a = 
-	withMessageState $ \s -> if concurrentOutputEnabled s
+{- Poll file size to display meter, but only when concurrent output or
+ - json progress needs the information. -}
+meteredFile :: FilePath -> Maybe MeterUpdate -> Key -> Annex a -> Annex a
+meteredFile file combinemeterupdate key a = 
+	withMessageState $ \s -> if needOutputMeter s
 		then metered combinemeterupdate key $ \p ->
 			watchFileSize file p a
 		else a
 
+needOutputMeter :: MessageState -> Bool
+needOutputMeter s = case outputType s of
+	JSONOutput True -> True
+	NormalOutput | concurrentOutputEnabled s -> True
+	_ -> False
+
 {- Progress dots. -}
 showProgressDots :: Annex ()
 showProgressDots = outputMessage JSON.none "."