Corrected nonblocking messages

src/HWiid.hsc

@@ -27,6 +27,8 @@ module HWiid ( BDAddr(..)
              , hwiidButtonPlus
              , hwiidNunchukButtonZ
              , hwiidNunchukButtonC
+             , hwiidMesgTypeStatus
+             , hwiidMesgTypeButton
              , hwiidOpen
              , hwiidOpenTimeout
              , hwiidClose
@@ -48,7 +50,6 @@ import Foreign.Ptr
 import Foreign.Storable
 import System.Posix.Clock (TimeSpec)
 
-
 #include <cwiid.h>
 
 hwiidFlagMesgInterface :: CInt
@@ -244,11 +245,12 @@ foreign import ccall unsafe "cwiid.h cwiid_get_mesg"
 
 hwiidGetMesg :: Wiimote -> IO [WiimoteMesg]
 hwiidGetMesg wiimote = alloca $ \countptr -> alloca $ \arrayptr -> alloca $ \timestamp -> do
-                         cwiid_get_mesg wiimote countptr arrayptr timestamp
+                         ret <- cwiid_get_mesg wiimote countptr arrayptr timestamp
                          count <- peek countptr
                          array <- peek arrayptr
                          
-                         ret <- peekArray (fromIntegral count) array
-                         free array
-                         
-                         return ret
+                         if (ret == 0) then do
+                           list <- peekArray (fromIntegral count) array
+                           free array
+                           return list
+                                       else return []