<!--IssueSummary start--> <details> <summary> Everyone can contribute. [Help move this issue forward](https://handbook.gitlab.com/handbook/marketing/developer-relations/contributor-success/community-contributors-workflows/#contributor-links) while earning points, leveling up and collecting rewards. </summary> - [Close this issue](https://contributors.gitlab.com/manage-issue?action=close&projectId=278964&issueIid=420795) </details> <!--IssueSummary end--> ### Summary When using [the 'Delete merged branches' functionality][docs], server hooks are invoked once per branch deleted. This is not only a performance issue, but if the hooks have side-effects (like sending an email), those side-effects are repeated for each branch instead of being batched together appropriately. [docs]: https://docs.gitlab.com/ee/user/project/repository/branches/#delete-merged-branches ### Steps to reproduce 1. Configure a pre-receive hook on a new project. For each branch in a push, perform some side-effect (post some logs, send an email, etc). 2. Create some number of branches directly on the mainline. 3. Use the 'Delete merged branches' functionality as described in [the docs][docs]. ### Example Project ```sh git init git commit --allow-empty -m "Initial commit" git push origin main:refs/heads/main seq 1 10 | xargs -L1 -I% echo git push origin main:refs/heads/branch-% ``` ### What is the current *bug* behavior? The pre-receive hook is invoked more than once with input of the form ``` deadbeef 0000000 refs/heads/branch-% ``` ### What is the expected *correct* behavior? The pre-receive hook is invoked exactly once with input of the form ``` deadbeef 0000000 refs/heads/branch-1 deadbeef 0000000 refs/heads/branch-2 deadbeef 0000000 refs/heads/branch-3 ... ``` ### Relevant logs and/or screenshots None available. ### Output of checks (Checking with the folks that maintain our gitlab instance for this section and below.) #### 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 <!-- Input any relevant GitLab application check information if needed. --> <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>