Javadoc
Abort this ChangelogCommand without executing it, close any
open resources. The JGit implementation of changelog
calculation opens the git repository and will close it when the
changelog.execute() is processed. However, there are cases
(like GitSCM.computeChangeLog) which create a changelog and
never call execute().
Either execute() or abort() must be called for each
ChangelogCommand instance or files will be left open.