bug #1096: whd_stack on one arg of conversion had side-effect on the other arg

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@8782 85f007b7-540e-0410-9357-904b9bb8a0f7

2 files changed, 16 insertions, 9 deletions

diff --git a/kernel/closure.ml b/kernel/closure.ml
index 625d3b0d0..abbc66077 100644
--- a/kernel/closure.ml
+++ b/kernel/closure.ml
@@ -554,7 +554,7 @@ let rec lft_fconstr n ft =
     | FFix(fx,e) -> {norm=Cstr; term=FFix(fx,subs_shft(n,e))}
     | FCoFix(cfx,e) -> {norm=Cstr; term=FCoFix(cfx,subs_shft(n,e))}
     | FLIFT(k,m) -> lft_fconstr (n+k) m
-    | FLOCKED -> anomaly "lft_constr found locked term"
+    | FLOCKED -> assert false
     | _ -> {norm=ft.norm; term=FLIFT(n,ft)}
 let lift_fconstr k f =
   if k=0 then f else lft_fconstr k f
@@ -772,8 +772,7 @@ let rec to_constr constr_fun lfts v =
         let fr = mk_clos2 env t in
         let unfv = update v (fr.norm,fr.term) in
         to_constr constr_fun lfts unfv
-    | FLOCKED -> (*anomaly "Closure.to_constr: found locked term"*)
-mkVar(id_of_string"_LOCK_")
+    | FLOCKED -> assert false (*mkVar(id_of_string"_LOCK_")*)
 
 (* This function defines the correspondance between constr and
    fconstr. When we find a closure whose substitution is the identity,
@@ -949,7 +948,7 @@ let contract_fix_vect fix =
           (bds.(i),
 	   (fun j -> { norm = Cstr; term = FCoFix ((j,rdcl),env) }),
 	   env, Array.length bds)
-      | _ -> anomaly "Closure.contract_fix_vect: not a (co)fixpoint" 
+      | _ -> assert false
   in
   let rec subst_bodies_from_i i env =
     if i = nfix then
@@ -969,7 +968,7 @@ let rec knh m stk =
   match m.term with
     | FLIFT(k,a) -> knh a (zshift k stk)
     | FCLOS(t,e) -> knht e t (zupdate m stk)
-    | FLOCKED -> anomaly "Closure.knh: found lock"
+    | FLOCKED -> assert false
     | FApp(a,b) -> knh a (append_stack b (zupdate m stk))
     | FCases(ci,p,t,br) -> knh t (Zcase(ci,p,br)::zupdate m stk)
     | FFix(((ri,n),(_,_,_)),_) ->
diff --git a/kernel/reduction.ml b/kernel/reduction.ml
index 2467e941f..4aa7c5753 100644
--- a/kernel/reduction.ml
+++ b/kernel/reduction.ml
@@ -291,10 +291,18 @@ and eqappr cv_pb infos appr1 appr2 cuniv =
            convert_stacks infos lft1 lft2 v1 v2 u2
          else raise NotConvertible
 
-    | ( (FLetIn _, _) | (_, FLetIn _) | (FCases _,_) | (_,FCases _)
-      | (FApp _,_) | (_,FApp _) | (FCLOS _, _) | (_,FCLOS _)
-      | (FLIFT _, _) | (_,FLIFT _) | (FLOCKED,_) | (_,FLOCKED)) ->
-        anomaly "Unexpected term returned by fhnf"
+    (* Can happen because whd_stack on one arg may have side-effects
+       on the other arg and coulb be no more in hnf... *)
+    | ( (FLetIn _, _) | (FCases _,_) | (FApp _,_)
+      | (FCLOS _, _) | (FLIFT _, _)) ->
+        eqappr cv_pb infos (lft1, whd_stack infos hd1 v1) appr2 cuniv
+
+    | ( (_, FLetIn _) | (_,FCases _) | (_,FApp _)
+      | (_,FCLOS _) | (_,FLIFT _)) ->
+        eqappr cv_pb infos (lft1, whd_stack infos hd1 v1) appr2 cuniv
+
+    (* Should not happen because whd_stack unlocks references *)
+    | ((FLOCKED,_) | (_,FLOCKED)) -> assert false
 
      | _ -> raise NotConvertible