>From 8c97851cb499280bee035d835783bbf17943334e Mon Sep 17 00:00:00 2001
From: "rasmus.pank" <address@hidden>
Date: Sat, 1 Jun 2013 00:20:18 +0200
Subject: [PATCH] Allow AUTO argument to org-latex-guess-babel-language.

* ox-latex.el (org-latex-guess-babel-language): replace AUTO with
  language if AUTO is the option of the LaTeX package Babel.

* ox-latex.el (org-latex-guess-babel-language): retain case in final
replace-match of the function.
---
 lisp/ox-latex.el | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/lisp/ox-latex.el b/lisp/ox-latex.el
index ff0ca1d..0628514 100644
--- a/lisp/ox-latex.el
+++ b/lisp/ox-latex.el
@@ -910,6 +910,9 @@ Insertion of guessed language only happens when Babel package has
 explicitly been loaded.  Then it is added to the rest of
 package's options.
 
+The argument to Babel may be \"AUTO\" which is then replaced with
+the language of the document or `org-export-default-language'.
+
 Return the new header."
   (let ((language-code (plist-get info :language)))
     ;; If no language is set or Babel package is not loaded, return
@@ -918,16 +921,24 @@ Return the new header."
 	    (not (string-match "\\\\usepackage\\[\\(.*\\)\\]{babel}" header)))
 	header
       (let ((options (save-match-data
-		       (org-split-string (match-string 1 header) ",")))
+		       (org-split-string (match-string 1 header) ",[ \t]*")))
 	    (language (cdr (assoc language-code
 				  org-latex-babel-language-alist))))
-	;; If LANGUAGE is already loaded, return header.  Otherwise,
-	;; append LANGUAGE to other options.
-	(if (member language options) header
-	  (replace-match (mapconcat 'identity
-				    (append options (list language))
+	;; If LANGUAGE is already loaded, return header without AUTO.
+	;; Otherwise, replace AUTO with language or append language if
+	;; no AUTO is not present.
+	(replace-match (mapconcat 'identity
+				  (if language
+				      (cond ((member language options)
+					     (delete "AUTO") options)
+					    ((member "AUTO" options)
+					     (dotimes (n (length options) options)
+					       (if (equal "AUTO" (nth n options))
+						   (setf (nth n options) language))))
+					    (t (append options (list language))))
+				    (delete "AUTO" options))
 				    ",")
-			 nil nil header 1))))))
+				  t nil header 1)))))
 
 (defun org-latex--find-verb-separator (s)
   "Return a character not used in string S.
-- 
1.8.3