Fix incorrect "avoid" set in globenv extra data

Fix #13348

2 files changed, 12 insertions, 1 deletions

diff --git a/engine/evarutil.ml b/engine/evarutil.ml
index 771571fd3f..ba6a9ea6d9 100644
--- a/engine/evarutil.ml
+++ b/engine/evarutil.ml
@@ -371,7 +371,8 @@ let push_rel_decl_to_named_context
       let subst = update_var id0 id subst in
       let d = decl |> NamedDecl.of_rel_decl (fun _ -> id0) |> map_decl (csubst_subst subst) in
       let nc = replace_var_named_declaration id0 id nc in
-      (push_var id0 subst, Id.Set.add id avoid, push_named_context_val d nc)
+      let avoid = Id.Set.add id (Id.Set.add id0 avoid) in
+      (push_var id0 subst, avoid, push_named_context_val d nc)
   | Some id0 when hypnaming = FailIfConflict ->
        user_err Pp.(Id.print id0 ++ str " is already used.")
   | _ ->
diff --git a/test-suite/bugs/closed/bug_13348.v b/test-suite/bugs/closed/bug_13348.v
new file mode 100644
index 0000000000..d3d5d3e5b4
--- /dev/null
+++ b/test-suite/bugs/closed/bug_13348.v
@@ -0,0 +1,10 @@
+Generalizable All Variables.
+
+Class Inhabited (A : Type) : Type := populate { inhabitant : A }.
+Arguments populate {_} _.
+
+Set Mangle Names.
+Axioms _0 _1 _2 : Prop.
+
+Instance impl_inhabited {A} {B} {_3:Inhabited B} : Inhabited (A -> B)
+  := populate (fun _ => inhabitant).