Index: ghc6-6.12.1/utils/haddock/src/Haddock/Backends/Html.hs
===================================================================
--- ghc6-6.12.1.orig/utils/haddock/src/Haddock/Backends/Html.hs	2010-02-09 12:27:23.000000000 +0200
+++ ghc6-6.12.1/utils/haddock/src/Haddock/Backends/Html.hs	2010-02-09 12:29:30.000000000 +0200
@@ -1855,7 +1855,7 @@
           case maybe_wiki_url of
             Nothing  -> Html.emptyTable
             Just url -> tda [theclass "declbut"] <<
-                          let url' = spliceURL (Just fname) (Just mdl)
+                          let url' = spliceURL (Just fname) mdl
                                                (Just n) (Just loc) url
                            in anchor ! [href url'] << toHtml "Comments"
   
@@ -1865,8 +1865,9 @@
         -- the module defining the type family, which is wrong.
         origMod = nameModule n
 
-        -- Name must be documented, otherwise we wouldn't get here
-        Documented n mdl = name
+        (n,mdl) = case name of
+                    Documented n' mdl' -> (n', Just mdl')
+                    Undocumented n' -> (n', Nothing)
 
         fname = unpackFS (srcSpanFile loc)
 
