RFR: backports: handle original commit without issues

[Robin Westberg]

On Wed, 20 Jan 2021 13:07:55 GMT, Erik Helin <ehelin at openjdk.org> wrote:

> Hi all,
> 
> please review this patch that handles backports of commits that are missing proper references to issues in JBS.
> 
> Testing:
> - [x] Added a new unit test
> 
> Thanks,
> Erik

Looks good!

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Marked as reviewed by rwestberg (Reviewer).

PR: https://git.openjdk.java.net/skara/pull/986