Fix client lifecycle in the open62541 backend

- Don't leak the client when calling connectToEndpoint more than once.
- Don't segfault when trying to disconnect without a client.

This also removes the memory leaks in the test cases.

Change-Id: I0405a86e9015465b86cc94facac6e8676b4039a7
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>
Reviewed-by: Frank Meerkoetter <frank.meerkoetter@basyskom.com>

1 files changed, 13 insertions, 6 deletions

diff --git a/src/plugins/opcua/open62541/qopen62541backend.cpp b/src/plugins/opcua/open62541/qopen62541backend.cpp
index 24aedf8..ec0eb09 100644
--- a/src/plugins/opcua/open62541/qopen62541backend.cpp
+++ b/src/plugins/opcua/open62541/qopen62541backend.cpp
@@ -75,6 +75,8 @@ Open62541AsyncBackend::Open62541AsyncBackend(QOpen62541Client *parent)
 Open62541AsyncBackend::~Open62541AsyncBackend()
 {
     qDeleteAll(m_subscriptions);
+    if (m_uaclient)
+        UA_Client_delete(m_uaclient);
 }
 
 void Open62541AsyncBackend::readAttributes(uintptr_t handle, UA_NodeId id, QOpcUa::NodeAttributes attr, QString indexRange)
@@ -432,6 +434,9 @@ static void clientStateCallback(UA_Client *client, UA_ClientState state)
 
 void Open62541AsyncBackend::connectToEndpoint(const QUrl &url)
 {
+    if (m_uaclient)
+        UA_Client_delete(m_uaclient);
+
     UA_ClientConfig conf = UA_ClientConfig_default;
     conf.clientContext = this;
     conf.stateCallback = &clientStateCallback;
@@ -464,14 +469,16 @@ void Open62541AsyncBackend::disconnectFromEndpoint()
     m_subscriptions.clear();
     m_attributeMapping.clear();
 
-    UA_StatusCode ret = UA_Client_disconnect(m_uaclient);
-    if (ret != UA_STATUSCODE_GOOD) {
-        qCWarning(QT_OPCUA_PLUGINS_OPEN62541) << "Open62541: Failed to disconnect";
-        // Fall through intentionally
+    if (m_uaclient) {
+        UA_StatusCode ret = UA_Client_disconnect(m_uaclient);
+        if (ret != UA_STATUSCODE_GOOD) {
+            qCWarning(QT_OPCUA_PLUGINS_OPEN62541) << "Open62541: Failed to disconnect";
+            // Fall through intentionally
+        }
+        UA_Client_delete(m_uaclient);
+        m_uaclient = nullptr;
     }
 
-    UA_Client_delete(m_uaclient);
-    m_uaclient = nullptr;
     emit stateAndOrErrorChanged(QOpcUaClient::Disconnected, QOpcUaClient::NoError);
 }