I was able to test the functionality (which seemed to work fine) and fed in my comment to assist anyone else reviewing this patch (and intentionally let it's state as 'Needs Review').
While trying to provide my feedback, on hindsight I should have been more detailed about what I didn't test. Being my first review, I didn't understand that not checking a box meant 'failure'. For e.g. I read the sgml changes, which felt okay but didn't click 'Passed' because my env wasn't setup properly.
Hmmm, ISTM that it was enough. The feature is psql specific, so the fact that it works against a 9.6 server is both expected and fine. So ISTM that your test "passed".
Just running "make check" would run the non regression test, which is basically what you tested online, against the compiled version.
Probably you should have a little look at the source code and doc as well.
I've set this back to 'Needs Review' because clearly needs it.
Hmmm.
If you do a review, which I think you have done, then you have done it:-)
If you consider that your test was not a review and you do not intend to provide one, then thanks for the feedback anyway, and maybe you should consider removing yourself from the "Reviewer" column, otherwise nobody will provide a review.