1 files changed, 21 insertions, 0 deletions
diff --git a/src/declarative/qml/qdeclarativecontext.cpp b/src/declarative/qml/qdeclarativecontext.cpp
index 9307bcc..ba4da95 100644
--- a/src/declarative/qml/qdeclarativecontext.cpp
+++ b/src/declarative/qml/qdeclarativecontext.cpp
@@ -202,6 +202,12 @@ QDeclarativeContext::~QDeclarativeContext()
         d->data->destroy();
 }
 
+bool QDeclarativeContext::isValid() const
+{
+    Q_D(const QDeclarativeContext);
+    return d->data && d->data->isValid();
+}
+
 /*!
     Return the context's QDeclarativeEngine, or 0 if the context has no QDeclarativeEngine or the
     QDeclarativeEngine was destroyed.
@@ -245,6 +251,11 @@ void QDeclarativeContext::setContextObject(QObject *object)
         return;
     }
 
+    if (!isValid()) {
+        qWarning("QDeclarativeContext: Cannot set context object on invalid context.");
+        return;
+    }
+
     data->contextObject = object;
 }
 
@@ -264,6 +275,11 @@ void QDeclarativeContext::setContextProperty(const QString &name, const QVariant
         return;
     }
 
+    if (!isValid()) {
+        qWarning("QDeclarativeContext: Cannot set property on invalid context.");
+        return;
+    }
+
     if (data->engine) {
         bool ok;
         QObject *o = QDeclarativeEnginePrivate::get(data->engine)->toQObject(value, &ok);
@@ -305,6 +321,11 @@ void QDeclarativeContext::setContextProperty(const QString &name, QObject *value
         return;
     }
 
+    if (!isValid()) {
+        qWarning("QDeclarativeContext: Cannot set property on invalid context.");
+        return;
+    }
+
     if (!data->propertyNames) data->propertyNames = new QDeclarativeIntegerCache(data->engine);
     int idx = data->propertyNames->value(name);