1.环境
ubuntu16.04 gerrit
2.问题
在gerrit上提交代码，在patch未合并之前，本地文件丢失，从远程下载后继续修改，
并提交到之前的repository.
3.解决方法
3.1.create a floder(where the remote patch will locate), and run "git init" in this new floder.
3.2.configure remote repository. run "git remote add gerrit https://Launchpad_id@review.openstack.org/openstack/tricircle.git"
(Launchpad_id is your own launchpad id)
3.3.download the remote patch. run "git review -d patch_number".
3.4.then the remote files are downloaded to local respository. Just like the beginning of the your development. edit it as you planned.
3.5.run "git add .".
3.6.run "git commit -a --amend".
3.7.run "git review".
(其中，如果在其他机器上操作，需要配置user.name 和user.email。在自己的机器上，会用已配置好的。branch也会用已配置的。git review需要HTTP password for Launchpad_id.此密码不是launchpad邮箱账号的密码，登录github，有HTTP password，即是该密码)