Ben Knoble [off-list ref] writes:

quoted

Changes since v2:

* Switch "! test_grep" to "test_grep !" in tests.

Thanks ! I did not read the tests carefully for semantic value,
but the rationale and overall code looks good to me as discussed
previously.

The range-diff here looks good, too. 

Thanks, both.  Let's mark it for 'next' then.