QNetworkAccessManager can delete the QAbstractNetworkCache pointer at

any point.  Rather then keep a separate pointer to the cache in the
reply use the pointer kept by the manager so the reply never tries
to access a cache pointer that has already been deleted.

Autotest: included
Merge-request: 1124
Reviewed-by: Thiago Macieira <thiago.macieira@nokia.com>

5 files changed, 40 insertions, 21 deletions

diff --git a/src/network/access/qnetworkaccessbackend.cpp b/src/network/access/qnetworkaccessbackend.cpp
index 615ce7cccd..947313c4ce 100644
--- a/src/network/access/qnetworkaccessbackend.cpp
+++ b/src/network/access/qnetworkaccessbackend.cpp
@@ -176,7 +176,9 @@ QList<QNetworkProxy> QNetworkAccessBackend::proxyList() const
 
 QAbstractNetworkCache *QNetworkAccessBackend::networkCache() const
 {
-    return reply->networkCache; // should be the same as manager->networkCache
+    if (!manager)
+        return 0;
+    return manager->networkCache;
 }
 
 void QNetworkAccessBackend::setCachingEnabled(bool enable)
diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index aafe44ba69..5a8756bcfb 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -692,9 +692,6 @@ QNetworkReply *QNetworkAccessManager::createRequest(QNetworkAccessManager::Opera
 
     // third step: setup the reply
     priv->setup(op, request, outgoingData);
-    if (request.attribute(QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferNetwork).toInt() !=
-        QNetworkRequest::AlwaysNetwork)
-        priv->setNetworkCache(d->networkCache);
 #ifndef QT_NO_NETWORKPROXY
     QList<QNetworkProxy> proxyList = d->queryProxy(QNetworkProxyQuery(request.url()));
     priv->proxyList = proxyList;
diff --git a/src/network/access/qnetworkreplyimpl.cpp b/src/network/access/qnetworkreplyimpl.cpp
index c37c66d48f..c805d59584 100644
--- a/src/network/access/qnetworkreplyimpl.cpp
+++ b/src/network/access/qnetworkreplyimpl.cpp
@@ -53,7 +53,7 @@ QT_BEGIN_NAMESPACE
 
 inline QNetworkReplyImplPrivate::QNetworkReplyImplPrivate()
     : backend(0), outgoingData(0),
-      copyDevice(0), networkCache(0),
+      copyDevice(0),
       cacheEnabled(false), cacheSaveDevice(0),
       notificationHandlingPaused(false),
       bytesDownloaded(0), lastBytesDownloaded(-1), bytesUploaded(-1),
@@ -203,11 +203,6 @@ void QNetworkReplyImplPrivate::setup(QNetworkAccessManager::Operation op, const
     QMetaObject::invokeMethod(q, "_q_startOperation", Qt::QueuedConnection);
 }
 
-void QNetworkReplyImplPrivate::setNetworkCache(QAbstractNetworkCache *nc)
-{
-    networkCache = nc;
-}
-
 void QNetworkReplyImplPrivate::backendNotify(InternalNotifications notification)
 {
     Q_Q(QNetworkReplyImpl);
@@ -277,17 +272,27 @@ void QNetworkReplyImplPrivate::resumeNotificationHandling()
         QCoreApplication::postEvent(q, new QEvent(QEvent::NetworkReplyUpdated));
 }
 
+QAbstractNetworkCache *QNetworkReplyImplPrivate::networkCache() const
+{
+    if (!backend)
+        return 0;
+    return backend->networkCache();
+}
+
 void QNetworkReplyImplPrivate::createCache()
 {
     // check if we can save and if we're allowed to
-    if (!networkCache || !request.attribute(QNetworkRequest::CacheSaveControlAttribute, true).toBool())
+    if (!networkCache()
+        || request.attribute(QNetworkRequest::CacheLoadControlAttribute,
+                             QNetworkRequest::PreferNetwork).toInt()
+            == QNetworkRequest::AlwaysNetwork)
         return;
     cacheEnabled = true;
 }
 
 bool QNetworkReplyImplPrivate::isCachingEnabled() const
 {
-    return (cacheEnabled && networkCache != 0);
+    return (cacheEnabled && networkCache() != 0);
 }
 
 void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
@@ -311,7 +316,7 @@ void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
         qDebug("QNetworkReplyImpl: setCachingEnabled(true) called after setCachingEnabled(false) -- "
                "backend %s probably needs to be fixed",
                backend->metaObject()->className());
-        networkCache->remove(url);
+        networkCache()->remove(url);
         cacheSaveDevice = 0;
         cacheEnabled = false;
     }
@@ -320,9 +325,9 @@ void QNetworkReplyImplPrivate::setCachingEnabled(bool enable)
 void QNetworkReplyImplPrivate::completeCacheSave()
 {
     if (cacheEnabled && errorCode != QNetworkReplyImpl::NoError) {
-        networkCache->remove(url);
+        networkCache()->remove(url);
     } else if (cacheEnabled && cacheSaveDevice) {
-        networkCache->insert(cacheSaveDevice);
+        networkCache()->insert(cacheSaveDevice);
     }
     cacheSaveDevice = 0;
     cacheEnabled = false;
@@ -385,15 +390,15 @@ void QNetworkReplyImplPrivate::feed(const QByteArray &data)
             metaData.setAttributes(attributes);
         }
 
-        cacheSaveDevice = networkCache->prepare(metaData);
+        cacheSaveDevice = networkCache()->prepare(metaData);
 
         if (!cacheSaveDevice || (cacheSaveDevice && !cacheSaveDevice->isOpen())) {
             if (cacheSaveDevice && !cacheSaveDevice->isOpen())
                 qCritical("QNetworkReplyImpl: network cache returned a device that is not open -- "
                       "class %s probably needs to be fixed",
-                      networkCache->metaObject()->className());
+                      networkCache()->metaObject()->className());
 
-            networkCache->remove(url);
+            networkCache()->remove(url);
             cacheSaveDevice = 0;
             cacheEnabled = false;
         }
@@ -524,7 +529,7 @@ QNetworkReplyImpl::~QNetworkReplyImpl()
 {
     Q_D(QNetworkReplyImpl);
     if (d->isCachingEnabled())
-        d->networkCache->remove(url());
+        d->networkCache()->remove(url());
 }
 
 void QNetworkReplyImpl::abort()
diff --git a/src/network/access/qnetworkreplyimpl_p.h b/src/network/access/qnetworkreplyimpl_p.h
index 0accaabbf7..f723b7f07c 100644
--- a/src/network/access/qnetworkreplyimpl_p.h
+++ b/src/network/access/qnetworkreplyimpl_p.h
@@ -128,7 +128,6 @@ public:
 
     void setup(QNetworkAccessManager::Operation op, const QNetworkRequest &request,
                QIODevice *outgoingData);
-    void setNetworkCache(QAbstractNetworkCache *networkCache);
 
     void pauseNotificationHandling();
     void resumeNotificationHandling();
@@ -153,7 +152,7 @@ public:
     QNetworkAccessBackend *backend;
     QIODevice *outgoingData;
     QIODevice *copyDevice;
-    QAbstractNetworkCache *networkCache;
+    QAbstractNetworkCache *networkCache() const;
 
     bool cacheEnabled;
     QIODevice *cacheSaveDevice;
diff --git a/tests/auto/qabstractnetworkcache/tst_qabstractnetworkcache.cpp b/tests/auto/qabstractnetworkcache/tst_qabstractnetworkcache.cpp
index e33807585f..ee49210a46 100644
--- a/tests/auto/qabstractnetworkcache/tst_qabstractnetworkcache.cpp
+++ b/tests/auto/qabstractnetworkcache/tst_qabstractnetworkcache.cpp
@@ -69,6 +69,8 @@ private slots:
     void cacheControl_data();
     void cacheControl();
 
+    void deleteCache();
+
 private:
     void check();
 };
@@ -269,6 +271,20 @@ void tst_QAbstractNetworkCache::check()
     QCOMPARE(diskCache->gotData, fetchFromCache);
 }
 
+void tst_QAbstractNetworkCache::deleteCache()
+{
+    QNetworkAccessManager manager;
+    NetworkDiskCache *diskCache = new NetworkDiskCache(&manager);
+    manager.setCache(diskCache);
+
+    QString url = "httpcachetest_cachecontrol.cgi?max-age=1000";
+    QNetworkRequest request(QUrl(TESTFILE + url));
+    QNetworkReply *reply = manager.get(request);
+    QSignalSpy downloaded1(reply, SIGNAL(finished()));
+    manager.setCache(0);
+    QTRY_COMPARE(downloaded1.count(), 1);
+}
+
 
 QTEST_MAIN(tst_QAbstractNetworkCache)
 #include "tst_qabstractnetworkcache.moc"