jenkinsci/git-plugin — pull request #78 by tsondergaard (2012-07-28 12:11:52+00:00)
Title: Better changelog for jobs with a merge target

If a job is configured to build multiple branches and have a merge target, the changelog should not be computed relative to an earlier build of this branch - especially as there will typically not be an earlier branch. Instead the changelog should be computed relative to the merge target, such that the changes show what is merged.

Note that since the changelog is also used to determine who to send email to it becomes especially relevant that this mechanism also works for newborn branches.