Description

Fixes#11670

Fixed a bug where getVersion() threw a NullPointerException when called for an item without a version. The method now safely checks for null before accessing version history and returns null instead of throwing an error. Added a unit test to cover this case and prevent future regressions.

Instructions for Reviewers

Verify null check in VersionHistoryServiceImpl.getVersion() prevents NPE
Confirm method returns null gracefully for items without versions
Check new test testGetVersionWithNullPointerException() covers the bug scenario
Run new unit test (should pass)

Checklist

This checklist provides a reminder of what we are going to look for when reviewing your PR. You need not complete this checklist prior to creating your PR (draft PRs are always welcome).
However, reviewers may request that you complete any actions in this list if you have not done so. If you are unsure about an item in the checklist, don't hesitate to ask. We're here to help!

• My PR iscreated against themain branch of code (unless it is a backport or is fixing an issue specific to an older branch).
• My PR issmall in size (e.g. less than 1,000 lines of code, not including comments & integration tests). Exceptions may be made if previously agreed upon.
• My PRpasses Checkstyle validation based on theCode Style Guide.
• My PRincludes Javadoc forall new (or modified) public methods and classes. It also includes Javadoc for large or complex private methods.
• My PRpasses all tests and includes new/updated Unit or Integration Tests based on theCode Testing Guide.
• My PRincludes details on how to test it. I've provided clear instructions to reviewers on how to successfully test this fix or feature.
• If my PR includes new libraries/dependencies (in anypom.xml), I've made sure their licenses align with theDSpace BSD License based on theLicensing of Contributions documentation.
• If my PR modifies REST API endpoints, I've opened a separateREST Contract PR related to this change.
• If my PR includes new configurations, I've provided basic technical documentation in the PR itself.
• If my PR fixes an issue ticket, I'velinked them together.