Method realloc_with_extra_if_needed

sql/sql_string.h:764–772

    return FALSE;
  }
  bool realloc_with_extra_if_needed(size_t arg_length)
  {
    if (arg_length < Alloced_length)
    {
      Ptr[arg_length]=0; // behave as if realloc was called.
      return 0;
    }
    return realloc_with_extra(arg_length);
  }
  // Shrink the buffer, but only if it is allocated on the heap.
  void shrink(size_t arg_length);