Qt documentation states:
void QNetworkReply::error(QNetworkReply::NetworkError code) [signal]
This signal is emitted when the reply detects an error in processing. The finished() signal will probably follow, indicating that the connection is over.
From what I've seen in Qt sources (was checking absolutely same issue recently), everywhere after error(), there is a finished() call afterwards. In 5.1.0 I haven't found a place where error is not followed by finished()
for example
void QNetworkReplyImpl::close()
{
Q_D(QNetworkReplyImpl);
if (d->state == QNetworkReplyImplPrivate::Aborted ||
d->state == QNetworkReplyImplPrivate::Finished)
return;
// stop the download
if (d->backend)
d->backend->closeDownstreamChannel();
if (d->copyDevice)
disconnect(d->copyDevice, 0, this, 0);
QNetworkReply::close();
// call finished which will emit signals
d->error(OperationCanceledError, tr("Operation canceled"));
d->finished();
}