Modal dialog removes all document focusin handlers in _destroyOverlay

[RandScullard]

The dialog widget uses this._on to add a focusin event handler at the document level in the _createOverlay function:

this._on( this.document, {
	focusin: function( event ) {
		if ( isOpening ) {
			return;
		}

		if ( !this._allowInteraction( event ) ) {
			event.preventDefault();
			this._trackingInstances()[ 0 ]._focusTabbable();
		}
	}
});

However, it then uses unbind to remove the handler in the _destroyOverlay function:

this.document
	.unbind( "focusin" )
	.removeData( "ui-dialog-overlays" );

As a result, it removes all focusin handlers at the document level, rather than just its own. It seems that it should use this._off instead:

this._off( this.document, "focusin" );
this.document
	.removeData( "ui-dialog-overlays" );

Here is a reduced test case that demonstrates the problem: ​https://jsfiddle.net/eu4ua6kj/2/

[Scott González]

Dialog: Fix removal of event listener for modal dialogs

Fixes #13649

Changeset: 62446d957efb69cd53015919edf71501fcbd2599