X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcRnMonad.lhs;h=ce84178e10a9effbe677ab84dc46ce47d1511093;hp=545258c9f16bb377e8c13f9d8946c43048cb326e;hb=0b4324456e472d15a3a124f56387486f71cb765d;hpb=a1fae73a83665d7b9134509e80d34ff69a009cc7

diff --git a/compiler/typecheck/TcRnMonad.lhs b/compiler/typecheck/TcRnMonad.lhs
index 545258c..ce84178 100644
--- a/compiler/typecheck/TcRnMonad.lhs
+++ b/compiler/typecheck/TcRnMonad.lhs
@@ -494,9 +494,10 @@ getSrcSpanM :: TcRn SrcSpan
 getSrcSpanM = do { env <- getLclEnv; return (tcl_loc env) }
 
 setSrcSpan :: SrcSpan -> TcRn a -> TcRn a
-setSrcSpan loc thing_inside
-  | isGoodSrcSpan loc = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
-  | otherwise	      = thing_inside	-- Don't overwrite useful info with useless
+setSrcSpan loc@(RealSrcSpan _) thing_inside
+    = updLclEnv (\env -> env { tcl_loc = loc }) thing_inside
+-- Don't overwrite useful info with useless:
+setSrcSpan (UnhelpfulSpan _) thing_inside = thing_inside
 
 addLocM :: (a -> TcM b) -> Located a -> TcM b
 addLocM fn (L loc a) = setSrcSpan loc $ fn a