maxlength attribute not working on new input[type=number]

[tbuteler]

I don't know if this categorizes as a WP bug or just browser bugs, but the maxlength attributes on the "div.screen-options input.screen-per-page" elements is not working after the upgrade to 3.4 changed their type from "text" to "number".

As tested on the latest versions of Chrome, Safari and Opera (which render a spin box on the left of the element), you can have any number you want inside the box. Firefox, which relies solely on keyboard input, is the only one that honors the maxlength of 3.

If this change was decided so that iOS users can have a numeric keyboard, this seems to provide an alternative: ​http://stackoverflow.com/a/4882479/754914

Related: #17863

Would max="999" on the input not work? (if we're capping it at a length of 3)

We only use maxlength in a few places. This is the only instance of maxlength + type="number". Forcing it to 999 works, as that's what we sanitize on the PHP side.

In [20625]:

Add a max of 999 to the screen options items per page input. props georgestephanis. fixes #20420.