Fix redirecting POST for HTTP 307 and 308

All POST requests that were redirected would previously turn into GET
requests. This does not follow the standard for HTTP codes 307 and 308.

Task-number: QTBUG-63142
Change-Id: Ibd25a9566066e589670a9bc34e5dc5111f8139d5
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

3 files changed, 15 insertions, 2 deletions

diff --git a/src/network/access/qhttpmultipart.cpp b/src/network/access/qhttpmultipart.cpp
index 5c704efeef..870e71ba1e 100644
--- a/src/network/access/qhttpmultipart.cpp
+++ b/src/network/access/qhttpmultipart.cpp
@@ -483,6 +483,8 @@ bool QHttpMultiPartIODevice::isSequential() const
 
 bool QHttpMultiPartIODevice::reset()
 {
+    // Reset QIODevice's data
+    QIODevice::reset();
     for (int a = 0; a < multiPart->parts.count(); a++)
         if (!multiPart->parts[a].d->reset())
             return false;
diff --git a/src/network/access/qhttpnetworkconnectionchannel.cpp b/src/network/access/qhttpnetworkconnectionchannel.cpp
index e7bb8e6619..17520d0f4c 100644
--- a/src/network/access/qhttpnetworkconnectionchannel.cpp
+++ b/src/network/access/qhttpnetworkconnectionchannel.cpp
@@ -560,8 +560,14 @@ void QHttpNetworkConnectionChannel::handleStatus()
         if (redirectUrl.isValid())
             reply->setRedirectUrl(redirectUrl);
 
-        if (qobject_cast<QHttpNetworkConnection *>(connection))
+        if ((statusCode == 307 || statusCode == 308) && !resetUploadData()) {
+            // Couldn't reset the upload data, which means it will be unable to POST the data -
+            // this would lead to a long wait until it eventually failed and then retried.
+            // Instead of doing that we fail here instead, resetUploadData will already have emitted
+            // a ContentReSendError, so we're done.
+        } else if (qobject_cast<QHttpNetworkConnection *>(connection)) {
             QMetaObject::invokeMethod(connection, "_q_startNextRequest", Qt::QueuedConnection);
+        }
         break;
     }
     case 401: // auth required
diff --git a/src/network/access/qnetworkreplyhttpimpl.cpp b/src/network/access/qnetworkreplyhttpimpl.cpp
index 9756b43108..89d552f431 100644
--- a/src/network/access/qnetworkreplyhttpimpl.cpp
+++ b/src/network/access/qnetworkreplyhttpimpl.cpp
@@ -1115,10 +1115,15 @@ QNetworkAccessManager::Operation QNetworkReplyHttpImplPrivate::getRedirectOperat
     switch (currentOp) {
     case QNetworkAccessManager::HeadOperation:
         return QNetworkAccessManager::HeadOperation;
+    case QNetworkAccessManager::PostOperation:
+        // We MUST keep using POST when being redirected with 307 or 308.
+        if (statusCode == 307 || statusCode == 308)
+            return QNetworkAccessManager::PostOperation;
+        break;
     default:
         break;
     }
-    // For now, we're always returning GET for anything other than HEAD
+    // Use GET for everything else.
     return QNetworkAccessManager::GetOperation;
 }