Issue Summary

When merging a pull request through the UI, the merge may appear to fail with a "Something went wrong" error. However, the merge will have been made in the repository even though the pull request remains open.

Steps to Reproduce

1. Merge a pull request with "Close source branch" checked in the merge dialog

This behavior is intermittent and rare, so it will be difficult to reproduce consistently.

Expected Results

The pull request is marked merged, the source branch is merged into the destination branch, and the source branch is closed.

Actual Results

The source branch is merged into the destination branch, but is not closed, and the pull request is not marked as merged.

Workaround

Pushing or merging an additional commit into either the source or destination branch of the pull request should cause Bitbucket to detect the merge and update the pull request.