Issue Summary

When a Jira Cloud instance has a blank application title (in General Configuration), Bitbucket DC 10.2.4 allows the application tunnel setup to proceed without any validation or warning. The connection test passes successfully. However, subsequent operations on the established link fail with a 500 Internal Server Error due to a NullPointerException caused by title=null.

Steps to Reproduce

1. Ensure the Jira Cloud instance has a blank application title in General Configuration (Administration >General Configuration >Application Title is empty)
2. In Bitbucket Data Center 10.2.4, set up an application tunnel to the Jira Cloud instance.
3. Complete the tunnel setup, connection test passes successfully.
4. Attempt to edit the application link in Bitbucket DC.
5. Alternatively, click on a Jira issue ID in a Bitbucket commit message

Expected Results

• Bitbucket should validate that the Jira Cloud application title is not blank during tunnel setup and either block the setup or display a warning to the user

• If the link is established, editing the link and clicking Jira IDs should function correctly

Actual Results

• Bitbucket allows the tunnel setup to complete without any warning about the blank application title.
• Editing the application link in Bitbucket results in a 500 Internal Server Error.
• Clicking on Jira issue IDs in Bitbucket commit messages also results in a 500 Internal Server Error.

The below exception is thrown in the atlassian-bitbucket.log file:

java.lang.NullPointerException
    ... (title=null)

Workaround

Set the application title in the Jira Cloud instance's General Configuration following https://support.atlassian.com/jira-cloud-administration/docs/change-the-application-title/, then re-test the connection in Bitbucket. After this, the link becomes editable and Jira IDs in commit messages work as expected.