importfeed: Better error message when downloading the feed fails

It used to display the "bad feed content" message indicating there were no
enclosures found, which was misleading when the http request for the feed
failed.

This commit was sponsored by Ewen McNeill on Patreon.

CHANGELOG

@@ -11,6 +11,7 @@ git-annex (7.20181212) UNRELEASED; urgency=medium
   * unused: Update suggested git log message to see where data was previously
     used so it will also work with v7 unlocked pointer files.
   * Fix doubled progress display when downloading an url when -J is used.
+  * importfeed: Better error message when downloading the feed fails.
 
  -- Joey Hess <id@joeyh.name>  Tue, 18 Dec 2018 12:24:52 -0400
 

Command/ImportFeed.hs

@@ -75,9 +75,10 @@ start opts cache url = do
 	next $ perform opts cache url
 
 perform :: ImportFeedOptions -> Cache -> URLString -> CommandPerform
-perform opts cache url = do
+perform opts cache url = go =<< downloadFeed url
-	v <- findDownloads url
+  where
-	case v of
+	go Nothing = next $ feedProblem url "downloading the feed failed"
+	go (Just f) = case findDownloads url f of
 		[] -> next $
 			feedProblem url "bad feed content; no enclosures to download"
 		l -> do
@@ -128,13 +129,10 @@ knownItems (k, u) = do
 		<$> getCurrentMetaData k
 	return (itemids, u)
 
-findDownloads :: URLString -> Annex [ToDownload]
+findDownloads :: URLString -> Feed -> [ToDownload]
-findDownloads u = go <$> downloadFeed u
+findDownloads u f = catMaybes $ map mk (feedItems f)
   where
-	go Nothing = []
+	mk i = case getItemEnclosure i of
-	go (Just f) = catMaybes $ map (mk f) (feedItems f)
-
-	mk f i = case getItemEnclosure i of
 		Just (enclosureurl, _, _) ->
 			Just $ ToDownload f u i $ Enclosure $ 
 				fromFeed enclosureurl