Cause:

在 Gerrit 等待 code review 通過期間，若有協同開發者先 merge commit ,且該 commit 和 自己的commit 發生衝突的情況

Solution:

1.
在發生conflict 的 branch上 執行
git pull --rebase origin master
此指令說明如下
This command will fetch new commits from the remote and then rebase your local commits on top of them. It will temporarily set aside the changes you’ve made in your branch, apply all of the changes that have happend in master to your working branch, then merge (recommit) all of the changes you’ve made back into the branch. Doing this will help avoid future merge conflicts. Plus, it gives you an opportunity to test your changes against the latest code in master.
Once you are satisfied with your change set and you’ve rebased against master, you are ready to push your code to Gerrit for review.
簡單的說：把master上已合併的commit(但在目前branch不存在),接到目前的branch上,再把
目前branch的commit接到最後面（最新）
當然在Gerrit 網頁上合併會發生衝突,所以執行這個指令之後在本地端也會發生衝突,
把執行後的提示紀錄下來如下
When you have resolved this problem run "git rebase --continue".
If you would prefer to skip this patch, instead run "git rebase --skip".
To check out the original branch and stop rebasing run "git rebase –abort".
接下來的步驟為
2. 修改發生衝突的地方,使用vim修改
3. 把修改後的檔案全部 git add
4. git add 所有的檔案之後執行 git rebase –continue
5. 最後 git push origin HEAD:refs/for/master
6. 必須重新等待code review