In this request: (https://issues.jenkins-ci.org/browse/JENKINS-28140), it asked for the ability to append to a custom field using the Jira Issue Updater plugin. This plugin requires a JQL to select the Jira issue to update. In some cases this does not work. On the other hand, the Jira-ext-plugin selects the Jira issue based on the Jira # mentioned in the commit comment. It would be nice to have the same append ability in the Jira-ext-plugin so the new value is appended instead of overriding the old value.
For example, I have a "Fixed in Version" custom field to indicate which versions the code is fixed in. The first time I build it in version 1.0, the "Fixed in Version" field is updated to 1.0. Then I build it again in version 1.1. But 1.1 will override 1.0. I'd like to show both 1.0 and 1.1 in the "Fixed in Version" field.