From 685643098eeef00fe1f8dfca0927db2e812e1e7a Mon Sep 17 00:00:00 2001
From: Hugo Herbelin
Date: Wed, 8 Nov 2017 19:58:41 +0100
Subject: One more step in fixing #5762 ("where" clause).

We improve one step further the heuristics to sort out if a variable
is a notation variable or a named variable.

This allows to support the following which was still failing.

Reserved Notation "# x" (at level 0).
Inductive I {A:Type} := C : # 0 -> I where "# I" := (I = I).

We rely here on the property that a binding variable of same name as a
notation variables is itself considered bound by the notation.

This becomes however to be a bit tricky for sorting out if the
variable has to be output to the glob file or not.
---
 interp/constrintern.ml          | 20 ++++++++++++--------
 test-suite/bugs/closed/5762.v   |  6 ++++++
 test-suite/success/Notations2.v |  6 ++++++
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/interp/constrintern.ml b/interp/constrintern.ml
index a0a749bfb3..e20a159f89 100644
--- a/interp/constrintern.ml
+++ b/interp/constrintern.ml
@@ -534,8 +534,9 @@ let traverse_binder (terms,_,_ as subst) avoid (renaming,env) = function
  | Name id ->
   try
     (* Binders bound in the notation are considered first-order objects *)
-    let _,na = coerce_to_name (fst (Id.Map.find id terms)) in
-    (renaming,{env with ids = Name.fold_right Id.Set.add na env.ids}), na
+    let _,na as locna = coerce_to_name (fst (Id.Map.find id terms)) in
+    let env = push_name_env Id.Map.empty (Variable,[],[],[]) env locna in
+    (renaming,env), na
   with Not_found ->
     (* Binders not bound in the notation do not capture variables *)
     (* outside the notation (i.e. in the substitution) *)
@@ -747,7 +748,14 @@ let gvar (loc, id) us = match us with
     str " cannot have a universe instance")
 
 let intern_var genv (ltacvars,ntnvars) namedctx loc id us =
-  (* Is [id] an inductive type potentially with implicit *)
+  (* Is [id] a notation variable *)
+  if Id.Map.mem id ntnvars then
+    begin
+      if not (Id.Map.mem id genv.impls) then set_var_scope ?loc id true genv ntnvars;
+      gvar (loc,id) us, [], [], []
+    end
+  else
+  (* Is [id] registered with implicit arguments *)
   try
     let ty,expl_impls,impls,argsc = Id.Map.find id genv.impls in
     let expl_impls = List.map
@@ -760,12 +768,8 @@ let intern_var genv (ltacvars,ntnvars) namedctx loc id us =
   if Id.Set.mem id genv.ids || Id.Set.mem id ltacvars.ltac_vars
   then
     gvar (loc,id) us, [], [], []
-  (* Is [id] a notation variable *)
-  else if Id.Map.mem id ntnvars
-  then
-    (set_var_scope ?loc id true genv ntnvars; gvar (loc,id) us, [], [], [])
-  (* Is [id] the special variable for recursive notations *)
   else if Id.equal id ldots_var
+  (* Is [id] the special variable for recursive notations? *)
   then if Id.Map.is_empty ntnvars
     then error_ldots_var ?loc
     else gvar (loc,id) us, [], [], []
diff --git a/test-suite/bugs/closed/5762.v b/test-suite/bugs/closed/5762.v
index edd5c8d73d..55d36bd722 100644
--- a/test-suite/bugs/closed/5762.v
+++ b/test-suite/bugs/closed/5762.v
@@ -26,3 +26,9 @@ Reserved Notation "%% a" (at level 70).
 Record R :=
   {g : forall {A} (a:A), a=a where "%% x" := (g x);
    k : %% 0 = eq_refl}.
+
+(* An extra example *)
+
+Module A.
+Inductive I {A:Type} := C : # 0 -> I where "# I" := (I = I) : I_scope.
+End A.
diff --git a/test-suite/success/Notations2.v b/test-suite/success/Notations2.v
index 9505a56e3f..e86b3edb83 100644
--- a/test-suite/success/Notations2.v
+++ b/test-suite/success/Notations2.v
@@ -90,3 +90,9 @@ Check fun A (x :prod' bool A) => match x with #### 0 y 0 => 2 | _ => 1 end.
 Notation "##### x" := (pair' x) (at level 0, x at level 1).
 Check ##### 0 _ 0%bool 0%bool : prod' bool bool.
 Check fun A (x :prod' bool A) => match x with ##### 0 _ y 0%bool => 2 | _ => 1 end.
+
+(* 10. Check computation of binding variable through other notations *)
+(* i should be detected as binding variable and the scopes not being checked *)
+
+Notation "'FUNNAT' i => t" := (fun i : nat => i = t) (at level 200).
+Notation "'Funnat' i => t" := (FUNNAT i => t + i%nat) (at level 200).
-- 
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