Applied patch for #15189 - avoid crash when deleting focused cell (dghart)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74058 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/richtext/richtextbuffer.h

@@ -66,6 +66,7 @@
 #include "wx/cmdproc.h"
 #include "wx/txtstrm.h"
 #include "wx/variant.h"
+#include "wx/position.h"
 
 #if wxUSE_DATAOBJ
 #include "wx/dataobj.h"
@@ -5683,6 +5684,11 @@ public:
     */
     virtual bool GetCellRowColumnPosition(long pos, int& row, int& col) const;
 
+    /**
+        Returns the coordinates of the cell with keyboard focus, or (-1,-1) if none.
+    */    
+    virtual wxPosition GetFocusedCell() const;
+
 // Operations
 
     /**