No buffer file name when exporting in org mode

[Yevgnen]

The line here checks the buffer-file-name. When exporting in org-mode, the it seems that a indirect buffer is created and with no buffer file name which emits an error.

#+BEGIN_SRC cython
  cdef int i
  cdef float k
#+END_SRC

Error:

Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
  replace-regexp-in-string("[^-0-9a-zA-Z_./\n]" "\\\\\\&" nil)
  shell-quote-argument(nil)
  cython-mode()
  org-html-fontify-code("cdef int i\ncdef float k" "cython")
  org-html-do-format-code("cdef int i\ncdef float k" "cython" nil t nil)
  ...
  org-export-to-file(html "./cython.html" nil nil nil nil nil)
  org-html-export-to-html(nil nil nil nil)
  (org-open-file (org-html-export-to-html nil s v b))
  (if a (org-html-export-to-html t s v b) (org-open-file (org-html-export-to-html nil s v b)))
  (lambda (a s v b) (if a (org-html-export-to-html t s v b) (org-open-file (org-html-export-to-html nil s v b))))(nil nil nil nil)
  org-export-dispatch(nil)
  funcall-interactively(org-export-dispatch nil)
  call-interactively(org-export-dispatch nil nil)
  command-execute(org-export-dispatch)