Schematic editor: fix some issues that can crash the editor on closing.

- Add a test to be sure a SCHEMATIC exists before trying to use it
- Delete items in Repeat list and undo/redo list before deleting the schematic
- Delete also these items when loading a new schematic (the repeat list was
not cleaned previously)
Before these fixes I see a use after delete issue due to dangling pointers
stored in Repeat list.

eeschema/files-io.cpp

@@ -147,6 +147,7 @@ bool SCH_EDIT_FRAME::OpenProjectFiles( const std::vector<wxString>& aFileSet, in
     // unload current project file before loading new
     {
         ClearUndoRedoList();
+        ClearRepeatItemsList();
         SetScreen( nullptr );
         m_toolManager->GetTool<EE_INSPECTION_TOOL>()->Reset( TOOL_BASE::SUPERMODEL_RELOAD );
         CreateScreens();
@@ -748,6 +749,7 @@ void SCH_EDIT_FRAME::OnImportProject( wxCommandEvent& aEvent )
     // Don't leave dangling pointers to previously-opened document.
     m_toolManager->GetTool<EE_SELECTION_TOOL>()->ClearSelection();
     ClearUndoRedoList();
+    ClearRepeatItemsList();
 
     if( setProject )
     {
@@ -1472,6 +1474,7 @@ bool SCH_EDIT_FRAME::importFile( const wxString& aFileName, int aFileType,
         }
 
         ClearUndoRedoList();
+        ClearRepeatItemsList();
 
         initScreenZoom();
         SetSheetNumberAndCount();

eeschema/sch_edit_frame.cpp

@@ -442,6 +442,11 @@ SCH_EDIT_FRAME::~SCH_EDIT_FRAME()
     if( m_schematic )
         m_schematic->RemoveAllListeners();
 
+    // Delete all items not in draw list before deleting schematic
+    // to avoid dangling pointers stored in these items
+    ClearUndoRedoList();
+    ClearRepeatItemsList();
+
     delete m_schematic;
     m_schematic = nullptr;
 

eeschema/sch_edit_frame.h

@@ -715,6 +715,15 @@ public:
         return m_items_to_repeat;
     }
 
+    /**
+     * Clear the list of items which are to be repeated with the insert key.
+     * These objects are owned by this container.
+     */
+    void ClearRepeatItemsList()
+    {
+        m_items_to_repeat.clear();
+    }
+
     EDA_ITEM* GetItem( const KIID& aId ) const override;
 
     /**

eeschema/sch_item.cpp

@@ -144,6 +144,11 @@ SCH_ITEM* SCH_ITEM::Duplicate( bool doClone ) const
 
 SCHEMATIC* SCH_ITEM::Schematic() const
 {
+    if( !SCHEMATIC::m_IsSchematicExists )
+    {
+        return nullptr;
+    }
+
     EDA_ITEM* parent = GetParent();
 
     while( parent )

eeschema/schematic.cpp

@@ -37,6 +37,8 @@
 #include <sim/spice_value.h>
 #include <netlist_exporter_spice.h>
 
+bool SCHEMATIC::m_IsSchematicExists = false;
+
 SCHEMATIC::SCHEMATIC( PROJECT* aPrj ) :
           EDA_ITEM( nullptr, SCHEMATIC_T ),
           m_project( nullptr ),
@@ -44,6 +46,7 @@ SCHEMATIC::SCHEMATIC( PROJECT* aPrj ) :
 {
     m_currentSheet    = new SCH_SHEET_PATH();
     m_connectionGraph = new CONNECTION_GRAPH( this );
+    m_IsSchematicExists = true;
 
     SetProject( aPrj );
 
@@ -124,6 +127,8 @@ SCHEMATIC::~SCHEMATIC()
 
     delete m_currentSheet;
     delete m_connectionGraph;
+
+    m_IsSchematicExists = false;
 }
 
 

eeschema/schematic.h

@@ -305,6 +305,11 @@ public:
      */
     void RemoveAllListeners();
 
+    /**
+     * True if a SCHEMATIC exists, false if not
+     */
+    static bool m_IsSchematicExists;
+
 #if defined(DEBUG)
     void Show( int nestLevel, std::ostream& os ) const override {}
 #endif