1 files changed, 75 insertions, 0 deletions
diff --git a/test-suite/bugs/closed/3685.v b/test-suite/bugs/closed/3685.v
new file mode 100644
index 00000000..a5bea34a
--- /dev/null
+++ b/test-suite/bugs/closed/3685.v
@@ -0,0 +1,75 @@
+Require Import TestSuite.admit.
+Set Universe Polymorphism.
+Class Funext := { }.
+Delimit Scope category_scope with category.
+Record PreCategory := { object :> Type ; morphism : object -> object -> Type }.
+Set Implicit Arguments.
+Record Functor (C D : PreCategory) :=
+  { object_of :> C -> D;
+    morphism_of : forall s d, morphism C s d -> morphism D (object_of s) (object_of d);
+    identity_of : forall s m, morphism_of s s m = morphism_of s s m }.
+Definition sub_pre_cat `{Funext} (P : PreCategory -> Type) : PreCategory.
+Proof.
+  exact (@Build_PreCategory PreCategory Functor).
+Defined.
+Definition opposite (C : PreCategory) : PreCategory.
+Proof.
+  exact (@Build_PreCategory C (fun s d => morphism C d s)).
+Defined.
+Local Notation "C ^op" := (opposite C) (at level 3, format "C '^op'") : category_scope.
+Definition prod (C D : PreCategory) : PreCategory.
+Proof.
+  refine (@Build_PreCategory
+            (C * D)%type
+            (fun s d => (morphism C (fst s) (fst d) * morphism D (snd s) (snd d))%type)).
+Defined.
+Local Infix "*" := prod : category_scope.
+Record NaturalTransformation C D (F G : Functor C D) := {}.
+Definition functor_category (C D : PreCategory) : PreCategory.
+Proof.
+  exact (@Build_PreCategory (Functor C D) (@NaturalTransformation C D)).
+Defined.
+Local Notation "C -> D" := (functor_category C D) : category_scope.
+Module Export PointwiseCore.
+  Local Open Scope category_scope.
+  Definition pointwise
+             (C C' : PreCategory)
+             (F : Functor C' C)
+             (D D' : PreCategory)
+             (G : Functor D D')
+  : Functor (C -> D) (C' -> D').
+  Proof.
+    refine (Build_Functor
+              (C -> D) (C' -> D')
+              _
+              _
+              _);
+    abstract admit.
+  Defined.
+End PointwiseCore.
+Axiom Pidentity_of : forall (C D : PreCategory) (F : Functor C C) (G : Functor D D), pointwise F G = pointwise F G.
+Local Open Scope category_scope.
+Module Success.
+  Definition functor_uncurried `{Funext} (P : PreCategory -> Type)
+             (has_functor_categories : forall C D : sub_pre_cat P, P (C -> D))
+  : object (((sub_pre_cat P)^op * (sub_pre_cat P)) -> (sub_pre_cat P))
+    := Eval cbv zeta in
+        let object_of := (fun CD => (((fst CD) -> (snd CD))))
+        in Build_Functor
+             ((sub_pre_cat P)^op * (sub_pre_cat P)) (sub_pre_cat P)
+             object_of
+             (fun CD C'D' FG => pointwise (fst FG) (snd FG))
+             (fun _ _ => @Pidentity_of _ _ _ _).
+End Success.
+Module Bad.
+  Include PointwiseCore.
+  Definition functor_uncurried `{Funext} (P : PreCategory -> Type)
+             (has_functor_categories : forall C D : sub_pre_cat P, P (C -> D))
+  : object (((sub_pre_cat P)^op * (sub_pre_cat P)) -> (sub_pre_cat P))
+    := Eval cbv zeta in
+        let object_of := (fun CD => (((fst CD) -> (snd CD))))
+        in Build_Functor
+             ((sub_pre_cat P)^op * (sub_pre_cat P)) (sub_pre_cat P)
+             object_of
+             (fun CD C'D' FG => pointwise (fst FG) (snd FG))
+             (fun _ _ => @Pidentity_of _ _ _ _).