QQmlEngineDebugService: Check QML contexts for validity

We should not operate on invalid QML contexts and once we have
established a context to be valid we don't have to check the result of
QQmlContextData::get anymore.

Change-Id: I9106115ddf925c3572048f1fd334bdfd9a9cfca7
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp b/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp
index d9a4777115..57e95f7b89 100644
--- a/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp
+++ b/tests/auto/qml/debugger/qqmlenginedebugservice/tst_qqmlenginedebugservice.cpp
@@ -99,6 +99,8 @@ private:
                              const QmlDebugObjectReference &oref,
                              bool recursive) const;
 
+    void getContexts();
+
     QQmlDebugConnection *m_conn;
     QQmlEngineDebugClient *m_dbg;
     QQmlEngine *m_engine;
@@ -138,6 +140,7 @@ private slots:
     void regression_QTCREATORBUG_7451();
     void queryObjectWithNonStreamableTypes();
     void asynchronousCreate();
+    void invalidContexts();
 };
 
 QmlDebugObjectReference tst_QQmlEngineDebugService::findRootObject(
@@ -248,6 +251,22 @@ void tst_QQmlEngineDebugService::recursiveObjectTest(
     }
 }
 
+void tst_QQmlEngineDebugService::getContexts()
+{
+    bool success = false;
+
+    m_dbg->queryAvailableEngines(&success);
+    QVERIFY(success);
+    QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
+
+    QList<QmlDebugEngineReference> engines = m_dbg->engines();
+    QCOMPARE(engines.count(), 1);
+    m_dbg->queryRootContexts(engines.first().debugId, &success);
+
+    QVERIFY(success);
+    QVERIFY(QQmlDebugTest::waitForSignal(m_dbg, SIGNAL(result())));
+}
+
 void tst_QQmlEngineDebugService::initTestCase()
 {
     qmlRegisterType<NonScriptProperty>("Test", 1, 0, "NonScriptPropertyElement");
@@ -1289,6 +1308,26 @@ void tst_QQmlEngineDebugService::asynchronousCreate() {
     QTRY_COMPARE(m_dbg->object().idString, QLatin1String("asyncRect"));
 }
 
+void tst_QQmlEngineDebugService::invalidContexts()
+{
+    getContexts();
+    const int base = m_dbg->rootContext().contexts.count();
+    QQmlContext context(m_engine);
+    getContexts();
+    QCOMPARE(m_dbg->rootContext().contexts.count(), base + 1);
+    QQmlContextData *contextData = QQmlContextData::get(&context);
+    contextData->invalidate();
+    getContexts();
+    QCOMPARE(m_dbg->rootContext().contexts.count(), base);
+    QQmlContextData *rootData = QQmlContextData::get(m_engine->rootContext());
+    rootData->invalidate();
+    getContexts();
+    QCOMPARE(m_dbg->rootContext().contexts.count(), 0);
+    contextData->setParent(rootData); // makes context valid again, but not root.
+    getContexts();
+    QCOMPARE(m_dbg->rootContext().contexts.count(), 0);
+}
+
 int main(int argc, char *argv[])
 {
     int _argc = argc + 1;