Fix crash on WebContentsDelegateQt::CloseContents()

CloseContents() triggers a windowCloseRequested() signal. The handler of
the signal might close the QWebEngineView and it would result the
destruction of the WebContentsDelegateQt. Thus, any operation on
WebContentsDelegateQt is not safe after a
WebContentsAdapterClient::close() call.

For example, calling QWebEngineView::close() on
QWebEnginePage::windowCloseRequested() would result crash because it
sets life cycle state to discarded which destructs web contents.

Fixes: QTBUG-84355
Change-Id: I5da404bc9b1923cc19085ee899b550da49d1416b
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

1 files changed, 22 insertions, 0 deletions

diff --git a/tests/auto/widgets/qwebenginepage/tst_qwebenginepage.cpp b/tests/auto/widgets/qwebenginepage/tst_qwebenginepage.cpp
index 515aa4ebb..e4e451a55 100644
--- a/tests/auto/widgets/qwebenginepage/tst_qwebenginepage.cpp
+++ b/tests/auto/widgets/qwebenginepage/tst_qwebenginepage.cpp
@@ -231,6 +231,7 @@ private Q_SLOTS:
     void renderProcessPid();
     void backgroundColor();
     void audioMuted();
+    void closeContents();
 
 private:
     static QPoint elementCenter(QWebEnginePage *page, const QString &id);
@@ -4641,6 +4642,27 @@ void tst_QWebEnginePage::audioMuted()
     QCOMPARE(spy[1][0], QVariant(false));
 }
 
+void tst_QWebEnginePage::closeContents()
+{
+    TestPage page;
+    QSignalSpy windowCreatedSpy(&page, &TestPage::windowCreated);
+    page.runJavaScript("var dialog = window.open('', '', 'width=100, height=100');");
+    QTRY_COMPARE(windowCreatedSpy.count(), 1);
+
+    QWebEngineView *dialogView = new QWebEngineView;
+    QWebEnginePage *dialogPage = page.createdWindows[0];
+    dialogPage->setView(dialogView);
+    QCOMPARE(dialogPage->lifecycleState(), QWebEnginePage::LifecycleState::Active);
+
+    // This should not crash.
+    connect(dialogPage, &QWebEnginePage::windowCloseRequested, dialogView, &QWebEngineView::close);
+    page.runJavaScript("dialog.close();");
+
+    // QWebEngineView::closeEvent() sets the life cycle state to discarded.
+    QTRY_COMPARE(dialogPage->lifecycleState(), QWebEnginePage::LifecycleState::Discarded);
+    delete dialogView;
+}
+
 static QByteArrayList params = {QByteArrayLiteral("--use-fake-device-for-media-stream")};
 W_QTEST_MAIN(tst_QWebEnginePage, params)