X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=GHC%2FIO.hs;h=b3d590a02d455ee733c4f861f154a7da50a30590;hb=c81f31abd5c00d14a95a94a7b66d9853fc6c03ac;hp=32018e9e62f9f1c168be8510c3efc617c95fe610;hpb=b706340c451952adf230b5b8daecad8a1f34d714;p=ghc-base.git

diff --git a/GHC/IO.hs b/GHC/IO.hs
index 32018e9..b3d590a 100644
--- a/GHC/IO.hs
+++ b/GHC/IO.hs
@@ -168,10 +168,13 @@ hGetLineBufferedLoop handle_ ref
 #endif
 
   xs <- unpack raw r off
+
+  -- if eol == True, then off is the offset of the '\n'
+  -- otherwise off == w and the buffer is now empty.
   if eol
-	then do if w == off + 1
-		   then writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
-		   else writeIORef ref buf{ bufRPtr = off + 1 }
+	then do if (w == off + 1)
+	    		then writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
+		   	else writeIORef ref buf{ bufRPtr = off + 1 }
 	        return (concat (reverse (xs:xss)))
 	else do
 	     maybe_buf <- maybeFillReadBuffer (haFD handle_) True (haIsStream handle_)
@@ -179,10 +182,12 @@ hGetLineBufferedLoop handle_ ref
 	     case maybe_buf of
 		-- Nothing indicates we caught an EOF, and we may have a
 		-- partial line to return.
-		Nothing -> let str = concat (reverse (xs:xss)) in
-		     	   if not (null str)
-			      then return str
-			      else ioe_EOF
+		Nothing -> do
+		     writeIORef ref buf{ bufRPtr=0, bufWPtr=0 }
+		     let str = concat (reverse (xs:xss))
+		     if not (null str)
+		        then return str
+		        else ioe_EOF
 		Just new_buf -> 
 		     hGetLineBufferedLoop handle_ ref new_buf (xs:xss)
 
@@ -607,7 +612,8 @@ hPutBuf :: Handle			-- handle to write to
 	-> Int				-- number of bytes of data in buffer
 	-> IO ()
 hPutBuf handle ptr count
-  | count <= 0 = illegalBufferSize handle "hPutBuf" count
+  | count == 0 = return ()
+  | count <  0 = illegalBufferSize handle "hPutBuf" count
   | otherwise = 
     wantWritableHandle "hPutBuf" handle $ 
       \ handle_@Handle__{ haFD=fd, haBuffer=ref, haIsStream=is_stream } -> do
@@ -647,7 +653,8 @@ writeChunk fd ptr bytes = loop 0 bytes
 
 hGetBuf :: Handle -> Ptr a -> Int -> IO Int
 hGetBuf handle ptr count
-  | count <= 0 = illegalBufferSize handle "hGetBuf" count
+  | count == 0 = return 0
+  | count <  0 = illegalBufferSize handle "hGetBuf" count
   | otherwise = 
       wantReadableHandle "hGetBuf" handle $ 
 	\ handle_@Handle__{ haFD=fd, haBuffer=ref } -> do
@@ -694,6 +701,7 @@ slurpFile fname = do
     ioError (userError "slurpFile: file too big")
    else do
     let sz_i = fromIntegral sz
+    if sz_i == 0 then return (nullPtr, 0) else do
     chunk <- mallocBytes sz_i
     r <- hGetBuf handle chunk sz_i
     hClose handle