hGetContents: close the handle properly on error

When hGetContents caught an error it was closing the handle and then
throwing the exception, without updating the handle with the new
closed state.  This lead to a double-closed, which was the cause of

*** glibc detected *** ./Setup: double free or corruption

when iconv_close was called twice on the decoder.

See http://hackage.haskell.org/trac/hackage/ticket/609

diff --git a/GHC/IO/Handle/Text.hs b/GHC/IO/Handle/Text.hs
index ebbacd4..c490643 100644 (file)
--- a/GHC/IO/Handle/Text.hs
+++ b/GHC/IO/Handle/Text.hs
@@ -31,6 +31,7 @@ import GHC.IO.FD
 import GHC.IO.Buffer
 import qualified GHC.IO.BufferedIO as Buffered
 import GHC.IO.Exception
+import GHC.Exception
 import GHC.IO.Handle.Types
 import GHC.IO.Handle.Internals
 import qualified GHC.IO.Device as IODevice
@@ -381,11 +382,14 @@ lazyReadBuffered h handle_@Handle__{..} = do
                   debugIO ("hGetContents caught: " ++ show e)
                   -- We might have a \r cached in CRLF mode.  So we
                   -- need to check for that and return it:
-                  if isEOFError e
-                     then if not (isEmptyBuffer buf)
-                             then return (handle_', "\r")
-                             else return (handle_', "")
-                     else ioError e
+                  let r = if isEOFError e
+                             then if not (isEmptyBuffer buf)
+                                     then "\r"
+                                     else ""
+                             else
+                                  throw (augmentIOError e "hGetContents" h)
+
+                  return (handle_', r)
         )
 
 -- ensure we have some characters in the buffer