Uploading files via HTTP/POST using QHttpMultiPart, no longer working

[GregB]

I have an application that uploads files to an http server. The application was working correctly until I upgraded the Qt version from 5.5.0 to 5.5.1.

Basically, after doing the networkmanager->post() operation, it never receives signals (finished, error, uploadprogress). So my application just waits for the signals which never come.

I have other form submission in my application which doesn't submit files, but those work just fine. I submit the form, and either the finished or error signals get called.

This is the abbreviated code for my file upload, which used to work, but now doesn't

QUrl url(connServer + "/api.php");
QNetworkRequest request(url);
QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
QHttpPart loginPart;
/* username */
loginPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"u\""));
loginPart.setBody(connUsername.toLatin1());
multiPart->append(loginPart);
/* password */
loginPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"p\""));
loginPart.setBody(connPassword.toLatin1());
multiPart->append(loginPart);
/* loop through the list of files */
ui->progUpload->setRange(0,100);
for (int i=0;i<list.size();i++) {
	QFile *file = new QFile(list[i]);
	QHttpPart filePart;
	filePart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"files[]\"; filename=\""+ file->fileName() + "\""));

	file->open(QIODevice::ReadOnly);
	filePart.setBodyDevice(file);
	file->setParent(multiPart); // we cannot delete the file now, so delete it with the multiPart
	multiPart->append(filePart);
}

while (isUploading) {
	ui->lblStatus->setText("Waiting for response from server");
	QTest::qWait(1000);
}
QNetworkReply* reply = networkManager->post(request, multiPart);
multiPart->setParent(reply); // delete the multiPart with the reply
connect(reply, SIGNAL(finished()), this, SLOT(onGetReplyUpload()));
connect(reply, SIGNAL(error(QNetworkReply::NetworkError)), this, SLOT(onNetworkError(QNetworkReply::NetworkError)));
connect(reply, SIGNAL(uploadProgress(qint64, qint64)), SLOT(progressChanged(qint64, qint64)));

This doesn't submit files with the form, and it still works fine:

QUrl url(connServer + "/api.php");
QNetworkRequest request(url);
QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
QHttpPart loginPart;
/* username */
loginPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"u\""));
loginPart.setBody(connUsername.toLatin1()); multiPart->append(loginPart);
/* password */
loginPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"p\""));
loginPart.setBody(connPassword.toLatin1()); multiPart->append(loginPart);
/* action */
loginPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"action\""));
loginPart.setBody("startTransaction"); multiPart->append(loginPart);
QNetworkReply* reply = networkManager->post(request, multiPart);
multiPart->setParent(reply); // delete the multiPart with the reply
connect(reply, SIGNAL(finished()), this, SLOT(onGetReplyStartTransaction()));

[GregB]

Figured out more details: The problem only occurs on Windows 10, and is not related to the Qt version.

[SGaist]

Hi and welcome to devnet,

Can you check if that still happens with Qt 5.6 Beta ?