Adjust behaviour of gcd

[ghc-base.git] / GHC / IO / Handle.hs

diff --git a/GHC/IO/Handle.hs b/GHC/IO/Handle.hs
index bb45b15..fcfa92d 100644 (file)
--- a/GHC/IO/Handle.hs
+++ b/GHC/IO/Handle.hs
@@ -1,5 +1,9 @@
+{-# LANGUAGE CPP
+           , NoImplicitPrelude
+           , RecordWildCards
+           , NondecreasingIndentation
+  #-}
 {-# OPTIONS_GHC -fno-warn-unused-matches #-}
-{-# LANGUAGE NoImplicitPrelude, RecordWildCards #-}
 
 -----------------------------------------------------------------------------
 -- |
@@ -82,14 +86,11 @@ hClose h@(FileHandle _ m)     = do
   mb_exc <- hClose' h m
   hClose_maybethrow mb_exc h
 hClose h@(DuplexHandle _ r w) = do
-  mb_exc1 <- hClose' h w
-  mb_exc2 <- hClose' h r
-  case mb_exc1 of
-    Nothing -> return ()
-    Just e  -> hClose_maybethrow mb_exc2 h
+  excs <- mapM (hClose' h) [r,w]
+  hClose_maybethrow (listToMaybe (catMaybes excs)) h
 
 hClose_maybethrow :: Maybe SomeException -> Handle -> IO ()
-hClose_maybethrow Nothing  h  = return ()
+hClose_maybethrow Nothing  h = return ()
 hClose_maybethrow (Just e) h = hClose_rethrow e h
 
 hClose_rethrow :: SomeException -> Handle -> IO ()
@@ -417,14 +418,17 @@ hTell handle =
 
       posn <- IODevice.tell haDevice
 
-      cbuf <- readIORef haCharBuffer
+      -- we can't tell the real byte offset if there are buffered
+      -- Chars, so must flush first:
+      flushCharBuffer handle_
+
       bbuf <- readIORef haByteBuffer
 
-      let real_posn 
-           | isWriteBuffer cbuf = posn + fromIntegral (bufR cbuf)
-           | otherwise = posn - fromIntegral (bufR cbuf - bufL cbuf)
-                              - fromIntegral (bufR bbuf - bufL bbuf)
+      let real_posn
+           | isWriteBuffer bbuf = posn + fromIntegral (bufferElems bbuf)
+           | otherwise          = posn - fromIntegral (bufferElems bbuf)
 
+      cbuf <- readIORef haCharBuffer
       debugIO ("\nhGetPosn: (posn, real_posn) = " ++ show (posn, real_posn))
       debugIO ("   cbuf: " ++ summaryBuffer cbuf ++
             "   bbuf: " ++ summaryBuffer bbuf)
@@ -547,7 +551,7 @@ hIsTerminalDevice handle = do
 -- | Select binary mode ('True') or text mode ('False') on a open handle.
 -- (See also 'openBinaryFile'.)
 --
--- This has the same effect as calling 'hSetEncoding' with 'latin1', together
+-- This has the same effect as calling 'hSetEncoding' with 'char8', together
 -- with 'hSetNewlineMode' with 'noNewlineTranslation'.
 --
 hSetBinaryMode :: Handle -> Bool -> IO ()