Files getting corrupted when being downloaded using QNetworkAcessManager - qt

Question

I'm developing a client app whose purpose is to download some files from a web server, temporarily store them in the Temp folder, check for file integrity, then send them to a FTP server in a Embedded Linux device.
Recently I got problems when doing the process in a preliminary development stage when I was trying to do the download from my local machine (see related question here). Now I'm able to download and upload without errors and with verification (I'm using QCryptographicHash + file size to check for any nonconformities) from my machine, but the same doesn't happen when I try downloading from the HTTP server.
There is a total of 8 files being downloaded: three .tar.gz, one simple text, two programs and two binaries. I'm able to successfully download all compressed files, the text file and one of the binaries, but the others, namely the two programs and one of the binaries (a Linux Kernel image) are always being incorrectly downloaded.
I check this by noticing not only that the hash returns error for them, but also for their sizes: their sizes are always wrong (and always the same erroneous value for any download attempt). And the files in the server are all correct.
My first suspicion was that I need to configure the HTTP download in a way that differs from the common FTP download from the local machine, but I'm unaware on how would that be. Moreover if this extra configuration was needed, then why some of the files always return correctly?
Here is the relevant code as for now:
void MainWindow::processNextDownload()
{
QUrl ulrTemp(updateData.at(transferStep).downloadUrl.arg(ui->leID->text())); //"//" +
if (updateData.at(transferStep).downloadUrl.contains("http"))
ulrTemp.setScheme("http");
else
ulrTemp.setScheme("file");
// ulrTemp.setUserName();
// ulrTemp.setPassword();
// ulrTemp.setPort();
qDebug() << "Downloading" << transferStep << "from" << ulrTemp;
#if 1
poReply = downloadNetworkManager->get(QNetworkRequest(ulrTemp));
#else
QNetworkRequest request;
request.setUrl(ulrTemp);
request.setRawHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1312.60 Safari/537.17");
poReply = downloadNetworkManager->get(request);
#endif
connect(poReply,SIGNAL(downloadProgress(qint64,qint64)),this,SLOT(slotDownloadProgress(qint64,qint64)));
ui->statusBar->showMessage(tr("Downloading: %1").arg(updateData.at(transferStep).itemName));
}
void MainWindow::slotFileDownloaded(QNetworkReply* reply)
{
if (reply && (reply->error() != QNetworkReply::NoError))
{
ui->statusBar->clearMessage();
if (!isSingleFile)
{
const QString strTemp = tr("An error occurred while downloading \"%1\": %2 (error message: %3)")
.arg(updateData.at(transferStep).downloadName).arg(reply->error()).arg(reply->errorString());
QMessageBox::critical(this,tr("Error in download"),strTemp);
}
else
{
//irrelevant...
}
finished(false);
return;
}
qDebug() << "To write: " << reply->bytesAvailable();
QByteArray downloadedData = reply->readAll();
reply->deleteLater();
poReply->deleteLater();
//![]
static const QString tempFilePath = QDir::tempPath();
if (!isSingleFile)
{
QFile file(tempFilePath + "/" + updateData.at(transferStep).downloadName);
if (!file.open(QFile::WriteOnly | QFile::Truncate))
{
qDebug() << "Failure opening temp file to write: " << file.fileName();
QMessageBox::critical(this,
tr("Error"),
tr("An error occured while trying to open a temporary file to write the downloaded data (file: %1).").arg(file.fileName()));
transferStep = downloadStepCount;
slotFileUploaded(NULL);
return;
}
qint32 bytesWritten = file.write(downloadedData);
file.flush();
if (downloadedData.size() != bytesWritten)
qDebug() << "Write failed, wrote" << bytesWritten << "out of" << downloadedData.size() << "bytes.";
else
qDebug() << "Wrote " << bytesWritten << "bytes.";
file.close();
//![]
if (++transferStep >= downloadStepCount)
{
qDebug() << "Start hash check";
slotStartHashCheck();
return;
}
processNextDownload();
}
else
{
//irrelevant...
}
}
And this is why I get (the last number value after the "=" in the hash code is the file size):
So what am I missing?