Fixing logical bugs in the presence of let-ins in computiong primitive

projections.

- lift accounting for the record missing in computing the subst from
  fields to projections of the record
- substitution for parameters should not lift the local definitions
- typo in building the latter (subst -> letsubst)

2 files changed, 23 insertions, 9 deletions

diff --git a/kernel/indtypes.ml b/kernel/indtypes.ml
index 351de9ee8..f08f0b7bb 100644
--- a/kernel/indtypes.ml
+++ b/kernel/indtypes.ml
@@ -654,13 +654,12 @@ let compute_projections ((kn, _ as ind), u as indu) n x nparamargs params
       matching with a parameter context. *)
   let indty, paramsletsubst =
     let subst, inst = 
-      List.fold_right
-	(fun (na, b, t) (subst, inst) ->
+      List.fold_right_i
+	(fun i (na, b, t) (subst, inst) ->
 	 match b with
-	 | None -> (mkRel 1 :: List.map (lift 1) subst,
-		   mkRel 1 :: List.map (lift 1) inst)
-	 | Some b -> (substl subst b) :: subst, List.map (lift 1) inst)
-	paramslet ([], [])
+	 | None -> (mkRel i :: subst, mkRel i :: inst)
+	 | Some b -> (substl subst b) :: subst, inst)
+	1 paramslet ([], [])
     in
     let subst = (* For the record parameter: *)
       mkRel 1 :: List.map (lift 1) subst
@@ -690,8 +689,10 @@ let compute_projections ((kn, _ as ind), u as indu) n x nparamargs params
   in
   let projections (na, b, t) (i, j, kns, pbs, subst, letsubst) =
     match b with
-    | Some c -> (i, j+1, kns, pbs, substl subst c :: subst,
-		substl letsubst c :: subst)
+    | Some c ->
+        let c = liftn 1 j c in
+        (i, j+1, kns, pbs, substl subst c :: subst,
+         substl letsubst c :: letsubst)
     | None ->
       match na with
       | Name id ->
diff --git a/test-suite/success/primitiveproj.v b/test-suite/success/primitiveproj.v
index 125615c53..281d707cb 100644
--- a/test-suite/success/primitiveproj.v
+++ b/test-suite/success/primitiveproj.v
@@ -194,4 +194,17 @@ Record wrap (A : Type) := { unwrap : A; unwrap2 : A }.
 Definition term (x : wrap nat) := x.(unwrap).
 Definition term' (x : wrap nat) := let f := (@unwrap2 nat) in f x.
 Recursive Extraction term term'.
-(*Unset Printing Primitive Projection Parameters.*)
\ No newline at end of file
+(*Unset Printing Primitive Projection Parameters.*)
+
+(* Primitive projections in the presence of let-ins (was not failing in beta3)*)
+
+Set Primitive Projections.
+Record s (x:nat) (y:=S x) := {c:=x; d:x=c}.
+Lemma f : 0=1.
+Proof.
+Fail apply d.
+(*
+split.
+reflexivity.
+Qed.
+*)