Use case:

• User is using the connector between Jira and Stash (or Bitbucket or Github) and wants the commits to show up in the issue.
• User is using the feature branch workflow and putting the Jira issue key into his branch names.
• User makes changes and starts commit in ST.
• Desired result: Jira issue key is automatically prefilled into the commit message.

Solution: Create a configuration option like "Prefill commit message from branch" which takes a regular expression as value. The part of the branch name that matches the expression gets extracted and put in the commit message. Note that the solution isn't hardcoded to Jira or Stash/Bitbucket/Github/..., and hence will work with other issue trackers or indeed any piece of information that can be sensibly copied from the branch name into the commit message.

See discussion at https://answers.atlassian.com/questions/16388104/how-to-get-the-issue-key-into-the-commit-message-automatically.