Quickly fixing bug #2996: typing functions now check when referring to

a global reference that the current (goal) env contains all the
section variables that the global reference expects to be present.

Note that the test for inclusion might be costly: everytime a
conversion happens in a section variable copied in a goal, this
conversion has to be redone when referring to a constant dependent on
this section variable.

It is unclear to me whether we should not instead give global names to
section variables so that they exist even if they are not listed in
the context of the current goal.

Here are two examples which are still problematic:
Section A.
Let B := True : Type.
Definition C := eq_refl : B = True.
Theorem D : Type.
clearbody B.
set (x := C).
unfold C in x.
(* inconsistent context *)

or

Section A.
Let B : Type.
exact True.
Qed.
Definition C := eq_refl : B = True.  (* Note that this violated the Qed. *)
Theorem D : Type.
set (x := C).
unfold C in x.
(* inconsistent context *)

1 files changed, 1 insertions, 1 deletions

diff --git a/pretyping/pretyping.ml b/pretyping/pretyping.ml
index 6d7403031a..c8c1d0e213 100644
--- a/pretyping/pretyping.ml
+++ b/pretyping/pretyping.ml
@@ -311,7 +311,7 @@ let pretype_ref loc evdref env ref us =
   | ref ->
     let evd, c = pretype_global loc univ_flexible env !evdref ref us in
     let () = evdref := evd in
-    let ty = Retyping.get_type_of env evd c in
+    let ty = Typing.type_of env evd c in
       make_judge c ty
 
 let judge_of_Type evd s =