org-element: Fix affiliated keyword regexp

* lisp/org-element.el (org-element--affiliated-re): Fix affiliated
  keyword regexp.

lisp/org-element.el

@@ -239,19 +239,6 @@ application to open them.")
 By default, all keywords setting attributes (i.e. \"ATTR_LATEX\")
 are affiliated keywords and need not to be in this list.")
 
-(defconst org-element--affiliated-re
-  (format "[ \t]*#\\+%s:"
-	  ;; Regular affiliated keywords.
-	  (format "\\(%s\\|ATTR_[-_A-Za-z0-9]+\\)\\(?:\\[\\(.*\\)\\]\\)?"
-		  (regexp-opt org-element-affiliated-keywords)))
-  "Regexp matching any affiliated keyword.
-
-Keyword name is put in match group 1.  Moreover, if keyword
-belongs to `org-element-dual-keywords', put the dual value in
-match group 2.
-
-Don't modify it, set `org-element-affiliated-keywords' instead.")
-
 (defconst org-element-keyword-translation-alist
   '(("DATA" . "NAME")  ("LABEL" . "NAME") ("RESNAME" . "NAME")
     ("SOURCE" . "NAME") ("SRCNAME" . "NAME") ("TBLNAME" . "NAME")
@@ -298,6 +285,31 @@ This list is checked after translations have been applied.  See
 Any keyword in this list will have its value parsed and stored as
 a secondary string.")
 
+(defconst org-element--affiliated-re
+  (format "[ \t]*#\\+\\(?:%s\\):\\(?: \\|$\\)"
+	  (concat
+	   ;; Dual affiliated keywords.
+	   (format "\\(?1:%s\\)\\(?:\\[\\(.*\\)\\]\\)?"
+		   (regexp-opt org-element-dual-keywords))
+	   "\\|"
+	   ;; Regular affiliated keywords.
+	   (format "\\(?1:%s\\)"
+		   (regexp-opt
+		    (org-remove-if
+		     #'(lambda (keyword)
+			 (member keyword org-element-dual-keywords))
+		     org-element-affiliated-keywords)))
+	   "\\|"
+	   ;; Export attributes.
+	   "\\(?1:ATTR_[-_A-Za-z0-9]+\\)"))
+  "Regexp matching any affiliated keyword.
+
+Keyword name is put in match group 1.  Moreover, if keyword
+belongs to `org-element-dual-keywords', put the dual value in
+match group 2.
+
+Don't modify it, set `org-element-affiliated-keywords' instead.")
+
 (defconst org-element-object-restrictions
   (let* ((standard-set
 	  (remq 'plain-link (remq 'table-cell org-element-all-successors)))