Crashfix: closing and reopening popup palette

BUG:443402


(cherry picked from commit 626dec9f)

libs/ui/kis_popup_palette.cpp

@@ -120,6 +120,9 @@ KisPopupPalette::KisPopupPalette(KisViewManager* viewManager, KisCoordinatesConv
     connect(m_resourceManager, SIGNAL(updatePalettes()), this, SLOT(slotUpdate()));
     connect(m_resourceManager, SIGNAL(hidePalettes()), this, SIGNAL(finished()));
 
+    // Instances of `this` rely on finished() to be detached and its lifetime is associated with `parent`
+    connect(parent, SIGNAL(destroyed(QObject *)), this, SIGNAL(finished()), Qt::DirectConnection);
+
     setCursor(Qt::ArrowCursor);
     setMouseTracking(true);
     setHoveredPreset(-1);

libs/ui/kis_popup_palette.h

@@ -182,7 +182,7 @@ Q_SIGNALS:
     void sigChangefGColor(const KoColor&);
     void sigUpdateCanvas();
     void zoomLevelChanged(int);
-    void finished(); // KisPopupWidgetInterface.
+    void finished() override; // KisPopupWidgetInterface.
 
 public Q_SLOTS:
     void slotUpdateIcons();