From 5b3e47334d2e6985d61e5d8abaac87cc23af507d Mon Sep 17 00:00:00 2001
From: ygl <ygl@rgi5.com>
Date: Tue, 1 Nov 2016 14:06:20 +0800
Subject: [PATCH] better error handling

---
 _sqlite3.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/_sqlite3.py b/_sqlite3.py
index 59698a0..1816275 100644
--- a/_sqlite3.py
+++ b/_sqlite3.py
@@ -655,13 +655,16 @@ class Connection(object):
     def backup(self, target_conn_obj):
         db_name = _ffi.new("char []", "main")
         bk_obj = _lib.sqlite3_backup_init(target_conn_obj._db, db_name, self._db, db_name)
-        if bk_obj:
+        if bk_obj != _ffi.NULL:
             rc = _lib.SQLITE_OK
             while rc == _lib.SQLITE_OK or rc == _lib.SQLITE_BUSY or rc == _lib.SQLITE_LOCKED:
                 rc = _lib.sqlite3_backup_step(bk_obj, 100)
                 if rc == _lib.SQLITE_OK or rc == _lib.SQLITE_BUSY or rc == _lib.SQLITE_LOCKED:
                     _lib.sqlite3_sleep(5)
-            _lib.sqlite3_backup_finish(bk_obj)
+            if rc != _lib.SQLITE_DONE:
+                raise self._get_exception(rc)
+            else:
+                _lib.sqlite3_backup_finish(bk_obj)
 
 
 class Cursor(object):