<!--- Please read this! Before opening a new issue, make sure to search for keywords in the issues filtered by the "regression" or "bug" label: - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=regression - https://gitlab.com/gitlab-org/gitlab/issues?label_name%5B%5D=bug and verify the issue you're about to submit isn't a duplicate. ---> ### Summary (Summarize the bug encountered concisely) ### Steps to reproduce - Have a repo with the default branch `master`. - Add some commits. - Create a `fix-1` branch. - Add some commits. - Create a `fix-2` branch from `fix-1`. - Add some commits. - Merge the `fix-2` branch into `fix-1`. - Create a request for merging `fix-1` into `master`. - Add some commits to `master`. ### Example Project (If possible, please create an example project here on GitLab.com that exhibits the problematic behavior, and link to it here in the bug report) (If you are using an older version of GitLab, this will also determine whether the bug is fixed in a more recent version) ### What is the current *bug* behavior? A rebase button shows up in the MR. ### What is the expected *correct* behavior? As far as I know, the rebase won't work when the branch contains merges. ### Relevant logs and/or screenshots (Paste any relevant logs - please use code blocks (```) to format console output, logs, and code as it's tough to read otherwise.) ### Output of checks This bug happens on GitLab.com #### Results of GitLab environment info <details> <summary>Expand for output related to GitLab environment info</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`) </pre> </details> #### Results of GitLab application Check <details> <summary>Expand for output related to the GitLab application check</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:check SANITIZE=true`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true`) (we will only investigate if the tests are passing) </pre> </details> ### Possible fixes * We need to teach git-replay(1) to deal with merges: https://gitlab.com/gitlab-org/git/-/issues/384 * We need to teach Gitaly to use git-replay(1): https://gitlab.com/gitlab-org/gitaly/-/issues/5716