QHttp2Stream: append message data before dataReceived()

... so that there is a way to access downloadBuffer() /
takeDownloadBuffer() when the signal is emitting and not afterwards.

Add the 'last()' functionality (c.f. QList::last) so that we can get a
cheap reference to the just inserted buffer entry.

Task-number: QTBUG-142473
Pick-to: 6.11 6.10 6.8
Change-Id: I263322ec8a83cd29294b60c139a1ec3dab698ecb
Reviewed-by: Mate Barany <[email protected]>
Reviewed-by: Mårten Nordheim <[email protected]>
Reviewed-by: Alexey Edelev <[email protected]>

2 files changed, 10 insertions, 2 deletions

diff --git a/src/network/access/qbytedatabuffer_p.h b/src/network/access/qbytedatabuffer_p.h
index a119093cf7e..036b562d06a 100644
--- a/src/network/access/qbytedatabuffer_p.h
+++ b/src/network/access/qbytedatabuffer_p.h
@@ -280,6 +280,8 @@ public:
         }
         return false;
     }
+
+    const QByteArray &last() const { return buffers.last(); }
 };
 
 QT_END_NAMESPACE
diff --git a/src/network/access/qhttp2connection.cpp b/src/network/access/qhttp2connection.cpp
index 2895e8335d2..3f88318bb17 100644
--- a/src/network/access/qhttp2connection.cpp
+++ b/src/network/access/qhttp2connection.cpp
@@ -697,8 +697,14 @@ void QHttp2Stream::handleDATA(const Frame &inboundFrame)
                             inboundFrame.dataSize());
         if (endStream)
             transitionState(StateTransition::CloseRemote);
-        emit dataReceived(fragment, endStream);
-        m_downloadBuffer.append(std::move(fragment));
+        const auto shouldBuffer = !fragment.isEmpty();
+        if (shouldBuffer) {
+            // Only non-empty fragments get appended!
+            m_downloadBuffer.append(std::move(fragment));
+            emit dataReceived(m_downloadBuffer.last(), endStream);
+        } else {
+            emit dataReceived(fragment, endStream);
+        }
     }
 
     if (!endStream && m_recvWindow < connection->streamInitialReceiveWindowSize / 2) {