Interesting find!

We are using a MenuTagMultiselectWidget here, but somehow its "disabled" view in AbuseFilter differs from what you see in OOUI demos. If I were to guess, I would say we are not using the right method/property to mark it as disabled.

Yep, I think so. Maybe there've been an update to the widget. Will check in a few days.

I see that AF is passing the correct value for disabled, that the above part of the widget is indeed greyed out, and the docs say that disabled is still an option for TagMultiselectWidget. But still, the input widget is writeable. Probably some bug/regression in OOUI itself.

I'd leave it untriaged for OOUI people. This is not only impacting AF, but the entire OOUI library, which has a wider use. Sure, it's only a minor, visual glitch, but I can't if low is fine, without knowing what exactly is affected by this bug.

I checked this again, and AFICS there are two factors contributing to this bug.

First, the logic for setting the input disabled (here) is:

this.input.setDisabled( !!isDisabled && !this.isUnderLimit() );

At first glance it seems that the logic operator is wrong, it should be a logic OR, not AND. Right now, the "disabled" status of the main widget is ignored when we're under the limit, which for the AF use case is always true.

Second, even after the fix above, the AF code would not work because it sets the "disabled" property when constructing the widget:

selector = new OO.ui.TagMultiselectWidget( {
	// ...
	disabled: config.disabled
} );

but it would work if I change it to

selector = new OO.ui.TagMultiselectWidget( {
	// ...
} );
selector.setDisabled( config.disabled );

In turn, this happens because the TagMultiselectWidget constructor has:

this.input.setDisabled( this.isDisabled() ); // <-- this line correctly disables the input
// ...
if ( config.selected ) {
	this.setValue( config.selected );
}

And the setValue call is causing the "disabled" status to go away. I haven't investigated any further, though.

Change 668493 had a related patch set uploaded (by Esanders; owner: Esanders):
[oojs/ui@master] TagMultiselectWidget: Fix typo in disable logic

https://gerrit.wikimedia.org/r/668493

Change 668493 merged by jenkins-bot:
[oojs/ui@master] TagMultiselectWidget: Fix typo in disable logic

https://gerrit.wikimedia.org/r/668493

Change 671278 had a related patch set uploaded (by Jforrester; owner: Jforrester):
[mediawiki/core@master] Update OOUI to v0.41.3

https://gerrit.wikimedia.org/r/671278

Change 671278 merged by jenkins-bot:
[mediawiki/core@master] Update OOUI to v0.41.3

https://gerrit.wikimedia.org/r/671278