Make future_goals stack explicit in the evarmap

1 files changed, 3 insertions, 2 deletions

diff --git a/vernac/classes.ml b/vernac/classes.ml
index f454c389dc..5423504f71 100644
--- a/vernac/classes.ml
+++ b/vernac/classes.ml
@@ -358,8 +358,9 @@ let declare_instance_open sigma ?hook ~tac ~global ~poly id pri impargs udecl id
      the pretyping after the proof has opened. As a
      consequence, we use the low-level primitives to code
      the refinement manually.*)
-  let gls = List.rev (Evd.future_goals sigma) in
-  let sigma = Evd.reset_future_goals sigma in
+  let future_goals, sigma = Evd.pop_future_goals sigma in
+  let gls = List.rev_append future_goals.Evd.future_shelf (List.rev future_goals.Evd.future_comb) in
+  let sigma = Evd.push_future_goals sigma in
   let kind = Decls.(IsDefinition Instance) in
   let hook = Declare.Hook.(make (fun { S.dref ; _ } -> instance_hook pri global ?hook dref)) in
   let info = Declare.Info.make ~hook ~kind ~udecl ~poly () in