fixed crash on lambda changed on tg server

src/i0mapmon_topo.cpp

@@ -128,9 +128,11 @@ void I0mapmon_topo::m_onWlenSelectionChanged(QString wlen, bool on) {
 void I0mapmon_topo::m_onLambdaChanged(const QVector<double> &la) {
     printf("\e[1;32  I0mapmon_topo::m_onLambdaChanged >>>>>> IN <<<< \e[0m\n");
     QVector<double> current_l;
+    QMap<double, bool> prev_checked;
     for(int i = 0; m_cb_model != nullptr && i < m_cb_model->rowCount(); i++) {
         printf("\e[1;35mI0mapmon_topo::m_onLambdaChanged: row count %d item %d -> %s\e[0m\n", m_cb_model->rowCount(), i, qstoc(m_cb_model->item(i)->text()));
         current_l << m_cb_model->item(i)->text().toDouble();
+        prev_checked[current_l.last()] = m_cb_model->item(i)->data(Qt::CheckStateRole).toBool();
     }
     qDebug() << __PRETTY_FUNCTION__ << la << "current_l" << current_l;
     if(current_l != la) {
@@ -138,11 +140,11 @@ void I0mapmon_topo::m_onLambdaChanged(const QVector<double> &la) {
         QVector<int> wlens_idx;
         CheckableComboBoxModel *new_m = new CheckableComboBoxModel(this);
         for(int i = 0; i < la.size(); i++) {
-            bool checked = m_cb_model == nullptr || m_cb_model->findItem(la.at(i)) == nullptr || m_cb_model->findItem(la.at(i))->data(Qt::CheckStateRole).toBool();
+            bool checked = m_cb_model == nullptr || m_cb_model->findItem(la.at(i)) == nullptr || m_cb_model->findItem(la.at(i))->data(Qt::CheckStateRole).toBool() || prev_checked[la[i]];
             printf("I0mapmon_topo::m_onLambdaChanged \e[1;33m %f --> %d\e[0m m_cb_model %p \n", la[i], i, m_cb_model);
             if(m_cb_model) {
                 printf("       cb_model not null: found item %p for lam %f item count %d\n", m_cb_model->findItem(la.at(i)), la.at(i), m_cb_model->rowCount());
-                if(m_cb_model->findItem(la.at(i)), la.at(i))
+                if(m_cb_model->findItem(la.at(i)))
                     printf("             the item is checked? item : %s checked %d\n", qstoc(m_cb_model->findItem(la.at(i))->text()), m_cb_model->findItem(la.at(i))->data(Qt::CheckStateRole).toBool());
             }
             printf("checked is \e[1;32m%d\e[0m\n", checked);