QHttp2Configuration: in QNAM, use old, higher values in flow control

Initially, stream receive window's size was quite significant.
At some point when dealing with a server that did not want
our windows' sizes and was closing the connection (they only
accept 64K) we reduced this size, which ended in a regression
with download speed significantly throttled. We return the old
values (or even more, presuming we have 10 multiplexed streams
and not 100). And also making QNAM consistent with its documentation
(it was not updated).

[ChangeLog][QtNetwork] Stream receive window that HTTP/2 protocol in QNAM is using
increased to 214748364 octets (from the previous 64K) not to throttle download
speed. Clients, working with servers, not accepting such parameters,
must set HTTP/2 configuration on their requests accordingly.

Fixes: QTBUG-105043
Pick-to: 6.4 6.3 6.2
Change-Id: I252b6b5eefe92a7304dad15c67928d5a57d9597f
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/auto/network/access/http2/tst_http2.cpp b/tests/auto/network/access/http2/tst_http2.cpp
index bb2437c7f5..5525fd7630 100644
--- a/tests/auto/network/access/http2/tst_http2.cpp
+++ b/tests/auto/network/access/http2/tst_http2.cpp
@@ -69,6 +69,7 @@ public slots:
     void init();
 private slots:
     // Tests:
+    void defaultQnamHttp2Configuration();
     void singleRequest_data();
     void singleRequest();
     void multipleRequests();
@@ -208,6 +209,12 @@ void tst_Http2::init()
     manager.reset(new QNetworkAccessManager);
 }
 
+void tst_Http2::defaultQnamHttp2Configuration()
+{
+    // The configuration we also implicitly use in QNAM.
+    QCOMPARE(qt_defaultH2Configuration(), QNetworkRequest().http2Configuration());
+}
+
 void tst_Http2::singleRequest_data()
 {
     QTest::addColumn<QNetworkRequest::Attribute>("h2Attribute");