QNetworkReplyImpl: Protect against recursive event loops

This fixes a bug that occured together with a QProgressDialog.
The signal emission was like:
readyRead readyRead readyRead [...] readyRead finished readyRead
Now finished should be properly at the ending of this sequence.

Task-number: 256630
Reviewed-by: Thiago Macieira <thiago.macieira@nokia.com>

2 files changed, 39 insertions, 2 deletions

diff --git a/src/network/access/qnetworkreplyimpl.cpp b/src/network/access/qnetworkreplyimpl.cpp
index e8cb6ee..d903d03 100644
--- a/src/network/access/qnetworkreplyimpl.cpp
+++ b/src/network/access/qnetworkreplyimpl.cpp
@@ -54,6 +54,7 @@ QT_BEGIN_NAMESPACE
 inline QNetworkReplyImplPrivate::QNetworkReplyImplPrivate()
     : copyDevice(0), networkCache(0),
       cacheEnabled(false), cacheSaveDevice(0),
+      notificationHandlingPaused(false),
       bytesDownloaded(0), lastBytesDownloaded(-1), bytesUploaded(-1),
       state(Idle)
 {
@@ -164,9 +165,11 @@ void QNetworkReplyImplPrivate::_q_copyReadyRead()
 
     lastBytesDownloaded = bytesDownloaded;
     QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
+    pauseNotificationHandling();
     emit q->downloadProgress(bytesDownloaded,
                              totalSize.isNull() ? Q_INT64_C(-1) : totalSize.toLongLong());
     emit q->readyRead();
+    resumeNotificationHandling();
 }
 
 void QNetworkReplyImplPrivate::_q_copyReadChannelFinished()
@@ -210,6 +213,9 @@ void QNetworkReplyImplPrivate::backendNotify(InternalNotifications notification)
 
 void QNetworkReplyImplPrivate::handleNotifications()
 {
+    if (notificationHandlingPaused)
+        return;
+
     NotificationQueue current = pendingNotifications;
     pendingNotifications.clear();
 
@@ -248,6 +254,22 @@ void QNetworkReplyImplPrivate::handleNotifications()
     }
 }
 
+// Do not handle the notifications while we are emitting downloadProgress
+// or readyRead
+void QNetworkReplyImplPrivate::pauseNotificationHandling()
+{
+    notificationHandlingPaused = true;
+}
+
+// Resume notification handling
+void QNetworkReplyImplPrivate::resumeNotificationHandling()
+{
+    Q_Q(QNetworkReplyImpl);
+    notificationHandlingPaused = false;
+    if (pendingNotifications.size() >= 1)
+        QCoreApplication::postEvent(q, new QEvent(QEvent::NetworkReplyUpdated));
+}
+
 void QNetworkReplyImplPrivate::createCache()
 {
     // check if we can save and if we're allowed to
@@ -318,8 +340,10 @@ void QNetworkReplyImplPrivate::consume(qint64 count)
         bytesUploaded += count;
 
     QVariant totalSize = request.header(QNetworkRequest::ContentLengthHeader);
+    pauseNotificationHandling();
     emit q->uploadProgress(bytesUploaded,
                            totalSize.isNull() ? Q_INT64_C(-1) : totalSize.toLongLong());
+    resumeNotificationHandling();
 }
 
 qint64 QNetworkReplyImplPrivate::nextDownstreamBlockSize() const
@@ -367,12 +391,14 @@ void QNetworkReplyImplPrivate::feed(const QByteArray &data)
     QPointer<QNetworkReplyImpl> qq = q;
 
     QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
+    pauseNotificationHandling();
     emit q->downloadProgress(bytesDownloaded,
                              totalSize.isNull() ? Q_INT64_C(-1) : totalSize.toLongLong());
     emit q->readyRead();
 
     // hopefully we haven't been deleted here
     if (!qq.isNull()) {
+        resumeNotificationHandling();
         // do we still have room in the buffer?
         if (nextDownstreamBlockSize() > 0)
             backendNotify(QNetworkReplyImplPrivate::NotifyDownstreamReadyWrite);
@@ -409,19 +435,25 @@ void QNetworkReplyImplPrivate::finished()
     state = Finished;
     pendingNotifications.clear();
 
+    pauseNotificationHandling();
     QVariant totalSize = cookedHeaders.value(QNetworkRequest::ContentLengthHeader);
-    if (bytesDownloaded != lastBytesDownloaded || totalSize.isNull())
+    if (bytesDownloaded != lastBytesDownloaded || totalSize.isNull()) {
         emit q->downloadProgress(bytesDownloaded, bytesDownloaded);
-    if (bytesUploaded == -1 && outgoingData)
+    }
+    if (bytesUploaded == -1 && outgoingData) {
         emit q->uploadProgress(0, 0);
+    }
+    resumeNotificationHandling();
 
     completeCacheSave();
 
     // note: might not be a good idea, since users could decide to delete us
     // which would delete the backend too...
     // maybe we should protect the backend
+    pauseNotificationHandling();
     emit q->readChannelFinished();
     emit q->finished();
+    resumeNotificationHandling();
 }
 
 void QNetworkReplyImplPrivate::error(QNetworkReplyImpl::NetworkError code, const QString &errorMessage)
diff --git a/src/network/access/qnetworkreplyimpl_p.h b/src/network/access/qnetworkreplyimpl_p.h
index 32bfa4c..65b3679 100644
--- a/src/network/access/qnetworkreplyimpl_p.h
+++ b/src/network/access/qnetworkreplyimpl_p.h
@@ -129,6 +129,9 @@ public:
     void setup(QNetworkAccessManager::Operation op, const QNetworkRequest &request,
                QIODevice *outgoingData);
     void setNetworkCache(QAbstractNetworkCache *networkCache);
+
+    void pauseNotificationHandling();
+    void resumeNotificationHandling();
     void backendNotify(InternalNotifications notification);
     void handleNotifications();
     void createCache();
@@ -156,6 +159,8 @@ public:
     QIODevice *cacheSaveDevice;
 
     NotificationQueue pendingNotifications;
+    bool notificationHandlingPaused;
+
     QUrl urlForLastAuthentication;
 #ifndef QT_NO_NETWORKPROXY
     QNetworkProxy lastProxyAuthentication;