Merge commits are not linked to JIRA issues

Summary

• Merge commits, whose commit messages contain Jira issue keys, stopped displaying Jira issue keys in the Issues column.

Environment

• Bitbucket Server 5.4.0 integrated with Jira 7.3.1, using standard OAuth for authentication and having the consumer tokens created as usual.

Steps to Reproduce

1. Perform a merge commit
2. Go to the Commits page
3. See that no Jira issue key is presented next to the merge commit
4. See that no merge commit is shown in the Development panel of the Jira ticket.

Expected Results

• The Jira issue key shows up with a link to the actual issue in Jira side.
• The Development Panel in the Jira issue shows the merge commit.

Actual Results

• No Jira issue keys are presented next to the merge commit, as can be seen in the image attached.
• The merge commit is also not visible from JIRA, as can be seen in the image attached.
• No errors are written in the logs.

Notes

• This is working as expected in previous versions such as 5.1, 5.2 and 5.3, as can be seen in the images attached.

Workaround

• There is currently no workaround.