Fix crash when connecting a new screen

In QWaylandWindow::virtualSiblings, don't include screens that have not been
added yet. I.e. QWaylandScreens for which QPlatformIntegration::screenAdded has
not yet been called.

There are two reasons why this crash wasn't covered by the
removePrimaryScreen() test. First of all, the mock output didn't send
wl_output.done events when updating the mode/geometry. These wayland events are
what causes QWindowSystemInterface::handleScreenGeometryChange() to be called
(where virtualSiblings are called).

Furthermore, virtualSiblings is only called when the geometry actually changes,
so add a new test that changes the screen geometry of the existing screen while
a new one is being added (i.e. moves it to the right).

Task-number: QTBUG-62044
Change-Id: I623fbf8799d21c6b9293e7120ded301277639cc6
Reviewed-by: David Edmundson <davidedmundson@kde.org>
Reviewed-by: Aleix Pol
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/auto/client/client/tst_client.cpp b/tests/auto/client/client/tst_client.cpp
index 981b8f129..e244de7f2 100644
--- a/tests/auto/client/client/tst_client.cpp
+++ b/tests/auto/client/client/tst_client.cpp
@@ -164,6 +164,7 @@ public slots:
 private slots:
     void primaryScreen();
     void screens();
+    void addScreenWithGeometryChange();
     void windowScreens();
     void removePrimaryScreen();
     void createDestroyWindow();
@@ -197,6 +198,29 @@ void tst_WaylandClient::screens()
     QTRY_COMPARE(QGuiApplication::screens().size(), 1);
 }
 
+//QTBUG-62044
+void tst_WaylandClient::addScreenWithGeometryChange()
+{
+    QTRY_COMPARE(QGuiApplication::screens().size(), 1);
+    const QRect oldGeometry = QGuiApplication::primaryScreen()->geometry();
+    compositor->sendAddOutput();
+
+    // Move the primary screen to the right
+    const QRect newGeometry(QPoint(screenSize.width(), 0), screenSize);
+    Q_ASSERT(oldGeometry != newGeometry);
+    compositor->sendOutputGeometry(compositor->output(0), newGeometry);
+
+    QTRY_COMPARE(QGuiApplication::screens().size(), 2);
+    QTRY_COMPARE(QGuiApplication::primaryScreen()->geometry(), newGeometry);
+
+    compositor->sendRemoveOutput(compositor->output(1));
+    QTRY_COMPARE(QGuiApplication::screens().size(), 1);
+
+    // Move the screen back
+    compositor->sendOutputGeometry(compositor->output(0), oldGeometry);
+    QTRY_COMPARE(QGuiApplication::primaryScreen()->geometry(), oldGeometry);
+}
+
 void tst_WaylandClient::windowScreens()
 {
     QSharedPointer<MockOutput> firstOutput;
@@ -255,6 +279,7 @@ void tst_WaylandClient::removePrimaryScreen()
     compositor->sendAddOutput();
 
     QTRY_COMPARE(QGuiApplication::screens().size(), 2);
+    QTRY_COMPARE(QGuiApplication::primaryScreen()->virtualSiblings().size(), 2);
     QScreen *secondaryScreen = QGuiApplication::screens().at(1);
     QVERIFY(secondaryScreen);