Dialog moveToTop

The function moveToTop hasn't functioned correctly for years - I've found bugs and assistance requests going back to 2013 and earlier. Most are hacks to get around the functionality not brining the dialog to the top, even when requesting the moveToTop function directly it is still in-behind other items.

It is possible for any DOM element to have a higher z-index than the initial .ui-front element created by jquery-ui and can mean a dialog can hide behind elements that are already presented on the page.

I suggest the following change to the _moveToTop function which maps all DOM elements and not only ones matching .ui-front.

/ui/widgets/dialog.js

_moveToTop: function (event, silent) {
	var moved = false,
		zIndices = $( "*:visible" ).map( function() {
			return +(isNaN(z = $( this ).css( "z-index" )) ? 0 : z);
		} ).get(),
		zIndexMax = Math.max.apply( null, zIndices );

	if ( zIndexMax >= +this.uiDialog.css( "z-index" ) ) {
		this.uiDialog.css( "z-index", zIndexMax + 1 );
		moved = true;
	}

	if ( moved && !silent ) {
		this._trigger( "focus", event );
	}

	return moved;
},

Start in ui/widgets/dialog.js at _moveToTop and review how the dialog currently determines its z-index. Compare that behavior with the issue's proposed handling of visible DOM elements. Done means moveToTop keeps the dialog above other visible elements and preserves the existing focus behavior when it moves.