Test interaction of subset field type ascription with type promotion …

…+ options.

test/test_subsets.ml

@@ -123,6 +123,20 @@ let tests = "subsets" >::: [
       }
       { Subset__h3.b = { Subset__h1.c = "bar" } }
   end;
+
+  "type promotion after field type ascription" >:: begin fun () ->
+    check_roundtrip
+      Subset__i1.pp Subset__i.write Subset__i1.read
+      { Subset__i.a = "foo"; b = 42 }
+      { Subset__i1.b = 42. }
+  end;
+
+  "type options after field type ascription" >:: begin fun () ->
+    check_roundtrip
+      Subset__j2.pp Subset__j1.write Subset__j2.read
+      { Subset__j1.a = Opt2.A 42; b = Opt2.A "foo" }
+      { Subset__j2.b = Some "foo" }
+  end;
 ]
 
 let () = Register_test.register "subsets"

test/test_types.proto

@@ -150,4 +150,12 @@ message subset__h1   = {| subset__h with c |}
 message subset__h2   = subset__h0<subset__h, subset__h, string>
 message subset__h3   = {| subset__h2 with b : subset__h1 |}
 
+message subset__i    = { a : string; b : int }
+message subset__i1   = {| subset__i with b : float |}
+
+type opt 'a = None | Some 'a options "ocaml.type_equals" = "option"
+type opt2 'a = B | A 'a
+message subset__j1   = { a : opt2<int>; b : opt2<string> }
+message subset__j2   = {| subset__j1 with b : opt<string> |}
+
 (* vim:set ft=ocaml: *)