Adding a filter to a callout breaks the clipping of content

[ConfidantCommunications]

I'm using a custom theme. If I apply a filter to a callout like below, the callout content (inside a Panel) will be shown outside the callout while scrolling. In the project.xml, allowhighdpi is set to true, antialiasing enabled, using openfl shared context.

var dropShadow = new DropShadowFilter(7,45,0,0.9,20,20,1,1,false,false,false);
callout.filters = [dropShadow];

[joshtynjala]

Here's more complete code required to reproduce this issue:

var button:Button;
button = new Button("Click Me", event -> {
	var panel = new Panel();
	panel.width = 70;
	var label = new Label("Hello");
	label.x = 50;
	panel.addChild(label);

	var callout = Callout.show(panel, button);
	var dropShadow = new DropShadowFilter(7, 45, 0, 0.9, 20, 20, 1, 1, false, false, false);
	callout.filters = [dropShadow];
});
addChild(button);

It renders correctly until you start scrolling. Interestingly, after scrolling a bit further, the masking seems to start working again temporarily.

Definitely an OpenFL bug.

The following seems to be a viable workaround until the bug in OpenFL can be fixed:

panel.scrollMode = SCROLL_RECT;