Footprint chooser: fix crash when closing the dialog with a large footprint.

The crash was perhaps due to use after delete of data in DTOR functions, when
a footprint with a **lot** of graphics was loaded and the view cleared.
The view is now cleared before any other deletion.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/20915

pcbnew/footprint_chooser_frame.cpp

@@ -236,6 +236,9 @@ FOOTPRINT_CHOOSER_FRAME::~FOOTPRINT_CHOOSER_FRAME()
     m_preview3DCanvas->Show();
     m_preview3DCanvas->OnCloseWindow( dummy );
 
+    // Ensure view and data used by the preview panel are cleared before deleting other items
+    static_cast<FOOTPRINT_PREVIEW_PANEL*>( m_chooserPanel->GetViewerPanel()->GetPreviewPanel() )->ClearViewAndData();
+
     // Disconnect board, which is owned by FOOTPRINT_PREVIEW_PANEL.
     m_pcb = nullptr;
 

pcbnew/footprint_preview_panel.cpp

@@ -47,6 +47,7 @@
 #include <dialog_shim.h>
 #include <project_pcb.h>
 
+
 FOOTPRINT_PREVIEW_PANEL::FOOTPRINT_PREVIEW_PANEL( KIWAY* aKiway, wxWindow* aParent,
                                                   UNITS_PROVIDER* aUnitsProvider,
                                                   std::unique_ptr<KIGFX::GAL_DISPLAY_OPTIONS> aOpts,
@@ -75,6 +76,12 @@ FOOTPRINT_PREVIEW_PANEL::FOOTPRINT_PREVIEW_PANEL( KIWAY* aKiway, wxWindow* aPare
 
 
 FOOTPRINT_PREVIEW_PANEL::~FOOTPRINT_PREVIEW_PANEL( )
+{
+    ClearViewAndData();
+}
+
+
+void FOOTPRINT_PREVIEW_PANEL::ClearViewAndData()
 {
     m_dummyBoard->DetachAllFootprints();
 
@@ -85,6 +92,9 @@ FOOTPRINT_PREVIEW_PANEL::~FOOTPRINT_PREVIEW_PANEL( )
         GetView()->Remove( m_otherFootprint.get() );
 
     GetView()->Clear();
+
+    m_currentFootprint = nullptr;
+    m_otherFootprint = nullptr;
 }
 
 

pcbnew/footprint_preview_panel.h

@@ -76,6 +76,11 @@ public:
                                          UNITS_PROVIDER* aUnitsProvider );
     FOOTPRINT* GetCurrentFootprint() const { return m_currentFootprint.get(); }
 
+    /* Delete loaded footprints and clear view
+     * Must be called before deleting the panel
+     */
+    void ClearViewAndData();
+
 private:
     /**
      * Create a new panel