Disabling HTTP2 Upgrade

[hsfougaris]

I upgraded a project that was using the previous version with Qt5, as I am trying to convert my project to Qt6.
So now with KDSOAP 2, I have a problem with the target server, as I see in the header the introduction of the HTTP2 upgrade tag.
Is there a way to disable sending the upgrade offer tag? I think the server is supposed to ignore it, but it doesn't and logs it as an invalid tag (forbidden protocol upgrade to h2c).
I cannot really change the server, so is it something we can control in the library ?
Is it maybe a Qt6 thing ?
thank you

[dfaure-kdab]

It is for sure a Qt6 thing, nothing else changed in KDSoap, and this is handled by QNetworkAccessManager.
The next step is to look at QNetworkAccessManager docs to see which control it offers over that kind of thing, and then we can add similar methods to KDSoapClientInterface.

[hsfougaris]

Thank you for the quick reply.
It seems you are right, https://www.qt.io/blog/qt-network-in-qt-6
"In Qt 6, HTTP/2 support is enabled by default: this means the attribute 'Http2AllowedAttribute' is set to true"

[dfaure-kdab]

I wonder if KDSoap shouldn't just set it to false unconditionally... I just did some googling around about SOAP and HTTP/2, and it doesn't seem to be a common combination at all. In fact the HTTP/2 FAQ says they are mostly targeting the browser use case, not APIs over HTTP. Although I guess the binary protocol would be good for performance. But whether any SOAP servers support HTTP/2 is another story...

Let's just disable it for now and see if anyone requests it ;)

[hsfougaris]

That's kind of what I did temporarily.
In KDSoapClientInterface.cpp, after line 91
QNetworkRequest request(QUrl(this->m_endPoint));
I added:
request.setAttribute(QNetworkRequest::Http2AllowedAttribute, false);

Seems to work like a charm!

Thank you

[dfaure-kdab]

Great, that's also what I just did ;)
Thanks for the testing, pushed.