use parseFeedFromFile to avoid mojibake

As mentioned in commit 2bd778a46ed071c2dd534ebe3b7007b7ae60d1c1, there
was mojibake when LANG=C.

Looking at parseFeedFromFile, it is very particular to read the file as
unicode. parseFeedString looks like it will accept any old String,
but a String that was read using the filesystem encoding will not in
fact have the right encoding.

I think this is a bug in the feed library and will file one.

Sponsored-by: Svenne Krap on Patreon

diff --git a/Command/ImportFeed.hs b/Command/ImportFeed.hs
index 922e354c212d6968765f03798097920359a59102..6eda9afba454669ce408dc9d01f37d3529001f48 100644 (file)
--- a/Command/ImportFeed.hs
+++ b/Command/ImportFeed.hs
@@ -78,22 +78,29 @@ seek o = do
 getFeed :: AddUnlockedMatcher -> ImportFeedOptions -> Cache -> URLString -> CommandSeek
 getFeed addunlockedmatcher opts cache url = do
        showStartOther "importfeed" (Just url) (SeekInput [])
-       downloadFeed url >>= \case
-               Nothing -> showEndResult =<< feedProblem url
-                       "downloading the feed failed"
-               Just feedcontent -> case parseFeedString feedcontent of
-                       Nothing -> debugfeedcontent feedcontent "parsing the feed failed"
-                       Just f -> case findDownloads url f of
-                               [] -> debugfeedcontent feedcontent "bad feed content; no enclosures to download"
-                               l -> do
-                                       showEndOk
-                                       ifM (and <$> mapM (performDownload addunlockedmatcher opts cache) l)
-                                               ( clearFeedProblem url
-                                               , void $ feedProblem url 
-                                                       "problem downloading some item(s) from feed"
-                                               )
+       withTmpFile "feed" $ \tmpf h -> do
+               liftIO $ hClose h
+               ifM (downloadFeed url tmpf)
+                       ( go tmpf
+                       , showEndResult =<< feedProblem url
+                               "downloading the feed failed"
+                       )
   where
-       debugfeedcontent feedcontent msg = do
+       -- Use parseFeedFromFile rather than reading the file
+       -- ourselves because it goes out of its way to handle encodings.
+       go tmpf = liftIO (parseFeedFromFile tmpf) >>= \case
+               Nothing -> debugfeedcontent tmpf "parsing the feed failed"
+               Just f -> case findDownloads url f of
+                       [] -> debugfeedcontent tmpf "bad feed content; no enclosures to download"
+                       l -> do
+                               showEndOk
+                               ifM (and <$> mapM (performDownload addunlockedmatcher opts cache) l)
+                                       ( clearFeedProblem url
+                                       , void $ feedProblem url 
+                                               "problem downloading some item(s) from feed"
+                                       )
+       debugfeedcontent tmpf msg = do
+               feedcontent <- liftIO $ readFile tmpf
                fastDebug "Command.ImportFeed" $ unlines
                        [ "start of feed content"
                        , feedcontent
@@ -170,15 +177,11 @@ findDownloads u f = catMaybes $ map mk (feedItems f)
                        Nothing -> Nothing
 
 {- Feeds change, so a feed download cannot be resumed. -}
-downloadFeed :: URLString -> Annex (Maybe String)
-downloadFeed url
+downloadFeed :: URLString -> FilePath -> Annex Bool
+downloadFeed url f
        | Url.parseURIRelaxed url == Nothing = giveup "invalid feed url"
-       | otherwise = withTmpFile "feed" $ \f h -> do
-               liftIO $ hClose h
-               ifM (Url.withUrlOptions $ Url.download nullMeterUpdate Nothing url f)
-                       ( Just <$> liftIO (readFileStrict f)
-                       , return Nothing
-                       )
+       | otherwise = Url.withUrlOptions $
+               Url.download nullMeterUpdate Nothing url f
 
 performDownload :: AddUnlockedMatcher -> ImportFeedOptions -> Cache -> ToDownload -> Annex Bool
 performDownload addunlockedmatcher opts cache todownload = case location todownload of