jfjoch_viewer: Tracing potential problem in dataset info chart view

viewer/charts/JFJochDatasetInfoChartView.cpp

@@ -22,7 +22,7 @@ JFJochDatasetInfoChartView::JFJochDatasetInfoChartView(QWidget *parent)
 
 
 void JFJochDatasetInfoChartView::setImage(int64_t val) {
-    if (!currentSeries)
+    if (!currentSeries || currentSeries->chart() != chart())
         return;
 
     curr_image = val;
@@ -129,7 +129,12 @@ void JFJochDatasetInfoChartView::resetZoom() {
 }
 
 void JFJochDatasetInfoChartView::updateChart() {
+    // Important: drop any stale QObject pointers BEFORE rebuilding the chart.
+    series = nullptr;
+    currentSeries = nullptr;
+
     chart()->removeAllSeries();
+
     if (m_hoverLine) {
         chart()->scene()->removeItem(m_hoverLine);
         delete m_hoverLine;

viewer/charts/JFJochDatasetInfoChartView.h

@@ -11,6 +11,7 @@
 #include <QMouseEvent>
 #include <QGraphicsLineItem>
 #include <QTimer>
+#include <QPointer>
 
 #ifdef JFJOCH_USE_FFTW
 #include <fftw3.h>
@@ -22,8 +23,8 @@
 class JFJochDatasetInfoChartView : public QChartView {
     Q_OBJECT
 
-    QLineSeries *series = nullptr;
-    QScatterSeries *currentSeries = nullptr;
+    QPointer<QLineSeries> series = nullptr;
+    QPointer<QScatterSeries> currentSeries = nullptr;
     QGraphicsLineItem *m_hoverLine = nullptr;
     QTimer *m_hoverLoadTimer = nullptr;
     int64_t m_hoverPendingIdx = -1;