Even if QNetworkRequest :: setDecompressedSafetyCheckThreshold (-1) is specified, the Content-Type of the response data is prioritized and decompressed.

As a result, even if you post to the server, if you receive data of (10 * 1024 * 1024) bytes or more, it will be decompressed without permission, and it will not be the data you expect.

After changing to the following processing, the expected behavior was obtained.

bool QDecompressHelper::isValid() const
{
    return archiveBombCheckThreshold != std::numeric_limits<qint64>::max() && contentEncoding != None;
}