Network: Fix up previous corruption patch

This is a fix-up for cff39fba10ffc10ee4dcfdc66ff6528eb26462d3.
That patch lead to some internal state issues that lead to the QTBUG-47048
or to QNetworkReply objects erroring with "Connection Closed" when
the server closed the Keep-Alive connection.

This patch changes the QNAM socket slot connections to be DirectConnection.
We don't close the socket anymore in slots where it is anyway in a closed state
afterwards. This prevents event/stack recursions.
We also flush QSslSocket/QTcpSocket receive buffers when receiving a disconnect
so that the developer always gets the full decrypted data from the buffers.

[ChangeLog][QtNetwork] Fix HTTP issues with "Unknown Error" and "Connection Closed"
[ChangeLog][QtNetwork][Sockets] Read OS/encrypted read buffers when connection
closed by server.

Change-Id: Ib4d6a2d0d988317e3a5356f36e8dbcee4590beed
Task-number: QTBUG-47048
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>
Reviewed-by: Richard J. Moore <rich@kde.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/network/ssl/qsslsocket_openssl.cpp b/src/network/ssl/qsslsocket_openssl.cpp
index ac4336afcc..94655feb9b 100644
--- a/src/network/ssl/qsslsocket_openssl.cpp
+++ b/src/network/ssl/qsslsocket_openssl.cpp
@@ -1419,6 +1419,13 @@ void QSslSocketBackendPrivate::disconnected()
 {
     if (plainSocket->bytesAvailable() <= 0)
         destroySslContext();
+    else {
+        // Move all bytes into the plain buffer
+        qint64 tmpReadBufferMaxSize = readBufferMaxSize;
+        readBufferMaxSize = 0; // reset temporarily so the plain socket buffer is completely drained
+        transmit();
+        readBufferMaxSize = tmpReadBufferMaxSize;
+    }
     //if there is still buffered data in the plain socket, don't destroy the ssl context yet.
     //it will be destroyed when the socket is deleted.
 }