From 3308f359848fc193b3c9d222179bc58136bea834 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Fri, 15 Jul 2016 16:06:09 +0200
Subject: [PATCH] Handle restart of Compositor Scene correctly for Wayland
 client

Summary:
This change ensures that KWin doesn't crash in the QPainter scene if
the compositor gets restarted and if there are Wayland clients.

BUG: 365471

Test Plan:
Test case added to scene qpainter which triggers a restart
of the Compositor with a window being shown. Verifies that rendering
is correct afterwards.

Reviewers: #kwin, #plasma_on_wayland

Subscribers: plasma-devel, kwin

Tags: #plasma_on_wayland, #kwin

Differential Revision: https://phabricator.kde.org/D2185
---
 autotests/integration/scene_qpainter_test.cpp | 53 +++++++++++++++++++
 composite.cpp                                 |  7 +++
 2 files changed, 60 insertions(+)

diff --git a/autotests/integration/scene_qpainter_test.cpp b/autotests/integration/scene_qpainter_test.cpp
index ee6cbae5f3..73158b3f2c 100644
--- a/autotests/integration/scene_qpainter_test.cpp
+++ b/autotests/integration/scene_qpainter_test.cpp
@@ -49,6 +49,8 @@ private Q_SLOTS:
     void testCursorMoving();
     void testWindow_data();
     void testWindow();
+    void testCompositorRestart_data();
+    void testCompositorRestart();
 };
 
 void SceneQPainterTest::cleanup()
@@ -188,5 +190,56 @@ void SceneQPainterTest::testWindow()
     QCOMPARE(referenceImage, *scene->backend()->buffer());
 }
 
+void SceneQPainterTest::testCompositorRestart_data()
+{
+    QTest::addColumn<Test::ShellSurfaceType>("type");
+
+    QTest::newRow("wlShell") << Test::ShellSurfaceType::WlShell;
+    QTest::newRow("xdgShellV5") << Test::ShellSurfaceType::XdgShellV5;
+}
+
+void SceneQPainterTest::testCompositorRestart()
+{
+    // this test verifies that the compositor/SceneQPainter survive a restart of the compositor and still render correctly
+    KWin::Cursor::setPos(400, 400);
+
+    // first create a window
+    using namespace KWayland::Client;
+    QVERIFY(Test::setupWaylandConnection(s_socketName));
+    QScopedPointer<Surface> s(Test::createSurface());
+    QFETCH(Test::ShellSurfaceType, type);
+    QScopedPointer<QObject> ss(Test::createShellSurface(type, s.data()));
+    QVERIFY(Test::renderAndWaitForShown(s.data(), QSize(200, 300), Qt::blue));
+
+    // now let's try to reinitialize the compositing scene
+    auto oldScene = KWin::Compositor::self()->scene();
+    QVERIFY(oldScene);
+    QSignalSpy sceneCreatedSpy(KWin::Compositor::self(), &KWin::Compositor::sceneCreated);
+    QVERIFY(sceneCreatedSpy.isValid());
+    KWin::Compositor::self()->slotReinitialize();
+    if (sceneCreatedSpy.isEmpty()) {
+        QVERIFY(sceneCreatedSpy.wait());
+    }
+    QCOMPARE(sceneCreatedSpy.count(), 1);
+    auto scene = qobject_cast<SceneQPainter*>(KWin::Compositor::self()->scene());
+    QVERIFY(scene);
+
+    // this should directly trigger a frame
+    KWin::Compositor::self()->addRepaintFull();
+    QSignalSpy frameRenderedSpy(scene, &Scene::frameRendered);
+    QVERIFY(frameRenderedSpy.isValid());
+    QVERIFY(frameRenderedSpy.wait());
+
+    // render reference image
+    QImage referenceImage(QSize(1280, 1024), QImage::Format_RGB32);
+    referenceImage.fill(Qt::black);
+    QPainter painter(&referenceImage);
+    painter.fillRect(0, 0, 200, 300, Qt::blue);
+    const QImage cursorImage = kwinApp()->platform()->softwareCursor();
+    QVERIFY(!cursorImage.isNull());
+    painter.drawImage(QPoint(400, 400) - kwinApp()->platform()->softwareCursorHotspot(), cursorImage);
+    QCOMPARE(referenceImage, *scene->backend()->buffer());
+}
+
 WAYLANDTEST_MAIN(SceneQPainterTest)
 #include "scene_qpainter_test.moc"
diff --git a/composite.cpp b/composite.cpp
index cc43d0bbb4..62775f67cc 100644
--- a/composite.cpp
+++ b/composite.cpp
@@ -324,6 +324,13 @@ void Compositor::startupWithWorkspace()
         c->setupCompositing();
         c->getShadow();
     }
+    if (auto w = waylandServer()) {
+        const auto clients = w->clients();
+        for (auto c : clients) {
+            c->setupCompositing();
+            c->getShadow();
+        }
+    }
 
     emit compositingToggled(true);