behaviour of org-export--get-subtree-options vs inbuffer-options

[Per Unneberg <punneberg@gmail.com>]

Hi list,

on exporting subtrees to latex, I've noticed that inserting several
EXPORT_LATEX_HEADER_EXTRA does not do what I naively had expected; that
each entry be inserted in the header, separated by a newline, along with
document properties (#+LATEX_HEADER et al). Looking closer at
org-export--get-subtree-options and comparing to
org-export--get-inbuffer-options suggests that the former doesn't take
into account multiple EXPORT_LATEX_HEADER* statements?

Here is a MWE to show what I mean. Exporting the following document with
C-c C-e l L inserts all lines in the preamble

#+LATEX_HEADER: %%latex_header_1
#+LATEX_HEADER: %%latex_header_2
#+LATEX_HEADER_EXTRA: %%latex_header_extra_1
#+LATEX_HEADER_EXTRA: %%latex_header_extra_2

* Latex test
  :PROPERTIES:
  :EXPORT_LATEX_HEADER_EXTRA: %%subtree-latex-header-extra-1
  :EXPORT_LATEX_HEADER_EXTRA: %%subtree-latex-header-extra-2
  :EXPORT_LATEX_HEADER: %%subtree-latex-header-1
  :EXPORT_LATEX_HEADER: %%subtree-latex-header-2
  :END:

However, running C-c C-e C-s l L on the subtree removes the
%%latex_header_* and inserts only the first subtree-latex statements
(extra-1, header-1). 

Is this the intended behaviour?

Cheers,

Per