Pcbnew: fix dangling board reference crash in GAL. (fixes lp:1584489)

common/tool/tool_manager.cpp

@@ -427,11 +427,15 @@ TOOL_BASE* TOOL_MANAGER::FindTool( const std::string& aName ) const
     return NULL;
 }
 
-
-void TOOL_MANAGER::ResetTools( TOOL_BASE::RESET_REASON aReason )
+void TOOL_MANAGER::DeactivateTool()
 {
     TOOL_EVENT evt( TC_COMMAND, TA_ACTIVATE, "" );      // deactivate the active tool
     ProcessEvent( evt );
+}
+
+void TOOL_MANAGER::ResetTools( TOOL_BASE::RESET_REASON aReason )
+{
+    DeactivateTool();
 
     for( TOOL_BASE* tool : m_toolState | boost::adaptors::map_keys )
     {

include/tool/tool_manager.h

@@ -186,6 +186,12 @@ public:
         return NULL;
     }
 
+    /**
+     * Function DeactivateTool()
+     * Deactivates the currently active tool.
+     */
+    void DeactivateTool();
+
     /**
      * Function ResetTools()
      * Resets all tools (i.e. calls their Reset() method).

pcbnew/pcb_base_edit_frame.cpp

@@ -68,6 +68,10 @@ void PCB_BASE_EDIT_FRAME::SetBoard( BOARD* aBoard )
 {
     bool new_board = ( aBoard != m_Pcb );
 
+    // The active tool might store a reference to the BOARD that is about to be deleted.
+    if( m_toolManager )
+        m_toolManager->DeactivateTool();
+
     // It has to be done before the previous board is destroyed by SetBoard()
     if( new_board )
         GetGalCanvas()->GetView()->Clear();