Doing a boolean && search ignores scoping

[Jane Sandberg]

I am seeing this issue in 3.1.1 and 3.1.2.

When I try a search limited to my library and involving multiple keywords, it works well:
* https://libcat.linnbenton.edu/eg/opac/results?query=dogs+cats&locg=7&detail_record_view=1 gives me books at my branch that include both the terms "dog" and "cat"

However, when I try to use the official boolean AND included in Evergreen (&&), it ignores the scoping, and gives me every result in every library that includes the terms "dog" and "cat":
* https://libcat.linnbenton.edu/eg/opac/results?query=dogs+%26%26+cats&locg=7&detail_record_view=1

This also goes for trying to use the boolean && for languages in multilingual search. The first of these queries is scoped properly, the second never is:

* item_lang(eng) item_lang(fre)
* item_lang(eng) && item_lang(fre)