Super shortcuts breaks application keyboard input

[Michael Sheldon]

Pressing Super+A results in focus being taken from applications without the release key event being sent for the Super key. This means that when focus is restored to an application it believes that the Super key is permanently being held down unless the user presses it again.

The effects of this can be seen in most applications that accept keyboard input, for example in the terminal cursor input stops working instead just inserting A/B/C/D characters, in the webbrowser keyboard shortcuts no longer work, in Kate cursor movement stops working, etc.

Steps to reproduce:

1. Run the following QML:

import QtQuick 2.4
import Ubuntu.Components 1.3

MainView {

    property bool superPress: false
    focus: true

    Label {
        anchors.centerIn: parent
        text: "Super pressed? " + (superPress ? "True" : "False")
    }

    Keys.onPressed: {
        if (event.key == Qt.Key_Super_L) {
            superPress = true
        }
    }

    Keys.onReleased: {
        if (event.key == Qt.Key_Super_L) {
            superPress = false
        }
    }

}

2. Hold Super+A until the app drawer opens

3. Click on the QML application to restore its focus

Expected result:

QML application should be showing: "Super pressed? False"

Actual result:

QML application shows: "Super pressed? True" because the release event was never sent to the application when the application drawer took focus.

[Michael Sheldon (michael-sheldon)]

The same issue can be triggered if you hold the super key to reveal the launcher and then click on an application icon, or if you use any of the super+1/2/3/etc. short cuts to launch an application.

[Daniel van Vugt (vanvugt)]

Could be related to Mir bug 1536279, which has not been Fix Released yet.