[project @ 1998-08-11 21:40:32 by sof]

[ghc-hetmet.git] / ghc / lib / misc / PackedString.lhs

diff --git a/ghc/lib/misc/PackedString.lhs b/ghc/lib/misc/PackedString.lhs
index 752891a..2334b2f 100644 (file)
--- a/ghc/lib/misc/PackedString.lhs
+++ b/ghc/lib/misc/PackedString.lhs
@@ -1098,7 +1098,9 @@ unpackCString# addr
        ch = indexCharOffAddr# addr nh
 
 unpackCStringIO :: Addr -> IO String
-unpackCStringIO addr = unpack 0#
+unpackCStringIO addr
+ | addr == ``NULL'' = return ""
+ | otherwise        = unpack 0#
   where
     unpack nh = do
        ch <- readCharOffAddr addr (I# nh)