Merge branch 'master' into 'dev'

# Conflicts:
#   SystemUpdater/backend/__init__.py

SystemUpdater/backend/__init__.py

@@ -105,12 +105,17 @@ class InstallBackend():
             return new_pkgs_install,new_pkgs_upgrade,new_pkgs_remove
         except Exception as e:
             logging.error(e)
+            return [],[],[]
 
     def start(self,partial_upgrade_list = []):
         #FIXME: 在下载升级的能抑制系统关闭或者睡眠 参考ubuntu此部分代码
 
         if self.action == self.ACTION_INSTALL:
             pkgs_install,pkgs_upgrade,pkgs_remove = self._make_problem_resolver(partial_upgrade_list)
+            
+            if not pkgs_install and not pkgs_upgrade and not pkgs_remove:
+                return
+            
             try:
                 logging.info("commit install:%d , upgrade:%d remove:%d",len(pkgs_install),len(pkgs_upgrade),len(pkgs_remove))
                 self.commit(pkgs_install, pkgs_upgrade, pkgs_remove)