From 6140c07555d630e86b43024744a39316400d9882 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulysse=20G=C3=A9rard?= <thevoodoos@gmail.com>
Date: Tue, 21 Nov 2023 11:55:46 +0100
Subject: [PATCH 1/3] Add a test illustrating #1704

(cherry picked from commit 81a05bde46650032ffbe220152f187731b00bcdd)
---
 .../errors/issue1704-wrong-message.t          | 104 ++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 tests/test-dirs/errors/issue1704-wrong-message.t

diff --git a/tests/test-dirs/errors/issue1704-wrong-message.t b/tests/test-dirs/errors/issue1704-wrong-message.t
new file mode 100644
index 000000000..d10783eff
--- /dev/null
+++ b/tests/test-dirs/errors/issue1704-wrong-message.t
@@ -0,0 +1,104 @@
+  $ cat >test.ml <<'EOF'
+  > type foo = {
+  >   bar: X.t;
+  > }
+  > type foo2 = X.t
+  > type foo3 = bar
+  > EOF
+
+FIXME:Merlin should not report unbound variable errors in that case since it is
+due to it's own type recovery.
+  $ $MERLIN single errors -filename test.ml <test.ml 
+  {
+    "class": "return",
+    "value": [
+      {
+        "start": {
+          "line": 1,
+          "col": 0
+        },
+        "end": {
+          "line": 3,
+          "col": 1
+        },
+        "type": "typer",
+        "sub": [],
+        "valid": true,
+        "message": "A type variable is unbound in this type declaration.
+  In field bar: 'a the variable 'a is unbound"
+      },
+      {
+        "start": {
+          "line": 2,
+          "col": 7
+        },
+        "end": {
+          "line": 2,
+          "col": 10
+        },
+        "type": "typer",
+        "sub": [],
+        "valid": true,
+        "message": "Unbound module X"
+      },
+      {
+        "start": {
+          "line": 4,
+          "col": 0
+        },
+        "end": {
+          "line": 4,
+          "col": 15
+        },
+        "type": "typer",
+        "sub": [],
+        "valid": true,
+        "message": "A type variable is unbound in this type declaration.
+  In type 'a the variable 'a is unbound"
+      },
+      {
+        "start": {
+          "line": 4,
+          "col": 12
+        },
+        "end": {
+          "line": 4,
+          "col": 15
+        },
+        "type": "typer",
+        "sub": [],
+        "valid": true,
+        "message": "Unbound module X"
+      },
+      {
+        "start": {
+          "line": 5,
+          "col": 0
+        },
+        "end": {
+          "line": 5,
+          "col": 15
+        },
+        "type": "typer",
+        "sub": [],
+        "valid": true,
+        "message": "A type variable is unbound in this type declaration.
+  In type 'a the variable 'a is unbound"
+      },
+      {
+        "start": {
+          "line": 5,
+          "col": 12
+        },
+        "end": {
+          "line": 5,
+          "col": 15
+        },
+        "type": "typer",
+        "sub": [],
+        "valid": true,
+        "message": "Unbound type constructor bar"
+      }
+    ],
+    "notifications": []
+  }

From 17e5b1d9610cc1108a6a05a24510f113acb5b004 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ulysse=20G=C3=A9rard?= <thevoodoos@gmail.com>
Date: Tue, 21 Nov 2023 14:07:50 +0100
Subject: [PATCH 2/3] Fix issue #1704 by correctly registering erroneous types

Co-authored-by: Thomas Refis <thomas.refis@gmail.com>
(cherry picked from commit c05f3a35f9de2271aa44b2db601040e2154a87a8)
---
 src/ocaml/typing/typedecl.ml                  |  4 +-
 src/ocaml/typing/typetexp.ml                  |  7 +++
 .../errors/issue1704-wrong-message.t          | 47 +------------------
 3 files changed, 11 insertions(+), 47 deletions(-)

diff --git a/src/ocaml/typing/typedecl.ml b/src/ocaml/typing/typedecl.ml
index 50594434f..ebbac722b 100644
--- a/src/ocaml/typing/typedecl.ml
+++ b/src/ocaml/typing/typedecl.ml
@@ -1955,7 +1955,9 @@ let transl_type_decl env rec_flag sdecl_list =
     (fun sdecl tdecl ->
       let decl = tdecl.typ_type in
        match Ctype.closed_type_decl decl with
-         Some ty -> raise(Error(sdecl.ptype_loc, Unbound_type_var(ty,decl)))
+         Some ty ->
+          if not (Msupport.erroneous_type_check ty) then
+            raise(Error(sdecl.ptype_loc, Unbound_type_var(ty,decl)))
        | None   -> ())
     sdecl_list tdecls;
   (* Check that constraints are enforced *)
diff --git a/src/ocaml/typing/typetexp.ml b/src/ocaml/typing/typetexp.ml
index 132f60f05..2b3f24a47 100644
--- a/src/ocaml/typing/typetexp.ml
+++ b/src/ocaml/typing/typetexp.ml
@@ -644,9 +644,16 @@ let rec transl_type env ~policy ?(aliased=false) ~row_context mode styp =
        try
          transl_type_aux env ~policy ~aliased ~row_context mode styp
        with exn ->
+         let ty = new_global_var () in
+         Msupport.erroneous_type_register ty;
          Msupport.raise_error exn;
+<<<<<<< HEAD
            { ctyp_desc = Ttyp_var (None, None);
              ctyp_type = new_global_var (Jkind.value ~why:(Unknown "merlin"));
+=======
+           { ctyp_desc = Ttyp_any;
+             ctyp_type = ty;
+>>>>>>> c05f3a35... Fix issue #1704 by correctly registering erroneous types
              ctyp_env = env;
              ctyp_loc = styp.ptyp_loc;
              ctyp_attributes = [];
diff --git a/tests/test-dirs/errors/issue1704-wrong-message.t b/tests/test-dirs/errors/issue1704-wrong-message.t
index d10783eff..b6e7faa11 100644
--- a/tests/test-dirs/errors/issue1704-wrong-message.t
+++ b/tests/test-dirs/errors/issue1704-wrong-message.t
@@ -6,27 +6,12 @@
   > type foo3 = bar
   > EOF
 
-FIXME:Merlin should not report unbound variable errors in that case since it is
+Merlin should not report unbound variable errors in that case since it is
 due to it's own type recovery.
   $ $MERLIN single errors -filename test.ml <test.ml 
   {
     "class": "return",
     "value": [
-      {
-        "start": {
-          "line": 1,
-          "col": 0
-        },
-        "end": {
-          "line": 3,
-          "col": 1
-        },
-        "type": "typer",
-        "sub": [],
-        "valid": true,
-        "message": "A type variable is unbound in this type declaration.
-  In field bar: 'a the variable 'a is unbound"
-      },
       {
         "start": {
           "line": 2,
@@ -41,21 +26,6 @@ due to it's own type recovery.
         "valid": true,
         "message": "Unbound module X"
       },
-      {
-        "start": {
-          "line": 4,
-          "col": 0
-        },
-        "end": {
-          "line": 4,
-          "col": 15
-        },
-        "type": "typer",
-        "sub": [],
-        "valid": true,
-        "message": "A type variable is unbound in this type declaration.
-  In type 'a the variable 'a is unbound"
-      },
       {
         "start": {
           "line": 4,
@@ -70,21 +40,6 @@ due to it's own type recovery.
         "valid": true,
         "message": "Unbound module X"
       },
-      {
-        "start": {
-          "line": 5,
-          "col": 0
-        },
-        "end": {
-          "line": 5,
-          "col": 15
-        },
-        "type": "typer",
-        "sub": [],
-        "valid": true,
-        "message": "A type variable is unbound in this type declaration.
-  In type 'a the variable 'a is unbound"
-      },
       {
         "start": {
           "line": 5,

From d5b67572ba5ce4f3403acddfdc1920ab6a8b7e83 Mon Sep 17 00:00:00 2001
From: Nick Roberts <nroberts02@gmail.com>
Date: Mon, 29 Apr 2024 11:13:07 -0400
Subject: [PATCH 3/3] Fix merge conflicts from backport

---
 src/ocaml/typing/typetexp.ml | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/src/ocaml/typing/typetexp.ml b/src/ocaml/typing/typetexp.ml
index 2b3f24a47..3bf96633b 100644
--- a/src/ocaml/typing/typetexp.ml
+++ b/src/ocaml/typing/typetexp.ml
@@ -644,16 +644,11 @@ let rec transl_type env ~policy ?(aliased=false) ~row_context mode styp =
        try
          transl_type_aux env ~policy ~aliased ~row_context mode styp
        with exn ->
-         let ty = new_global_var () in
+         let ty = new_global_var (Jkind.value ~why:(Unknown "merlin")) in
          Msupport.erroneous_type_register ty;
          Msupport.raise_error exn;
-<<<<<<< HEAD
            { ctyp_desc = Ttyp_var (None, None);
-             ctyp_type = new_global_var (Jkind.value ~why:(Unknown "merlin"));
-=======
-           { ctyp_desc = Ttyp_any;
              ctyp_type = ty;
->>>>>>> c05f3a35... Fix issue #1704 by correctly registering erroneous types
              ctyp_env = env;
              ctyp_loc = styp.ptyp_loc;
              ctyp_attributes = [];