fix strictness issue

Recent changes to Utility.Gpg exposed a strictness bug in how Creds
uses it.

Creds.hs

@@ -35,6 +35,7 @@ import Remote.Helper.Encryptable (remoteCipher, remoteCipher', embedCreds, Encry
 import Utility.Env (getEnv)
 
 import qualified Data.ByteString.Lazy.Char8 as L
+import qualified Data.ByteString.Char8 as S
 import qualified Data.Map as M
 import Utility.Base64
 
@@ -86,7 +87,7 @@ setRemoteCredPair' mkval parseconfig encsetup c gc storage mcreds = case mcreds
 		cmd <- gpgCmd <$> Annex.getGitConfig
 		s <- liftIO $ encrypt cmd (pc, gc) cipher
 			(feedBytes $ L.pack $ encodeCredPair creds)
-			(readBytes $ return . L.unpack)
+			(readBytesStrictly $ return . S.unpack)
 		return $ M.insert key (mkval (Accepted (toB64 s))) c
 	storeconfig creds key Nothing =
 		return $ M.insert key (mkval (Accepted (toB64 $ encodeCredPair creds))) c
@@ -114,7 +115,7 @@ getRemoteCredPair c gc storage = maybe fromcache (return . Just) =<< fromenv
 		cmd <- gpgCmd <$> Annex.getGitConfig
 		mcreds <- liftIO $ catchMaybeIO $ decrypt cmd (c, gc) cipher
 			(feedBytes $ L.pack $ fromB64 enccreds)
-			(readBytes $ return . L.unpack)
+			(readBytesStrictly $ return . S.unpack)
 		case mcreds of
 			Just creds -> fromcreds creds
 			Nothing -> do

Crypto.hs

@@ -28,6 +28,7 @@ module Crypto (
 	feedFile,
 	feedBytes,
 	readBytes,
+	readBytesStrictly,
 	encrypt,
 	decrypt,
 	LensGpgEncParams(..),
@@ -187,25 +188,35 @@ feedBytes = flip L.hPut
 readBytes :: (MonadIO m) => (L.ByteString -> m a) -> Reader m a
 readBytes a h = liftIO (L.hGetContents h) >>= a
 
+readBytesStrictly :: (MonadIO m) => (S.ByteString -> m a) -> Reader m a
+readBytesStrictly a h = liftIO (S.hGetContents h) >>= a
+
+
 {- Runs a Feeder action, that generates content that is symmetrically
  - encrypted with the Cipher (unless it is empty, in which case
  - public-key encryption is used) using the given gpg options, and then
- - read by the Reader action. -}
+ - read by the Reader action. 
+ -
+ - Note that the Reader must fully consume gpg's input before returning.
+ -}
 encrypt :: (MonadIO m, MonadMask m, LensGpgEncParams c) => Gpg.GpgCmd -> c -> Cipher -> Feeder -> Reader m a -> m a
 encrypt cmd c cipher = case cipher of
 	Cipher{} -> Gpg.feedRead cmd (params ++ Gpg.stdEncryptionParams True) $
 			cipherPassphrase cipher
-	MacOnlyCipher{} -> Gpg.pipeLazy cmd $ params ++ Gpg.stdEncryptionParams False
+	MacOnlyCipher{} -> Gpg.feedRead' cmd $ params ++ Gpg.stdEncryptionParams False
   where
 	params = getGpgEncParams c
 
 {- Runs a Feeder action, that generates content that is decrypted with the
  - Cipher (or using a private key if the Cipher is empty), and read by the
- - Reader action. -}
+ - Reader action.
+ -
+ - Note that the Reader must fully consume gpg's input before returning.
+ - -}
 decrypt :: (MonadIO m, MonadMask m, LensGpgEncParams c) => Gpg.GpgCmd -> c -> Cipher -> Feeder -> Reader m a -> m a
 decrypt cmd c cipher = case cipher of
 	Cipher{} -> Gpg.feedRead cmd params $ cipherPassphrase cipher
-	MacOnlyCipher{} -> Gpg.pipeLazy cmd params
+	MacOnlyCipher{} -> Gpg.feedRead' cmd params
   where
 	params = Param "--decrypt" : getGpgDecParams c
 

Utility/Gpg.hs

@@ -17,7 +17,7 @@ module Utility.Gpg (
 	stdEncryptionParams,
 	pipeStrict,
 	feedRead,
-	pipeLazy,
+	feedRead',
 	findPubKeys,
 	UserId,
 	secretKeys,
@@ -149,8 +149,7 @@ pipeStrict (GpgCmd cmd) params input = do
  - Runs gpg in batch mode; this is necessary to avoid gpg 2.x prompting for
  - the passphrase.
  -
- - Note that to avoid deadlock with the cleanup stage,
+ - Note that the reader must fully consume gpg's input before returning. -}
- - the reader must fully consume gpg's input before returning. -}
 feedRead :: (MonadIO m, MonadMask m) => GpgCmd -> [CommandParam] -> String -> (Handle -> IO ()) -> (Handle -> m a) -> m a
 feedRead cmd params passphrase feeder reader = do
 #ifndef mingw32_HOST_OS
@@ -179,11 +178,11 @@ feedRead cmd params passphrase feeder reader = do
 		go $ passphrasefile ++ params
 #endif
   where
-	go params' = pipeLazy cmd params' feeder reader
+	go params' = feedRead' cmd params' feeder reader
 
 {- Like feedRead, but without passphrase. -}
-pipeLazy :: (MonadIO m, MonadMask m) => GpgCmd -> [CommandParam] -> (Handle -> IO ()) -> (Handle -> m a) -> m a
+feedRead' :: (MonadIO m, MonadMask m) => GpgCmd -> [CommandParam] -> (Handle -> IO ()) -> (Handle -> m a) -> m a
-pipeLazy (GpgCmd cmd) params feeder reader = do
+feedRead' (GpgCmd cmd) params feeder reader = do
 	params' <- liftIO $ stdParams $ Param "--batch" : params
 	let p = (proc cmd params')
 		{ std_in = CreatePipe