From 422396cecef271e4c40e4654a7b5af1208e28a92 Mon Sep 17 00:00:00 2001
From: Paul Sokolovsky <pfalcon@users.sourceforge.net>
Date: Wed, 15 Jun 2016 04:17:45 +0300
Subject: [PATCH] extmod/modbtree: Handle default value and error check.

---
 extmod/modbtree.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/extmod/modbtree.c b/extmod/modbtree.c
index 4dd7da3b2d..58212b33ad 100644
--- a/extmod/modbtree.c
+++ b/extmod/modbtree.c
@@ -92,8 +92,13 @@ STATIC mp_obj_t btree_get(size_t n_args, const mp_obj_t *args) {
     key.data = (void*)mp_obj_str_get_data(args[1], &key.size);
     int res = __bt_get(self->db, &key, &val, 0);
     if (res == RET_SPECIAL) {
-        return mp_const_none;
+        if (n_args > 2) {
+            return args[2];
+        } else {
+            return mp_const_none;
+        }
     }
+    CHECK_ERROR(res);
     return mp_obj_new_bytes(val.data, val.size);
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(btree_get_obj, 2, 3, btree_get);