git：重置分支吞噬主分支

Question

My git history gets something wrong. One of the branches steal master branch commits when I use some commands below:

$ git clone [repo_url]
$ git checkout [branch_A_name]  -- This branch has a commit
$ git reset --soft [revision_hash]   -- same as HEAD~1
$ git add [some_files]
$ git commit
$ git push -f

After this, I found some commits that I already merged to master branch is stolen by branch_A , which I force-pushed just right before. These diffs are removed from master .

Actually, this is not mine. My teammates are in this situation and I heard they haven't used git rebase .
They just did reset - commit - force push and they saw a messed up tree in their pull request page.

We use bitbucket. Thank you.

Answer 1

From what I can understand your teammate probably did

git reset  --<probably hard> master
<made changes>
git add <changes>
git commit -m <“message”>
git push -f <whatever> 

While this process will work in some situations it will not work in others. It's my guess that your teammate let their branch get out of date by not performing git pull on the master or by doing git remote -v update to get the latest changes before the push. He then did a git reset --<whatever> to update and force pushed the branch. This means that the commit history they pushed diverged from the master in more ways than just the commit they wanted to change and other commits may show up there.

To fix this situation they need to

git checkout master
git pull
git checkout feature branch
git rebase <master or origin/master>
git log 
<check if commits are correct in the log>
git diff --name-only origin/master
<check if only his commit appears>
git push -f origin <branch name> 

Additionally if you are using Forks on Atlassian there is a potential for another situation - their fork is unsynced. Though Atlassian forks are usually set up to auto-sync, a git push -f without specifying the branch name can go rogue between an outdated local repository and a fork. Make sure that the commit history on their master is the same as the one on the main repo and that they unchecked and recheckard the “automatic sync” button in settings. Make sure it says that it was last synced a moment ago. From there they'll need to update their local and all that good stuff.