Prevent crash when a python script tries to use pcbnew too early.

Fixes https://gitlab.com/kicad/code/kicad/-/issues/15414

pcbnew/pcb_edit_frame.cpp

@@ -108,6 +108,7 @@
 #include <footprint_viewer_frame.h>
 
 #include <action_plugin.h>
+#include <pcbnew_scripting_helpers.h>
 #include "../scripting/python_scripting.h"
 
 #include <wx/filedlg.h>
@@ -486,6 +487,8 @@ PCB_EDIT_FRAME::PCB_EDIT_FRAME( KIWAY* aKiway, wxWindow* aParent ) :
 
 PCB_EDIT_FRAME::~PCB_EDIT_FRAME()
 {
+    ScriptingOnDestructPcbEditFrame( this );
+
     if( ADVANCED_CFG::GetCfg().m_ShowEventCounters )
     {
         // Stop the timer during destruction early to avoid potential event race conditions (that

pcbnew/python/scripting/pcbnew_scripting_helpers.cpp

@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2012 NBEE Embedded Systems, Miguel Angel Ajo <miguelangel@nbee.es>
- * Copyright (C) 1992-2022 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 1992-2023 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -77,6 +77,13 @@ void ScriptingSetPcbEditFrame( PCB_EDIT_FRAME* aPcbEditFrame )
 }
 
 
+void ScriptingOnDestructPcbEditFrame( PCB_EDIT_FRAME* aPcbEditFrame )
+{
+    if( s_PcbEditFrame == aPcbEditFrame )
+        s_PcbEditFrame = nullptr;
+}
+
+
 BOARD* LoadBoard( wxString& aFileName )
 {
     if( aFileName.EndsWith( KiCadPcbFileExtension ) )

pcbnew/python/scripting/pcbnew_scripting_helpers.h

@@ -2,7 +2,7 @@
  * This program source code file is part of KiCad, a free EDA CAD application.
  *
  * Copyright (C) 2013 NBEE Embedded Systems SL, Miguel Angel Ajo <miguelangel@ajo.es>
- * Copyright (C) 2013-2021 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2013-2023 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -39,7 +39,8 @@ enum class EDA_UNITS;
  */
 
 #ifndef SWIG
-void    ScriptingSetPcbEditFrame( PCB_EDIT_FRAME* aPCBEdaFrame );
+void ScriptingSetPcbEditFrame( PCB_EDIT_FRAME* aPCBEdaFrame );
+void ScriptingOnDestructPcbEditFrame( PCB_EDIT_FRAME* aPCBEdaFrame );
 
 #endif