Simplify negated search operations

[cedric-anne]

Checklist before requesting a review

• I have read the CONTRIBUTING document.
• I have performed a self-review of my code.

Description

It may fix #18251, but it may also completely break existing tests.

[trasher]

As discussed on our internal channel, this is the kind of issue that has existed for years... This would need to add many, many tests (but I do not have any idea which ones).

We also know the whole search mechanisms should be rewritten... There probably are issues that cannot be solved until this is done.

I'm not sure I'll accept that kind of change on bugfixes version anyway.

[cedric-anne]

As discussed on our internal channel, this is the kind of issue that has existed for years... This would need to add many, many tests (but I do not have any idea which ones).

We also know the whole search mechanisms should be rewritten... There probably are issues that cannot be solved until this is done.

I'm not sure I'll accept that kind of change on bugfixes version anyway.

I will keep this PR as a draft for now. It is not a priority, but I would like, at least, to add many tests, to prevent future regressions. We could then merge the tests in the bugfixes version, and the refacored code in the next major version.

[trasher]

Correct tests would fail on bugfixes version :D Anyway, that's not a priority, we'll see.