RFR: 1715: Configure custom default security level for new backport issues in notifier

[Zhao Song]

On Thu, 15 Dec 2022 22:12:29 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

> This patch makes it possible to configure a default security level to use for any newly created backport in the IssueNotifier. The configuration is done per repository and branch, with a regex for matching branch names. This is what it would look like in the bot configuration.
> 
> 
> "issue": {
>   "project": "bugs/JDK",
>   "fixversions": {},
>   "buildname": "master",
>   "headversion": true,
>   "defaultsecurity": {  // <- new
>     "jdk.*": "10000",
>   }
> }
> 
> 
> If the parent bug already has a security level, then that is inherited, just like today, otherwise this new default value is used.

LGTM! The test is very clear and well-organized.

-------------

Marked as reviewed by zsong (Committer).

PR: https://git.openjdk.org/skara/pull/1445