Fix crash in incubator when a guarded context is deleted

Change-Id: Ice7375c344b7e8d0d11cc6ee0bdfdf864ecd7109
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>

4 files changed, 27 insertions, 1 deletions

diff --git a/src/declarative/qml/qdeclarativeincubator.cpp b/src/declarative/qml/qdeclarativeincubator.cpp
index 80bdfac24a..bedf355854 100644
--- a/src/declarative/qml/qdeclarativeincubator.cpp
+++ b/src/declarative/qml/qdeclarativeincubator.cpp
@@ -97,6 +97,7 @@ void QDeclarativeEnginePrivate::incubate(QDeclarativeIncubator &i, QDeclarativeC
         incubatorList.insert(p);
         incubatorCount++;
 
+        p->vmeGuard.guard(&p->vme);
         p->changeStatus(QDeclarativeIncubator::Loading);
 
         if (incubationController)
diff --git a/src/declarative/qml/qdeclarativevme.cpp b/src/declarative/qml/qdeclarativevme.cpp
index e39a7c90f8..8f11b2842d 100644
--- a/src/declarative/qml/qdeclarativevme.cpp
+++ b/src/declarative/qml/qdeclarativevme.cpp
@@ -1455,7 +1455,7 @@ void QDeclarativeVMEGuard::guard(QDeclarativeVME *vme)
     for (int ii = 0; ii < m_objectCount; ++ii)
         m_objects[ii] = vme->objects[ii];
 
-    m_contextCount = (vme->rootContext.isNull())?0:1 + vme->states.count();
+    m_contextCount = (vme->rootContext.isNull()?0:1) + vme->states.count();
     m_contexts = new QDeclarativeGuardedContextData[m_contextCount];
     for (int ii = 0; ii < vme->states.count(); ++ii) 
         m_contexts[ii] = vme->states.at(ii).context;
diff --git a/tests/auto/declarative/qdeclarativeincubator/data/contextDelete.qml b/tests/auto/declarative/qdeclarativeincubator/data/contextDelete.qml
new file mode 100644
index 0000000000..c3952074f1
--- /dev/null
+++ b/tests/auto/declarative/qdeclarativeincubator/data/contextDelete.qml
@@ -0,0 +1,5 @@
+import QtQuick 2.0
+
+QtObject {
+    property int dummy: 12
+}
diff --git a/tests/auto/declarative/qdeclarativeincubator/tst_qdeclarativeincubator.cpp b/tests/auto/declarative/qdeclarativeincubator/tst_qdeclarativeincubator.cpp
index 54ca622753..efa46264c3 100644
--- a/tests/auto/declarative/qdeclarativeincubator/tst_qdeclarativeincubator.cpp
+++ b/tests/auto/declarative/qdeclarativeincubator/tst_qdeclarativeincubator.cpp
@@ -47,6 +47,7 @@
 #include <QPointer>
 #include <QFileInfo>
 #include <QDeclarativeEngine>
+#include <QDeclarativeContext>
 #include <QDeclarativeProperty>
 #include <QDeclarativeComponent>
 #include <QDeclarativeIncubator>
@@ -85,6 +86,7 @@ private slots:
     void chainedAsynchronousIfNested();
     void chainedAsynchronousIfNestedOnCompleted();
     void selfDelete();
+    void contextDelete();
 
 private:
     QDeclarativeIncubationController controller;
@@ -975,6 +977,24 @@ void tst_qdeclarativeincubator::selfDelete()
     }
 }
 
+// Test that QML doesn't crash if the context is deleted prior to the incubator
+// first executing.
+void tst_qdeclarativeincubator::contextDelete()
+{
+    QDeclarativeContext *context = new QDeclarativeContext(engine.rootContext());
+    QDeclarativeComponent component(&engine, TEST_FILE("contextDelete.qml"));
+
+    QDeclarativeIncubator incubator;
+    component.create(incubator, context);
+
+    delete context;
+
+    {
+        bool b = false;
+        controller.incubateWhile(&b);
+    }
+}
+
 QTEST_MAIN(tst_qdeclarativeincubator)
 
 #include "tst_qdeclarativeincubator.moc"