From 4e912c8961af5a9826638a461818b64eaa3cac59 Mon Sep 17 00:00:00 2001
From: SimonBoulier
Date: Tue, 10 Mar 2020 15:45:49 +0100
Subject: Remove a positivity check when Check Positivity is off

---
 kernel/indtypes.ml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/indtypes.ml b/kernel/indtypes.ml
index b6b8e5265c..253c308974 100644
--- a/kernel/indtypes.ml
+++ b/kernel/indtypes.ml
@@ -102,7 +102,7 @@ let failwith_non_pos_list n ntypes l =
 
 (* Check the inductive type is called with the expected parameters *)
 (* [n] is the index of the last inductive type in [env] *)
-let check_correct_par (env,n,ntypes,_) paramdecls ind_index args =
+let check_correct_par ~chkpos (env,n,ntypes,_) paramdecls ind_index args =
   let nparams = Context.Rel.nhyps paramdecls in
   let args = Array.of_list args in
   if Array.length args < nparams then
@@ -123,7 +123,7 @@ let check_correct_par (env,n,ntypes,_) paramdecls ind_index args =
               LocalNonPar (param_index+1, paramdecl_index_in_env, ind_index) in
             raise (IllFormedInd err)
   in check (nparams-1) (n-nparamdecls) paramdecls;
-  if not (Array.for_all (noccur_between n ntypes) realargs) then
+  if chkpos && not (Array.for_all (noccur_between n ntypes) realargs) then
     failwith_non_pos_vect n ntypes realargs
 
 (* Computes the maximum number of recursive parameters:
@@ -325,7 +325,7 @@ let check_positivity_one ~chkpos recursive (env,_,ntypes,_ as ienv) paramsctxt (
               if check_head then
                 begin match hd with
                 | Rel j when Int.equal j (n + ntypes - i - 1) ->
-                  check_correct_par ienv paramsctxt (ntypes - i) largs
+                  check_correct_par ~chkpos ienv paramsctxt (ntypes - i) largs
                 | _ -> raise (IllFormedInd (LocalNotConstructor(paramsctxt,nnonrecargs)))
                 end
               else
-- 
cgit v1.2.3


From a35e7f9143c8b1c3928978e3b8edc5b326e1f854 Mon Sep 17 00:00:00 2001
From: SimonBoulier
Date: Thu, 12 Mar 2020 10:39:03 +0100
Subject: Add changelog entry

---
 doc/changelog/01-kernel/11811-uncheck_positivity_bug.rst | 4 ++++
 1 file changed, 4 insertions(+)
 create mode 100644 doc/changelog/01-kernel/11811-uncheck_positivity_bug.rst

diff --git a/doc/changelog/01-kernel/11811-uncheck_positivity_bug.rst b/doc/changelog/01-kernel/11811-uncheck_positivity_bug.rst
new file mode 100644
index 0000000000..c08ebb7f25
--- /dev/null
+++ b/doc/changelog/01-kernel/11811-uncheck_positivity_bug.rst
@@ -0,0 +1,4 @@
+- **Fixed:**
+  Allow more inductive types in `Unset Positivity Checking` mode
+  (`#11811 <https://github.com/coq/coq/pull/11811>`_,
+  by SimonBoulier).
-- 
cgit v1.2.3


From b62a6df9907169f47a72ee78ebe088c68932dd93 Mon Sep 17 00:00:00 2001
From: SimonBoulier
Date: Tue, 17 Mar 2020 10:20:50 +0100
Subject: Add test for PR11811 (disable a positivity check)

---
 test-suite/bugs/closed/bug_11811.v | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 test-suite/bugs/closed/bug_11811.v

diff --git a/test-suite/bugs/closed/bug_11811.v b/test-suite/bugs/closed/bug_11811.v
new file mode 100644
index 0000000000..a73494b630
--- /dev/null
+++ b/test-suite/bugs/closed/bug_11811.v
@@ -0,0 +1,13 @@
+
+Unset Positivity Checking.
+
+Inductive foo : Type -> Type :=
+| bar : foo (foo unit)
+| baz : foo nat.
+
+Definition toto : forall A, foo A -> {A = foo unit} + {A = nat}.
+Proof.
+  intros A x. destruct x; intuition.
+Defined.
+
+Check (eq_refl : toto _ baz = right eq_refl).
-- 
cgit v1.2.3