[Bug fortran/67526] ICE on missing end parenthesis in substring construct

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67526

--- Comment #3 from kargl at gcc dot gnu.org ---
Created attachment 36314
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36314&action=edit
patch

The attached patch fixes the dereference of a NULL pointer.