Fix #2062: foldr1 problem in hpc tool

[ghc-hetmet.git] / utils / hpc / HpcOverlay.hs

diff --git a/utils/hpc/HpcOverlay.hs b/utils/hpc/HpcOverlay.hs
index 0cf56e4..76cc76e 100644 (file)
--- a/utils/hpc/HpcOverlay.hs
+++ b/utils/hpc/HpcOverlay.hs
@@ -138,9 +138,10 @@ qualifier pos (Just (AtPosition l1' c1' l2' c2'))
          = (l1', c1', l2', c2') == fromHpcPos pos
 
 concatSpec :: [Spec] -> Spec
-concatSpec = foldl1 $ 
-              \ (Spec pre1 body1) (Spec pre2 body2) 
-                    -> Spec (pre1 ++ pre2) (body1 ++ body2)
+concatSpec = foldr 
+              (\ (Spec pre1 body1) (Spec pre2 body2) 
+                    -> Spec (pre1 ++ pre2) (body1 ++ body2))
+               (Spec [] [])