Eli Zaretskii <eliz@gnu.org> writes:

>> I do not mind adding tests, but it will not be as fast - I need help
>> with them.
>
> We could install just a few now, and the rest afterwards.  You have
> already presented enough non-trivial cases that can be easily
> converted to tests, and I think it is a good idea to do that when we
> change such low-level and veteran code.

See the attached.
I am not sure if these few cases are enough to warrant a separate commit
though.