Attempt to fix destruction order crash (KICAD-6KC).

(cherry picked from commit a7fdea9b6f)

common/widgets/lib_tree.cpp

@@ -278,7 +278,20 @@ LIB_TREE::~LIB_TREE()
         m_details_ctrl->Unbind( wxEVT_HTML_LINK_CLICKED, &LIB_TREE::onDetailsLink, this );
 
     m_hoverTimer.Stop();
-    destroyPreview();
+}
+
+
+void LIB_TREE::ShutdownPreviews()
+{
+    m_hoverTimer.Stop();
+    m_previewDisabled = true;
+
+    if( m_previewWindow )
+    {
+        m_previewWindow->Hide();
+        m_previewWindow->Destroy();
+        m_previewWindow = nullptr;
+    }
 }
 
 
@@ -751,18 +764,6 @@ void LIB_TREE::hidePreview()
 }
 
 
-void LIB_TREE::destroyPreview()
-{
-    hidePreview();
-
-    if( m_previewWindow )
-    {
-        m_previewWindow->Destroy();
-        m_previewWindow = nullptr;
-    }
-}
-
-
 void LIB_TREE::onIdle( wxIdleEvent& aEvent )
 {
     // The wxDataViewCtrl won't give us its mouseMoved events so we're forced to use idle

eeschema/symbol_editor/symbol_edit_frame.cpp

@@ -688,6 +688,9 @@ bool SYMBOL_EDIT_FRAME::canCloseWindow( wxCloseEvent& aEvent )
 
 void SYMBOL_EDIT_FRAME::doCloseWindow()
 {
+    if( GetLibTree() )
+        GetLibTree()->ShutdownPreviews();
+
     Destroy();
 }
 

include/widgets/lib_tree.h

@@ -180,6 +180,8 @@ public:
         m_previewDisabled = aBlock;
     }
 
+    void ShutdownPreviews();
+
 protected:
     /**
      * Expand or collapse a node, switching it to the opposite state.
@@ -232,7 +234,6 @@ protected:
 
     void showPreview( wxDataViewItem aItem );
     void hidePreview();
-    void destroyPreview();
 
     void onQueryText( wxCommandEvent& aEvent );
     void onQueryCharHook( wxKeyEvent& aEvent );

pcbnew/footprint_edit_frame.cpp

@@ -941,6 +941,9 @@ void FOOTPRINT_EDIT_FRAME::doCloseWindow()
     GetCanvas()->SetEventDispatcher( nullptr );
     GetCanvas()->StopDrawing();
 
+    if( GetLibTree() )
+        GetLibTree()->ShutdownPreviews();
+
     // Do not show the layer manager during closing to avoid flicker
     // on some platforms (Windows) that generate useless redraw of items in
     // the Layer Manager