From 9277e633527928b7c10a955ccdf4fd15cd9d7487 Mon Sep 17 00:00:00 2001
From: Nicolas Goaziou <mail@nicolasgoaziou.fr>
Date: Sat, 24 Oct 2015 11:37:46 +0200
Subject: [PATCH] ob-core: Fix "wrong-type-argument stringp nil"

* lisp/ob-core.el (org-babel-merge-params): Tolerate empty :exports
  parameter.

Reported-by: Rainer M Krug <Rainer@krugs.de>
<http://permalink.gmane.org/gmane.emacs.orgmode/102005>
---
 lisp/ob-core.el | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index 61753ce70..902315a20 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -2551,7 +2551,8 @@ parameters when merging lists."
 	       (setq params (cons pair (assq-delete-all (car pair) params)))))
 	    (:exports
 	     (setq exports (funcall e-merge exports-exclusive-groups
-				    exports (split-string (cdr pair)))))
+				    exports
+				    (split-string (or (cdr pair) "")))))
 	    (:tangle ;; take the latest -- always overwrite
 	     (setq tangle (or (list (cdr pair)) tangle)))
 	    (:noweb