Fix PR#6365

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14565 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

testsuite/tests/typing-modules/aliases.ml

@@ -192,3 +192,9 @@ module M = struct
   end
 end;;
 module type S = module type of M ;;
+
+(* PR#6365 *)
+module type S = sig module M : sig type t val x : t end end;;
+module H = struct type t = A let x = A end;;
+module H' = H;;
+module type S' = S with module M = H';; (* shouldn't introduce an alias *)

testsuite/tests/typing-modules/aliases.ml.reference

@@ -347,4 +347,8 @@ Error: In this `with' constraint, the new definition of I
     module Q :
       sig type wrap' = wrap = W of (Set.Make(Int).t, Set.Make(N.I).t) eq end
   end
+#     module type S = sig module M : sig type t val x : t end end
+# module H : sig type t = A val x : t end
+# module H' = H
+# module type S' = sig module M : sig type t = H.t = A val x : t end end
 # 

typing/typemod.ml

@@ -198,7 +198,8 @@ let merge_constraint initial_env loc sg constr =
       when Ident.name id = s ->
         let path = Typetexp.find_module initial_env loc lid.txt in
         let md' = Env.find_module path env in
-        let newmd = Mtype.strengthen_decl env md' path in
+        let md'' = {md' with md_type = Mtype.remove_aliases env md'.md_type} in
+        let newmd = Mtype.strengthen_decl env md'' path in
         ignore(Includemod.modtypes env newmd.md_type md.md_type);
         (Pident id, lid, Twith_module (path, lid)),
         Sig_module(id, newmd, rs) :: rem