[autotests/integration] Add a test case for closing DebugConsole

This test simulates closing the DebugConsole through the window
decoration. Which unlike the dedicated button does not destroy the
DebugConsole.

CCBUG: 369858

autotests/integration/debug_console_test.cpp

@@ -52,6 +52,7 @@ private Q_SLOTS:
     void testWaylandClient_data();
     void testWaylandClient();
     void testInternalWindow();
+    void testClosingDebugConsole();
 };
 
 void DebugConsoleTest::initTestCase()
@@ -502,6 +503,30 @@ void DebugConsoleTest::testInternalWindow()
     QCOMPARE(rowsRemovedSpy.first().first().value<QModelIndex>(), internalTopLevelIndex);
 }
 
+void DebugConsoleTest::testClosingDebugConsole()
+{
+    // this test verifies that the DebugConsole gets destroyed when closing the window
+    // BUG: 369858
+
+    DebugConsole *console = new DebugConsole;
+    QSignalSpy destroyedSpy(console, &QObject::destroyed);
+    QVERIFY(destroyedSpy.isValid());
+
+    QSignalSpy clientAddedSpy(waylandServer(), &WaylandServer::shellClientAdded);
+    QVERIFY(clientAddedSpy.isValid());
+    console->show();
+    QCOMPARE(console->windowHandle()->isVisible(), true);
+    QTRY_COMPARE(clientAddedSpy.count(), 1);
+    ShellClient *c = clientAddedSpy.first().first().value<ShellClient*>();
+    QVERIFY(c->isInternal());
+    QCOMPARE(c->internalWindow(), console->windowHandle());
+    QVERIFY(c->isDecorated());
+    c->closeWindow();
+    QEXPECT_FAIL("", "BUG 369858", Continue);
+    QVERIFY(destroyedSpy.wait());
+    QCOMPARE(console->windowHandle()->isVisible(), false);
+}
+
 }
 
 WAYLANDTEST_MAIN(KWin::DebugConsoleTest)

debug_console.h

@@ -94,7 +94,7 @@ public:
     QString displayText(const QVariant &value, const QLocale &locale) const override;
 };
 
-class DebugConsole : public QWidget
+class KWIN_EXPORT DebugConsole : public QWidget
 {
     Q_OBJECT
 public: