Subscription fix for SessionItem in DistributionWidget.

GUI/coregui/Views/InfoWidgets/DistributionWidget.cpp

@@ -66,6 +66,12 @@ DistributionWidget::DistributionWidget(QWidget *parent)
     connect(m_plot, SIGNAL(mouseMove(QMouseEvent *)), this, SLOT(onMouseMove(QMouseEvent *)));
 }
 
+DistributionWidget::~DistributionWidget()
+{
+    if(m_item)
+        m_item->mapper()->unsubscribe(this);
+}
+
 void DistributionWidget::setItem(DistributionItem *item)
 {
     if (m_item == item) {
@@ -88,6 +94,11 @@ void DistributionWidget::setItem(DistributionItem *item)
             plotItem();
         }, this);
 
+        m_item->mapper()->setOnItemDestroy(
+                    [this](SessionItem *) {
+            m_item = 0;
+        }, this);
+
     }
 
 }

GUI/coregui/Views/InfoWidgets/DistributionWidget.h

@@ -37,6 +37,7 @@ class DistributionWidget : public QWidget
 
 public:
     DistributionWidget(QWidget *parent = 0);
+    ~DistributionWidget();
 
     void setItem(DistributionItem *item);
     void plotItem();