Eclipse Jira Connector deletes data from custom field with multiple data

When I use the Eclipse connector to submit the time spent in an issue, the connector behaves in strange way with custom fields that sore multiple data (Multiple Select, etc).
For instance if an issue has a custom field with these values: AAAA,BBBB,CCCC, after submitting the time spent using the connector the issue will have only the last value: CCCC.
This happens with all custom fields (that store multiple data) in the issue.
If the custom field has got only one value, this won't be affected.

A user has proposed a fix to the connector

http://bitbucket09.managed.contegix.com/atlassian/connector-eclipse/pull-request/1/fix-update-issue-with-custom-fields

Please, can you solve it?

Thanks