`add_option()` with `$autoload = false` adds option with autoload of "yes"

[dlh]

The docs for add_option() say that the autoload parameter accepts string|bool.

This is accurate in that using a boolean won't cause an error, but the function checks only 'no' === $autoload, such that if you call add_option() with $autoload = false, your option will be autoloaded.

The attached patch adds support for false and adds a unit test for autoload values after add_option().

Alternatively, the docs could be updated to just string.

[rmccue]

+1, I've hit this more than once.

[nacin]

One of the first things I ever worked on in WordPress core was #10788. This is where this originates, and yeah, I didn't do it right.

I'm going to re-jigger the unit test a bit to use a data provider (and avoid rand_str()). Please take a look as this is the preferred approach for writing tests of this nature, and that way the next time you submit a perfect bug report, and a perfect patch, it'll come with perfect tests, too. :)

[nacin]

In 31278:

Allow $autoload in add_option() to receive false.

props dllh.
fixes #31119.

[nacin]

Props dlh, not @dllh. Sorry. :-)