Account for a reply that is finished before we can connect the signals

In a case where a connection is refused, then it is possible for it to
fail at the time that the QHttpNetworkReply is being created and
therefore after the connections have been made it would have already
emitted the signal to indicate it was finished with an error.

To account for this, then it checks if there is an error code set on
the reply and if there is then it will call the relevant slot right away.

Fixes: QTBUG-57799
Change-Id: I4e73e5c82092c09f825343d18db40b47c3cdb9ac
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

src/network/access/qhttpnetworkconnectionchannel.cpp

@@ -1099,6 +1099,7 @@ void QHttpNetworkConnectionChannel::_q_error(QAbstractSocket::SocketError socket
 
         if (reply) {
             reply->d_func()->errorString = errorString;
+            reply->d_func()->httpErrorCode = errorCode;
             emit reply->finishedWithError(errorCode, errorString);
             reply = 0;
             if (protocolHandler)

src/network/access/qhttpnetworkreply.cpp

@@ -158,6 +158,11 @@ QString QHttpNetworkReply::errorString() const
     return d_func()->errorString;
 }
 
+QNetworkReply::NetworkError QHttpNetworkReply::errorCode() const
+{
+    return d_func()->httpErrorCode;
+}
+
 QString QHttpNetworkReply::reasonPhrase() const
 {
     return d_func()->reasonPhrase;

src/network/access/qhttpnetworkreply_p.h

@@ -115,6 +115,8 @@ public:
     QString errorString() const;
     void setErrorString(const QString &error);
 
+    QNetworkReply::NetworkError errorCode() const;
+
     QString reasonPhrase() const;
 
     qint64 bytesAvailable() const;
@@ -259,6 +261,7 @@ public:
     qint64 removedContentLength;
     QPointer<QHttpNetworkConnection> connection;
     QPointer<QHttpNetworkConnectionChannel> connectionChannel;
+    QNetworkReply::NetworkError httpErrorCode = QNetworkReply::NoError;
 
     bool autoDecompress;
 

src/network/access/qhttpthreaddelegate.cpp

@@ -428,6 +428,12 @@ void QHttpThreadDelegate::startRequest()
 
     connect(httpReply, SIGNAL(cacheCredentials(QHttpNetworkRequest,QAuthenticator*)),
             this, SLOT(cacheCredentialsSlot(QHttpNetworkRequest,QAuthenticator*)));
+    if (httpReply->errorCode() != QNetworkReply::NoError) {
+        if (synchronous)
+            synchronousFinishedWithErrorSlot(httpReply->errorCode(), httpReply->errorString());
+        else
+            finishedWithErrorSlot(httpReply->errorCode(), httpReply->errorString());
+    }
 }
 
 // This gets called from the user thread or by the synchronous HTTP timeout timer