Comment 13 for bug 1501330

As Alex pointed out in comment #11, the issue is not webapp-container specific, it potentially affects all QML apps embedding a WebView and defining contextual actions. The branch I linked fixes the issue everywhere. This is an even more minimal standalone reproducer:

import QtQuick 2.4
import Ubuntu.Components 1.3
import Ubuntu.Web 0.2
WebView {
    url: "http://ubuntu.com"
    contextualActions: ActionList {
        Action {
            text: i18n.tr("Copy link")
            enabled: contextModel && contextModel.linkUrl.toString()
            onTriggered: Clipboard.push(["text/plain", contextModel.linkUrl.toString()])
        }
    }
}