Refinement for fix in 5497.

pcbnew/pcbframe.cpp

@@ -467,6 +467,8 @@ PCB_EDIT_FRAME::~PCB_EDIT_FRAME()
 
 void PCB_EDIT_FRAME::SetBoard( BOARD* aBoard )
 {
+    bool new_board = ( aBoard != m_Pcb );
+
     PCB_BASE_FRAME::SetBoard( aBoard );
 
     if( IsGalCanvasActive() )
@@ -484,6 +486,8 @@ void PCB_EDIT_FRAME::SetBoard( BOARD* aBoard )
         {
             m_toolManager->SetEnvironment( aBoard, drawPanel->GetView(),
                                            drawPanel->GetViewControls(), this );
+
+            if( new_board )
                 m_toolManager->ResetTools( TOOL_BASE::MODEL_RELOAD );
         }
     }

pcbnew/tools/selection_tool.cpp

@@ -88,6 +88,15 @@ SELECTION_TOOL::~SELECTION_TOOL()
 
 void SELECTION_TOOL::Reset( RESET_REASON aReason )
 {
+    if( aReason == TOOL_BASE::MODEL_RELOAD )
+    {
+        // Remove pointers to the selected items from containers
+        // without changing their properties (as they are already deleted
+        // while a new board is loaded)
+        m_selection.group->Clear();
+        m_selection.clear();
+    }
+    else
         // Restore previous properties of selected items and remove them from containers
         clearSelection();