[lua] fix multireturn return type

src/generators/genlua.ml

@@ -260,19 +260,19 @@ let mk_mr_box ctx e =
     mk_lua_code ctx.com code [e] e.etype e.epos
 
 (* create a multi-return select call for given expr and field name *)
-let mk_mr_select com e name =
+let mk_mr_select com e ecall name =
     let i =
-        match follow e.etype with
+        match follow ecall.etype with
         | TInst (c,_) ->
             index_of (fun f -> f.cf_name = name) c.cl_ordered_fields
         | _ ->
             assert false
     in
     if i == 0 then
-        e
+        mk_lua_code com "{0}" [ecall] e.etype e.epos
     else
         let code = Printf.sprintf "_G.select(%i, {0})" (i + 1) in
-        mk_lua_code com code [e] e.etype e.epos
+        mk_lua_code com code [ecall] e.etype e.epos
 
 (* from genphp *)
 let rec is_string_type t =
@@ -1787,7 +1787,7 @@ let transform_multireturn ctx = function
                     (* if we found a field access for the multi-return call, generate select call *)
                     | TField ({ eexpr = TCall _ } as ecall, f) when is_multireturn ecall.etype ->
                         let ecall = Type.map_expr loop ecall in
-                        mk_mr_select ctx.com ecall (field_name f)
+                        mk_mr_select ctx.com e ecall (field_name f)
 
                     (* if we found a multi-return call used as a value, box it *)
                     | TCall _ when is_multireturn e.etype ->