[commit: ghc] ghc-7.8: Fix #8917. (3dbbe12)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : ghc-7.8
Link       : http://ghc.haskell.org/trac/ghc/changeset/3dbbe12dba3ae95d7215164dbdc751c051a0be08/ghc

>---------------------------------------------------------------

commit 3dbbe12dba3ae95d7215164dbdc751c051a0be08
Author: Richard Eisenberg <eir at cis.upenn.edu>
Date:   Sat Mar 22 13:13:26 2014 -0400

    Fix #8917.
    
    FamInstEnv.normaliseTcApp should normalise arguments even when
    the top-level tycon isn't a type family. This was a regression
    from 7.6 -- not sure when it happened, but it was probably my
    fault. Fixed now, in any case.
    
    (cherry picked from commit c99941cfeee033fca2df45e9523b65c83be20d31)


>---------------------------------------------------------------

3dbbe12dba3ae95d7215164dbdc751c051a0be08
 compiler/types/FamInstEnv.lhs |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/compiler/types/FamInstEnv.lhs b/compiler/types/FamInstEnv.lhs
index c17668b..bf89484 100644
--- a/compiler/types/FamInstEnv.lhs
+++ b/compiler/types/FamInstEnv.lhs
@@ -957,9 +957,9 @@ normaliseTcApp env role tc tys
 
   | otherwise   -- No unique matching family instance exists;
                 -- we do not do anything
-  = (Refl role ty, ty)
-  where
-    ty = mkTyConApp tc tys
+  = let (co, ntys) = normaliseTcArgs env role tc tys in
+    (co, mkTyConApp tc ntys)
+    
 
 ---------------
 normaliseTcArgs :: FamInstEnvs            -- environment with family instances