Make #+BIND work correctly, and ask the user to confirm using BIND.

doc/org.texi

@@ -8485,6 +8485,7 @@ Insert template with export options, see example below.
 #+TEXT:        Several lines may be given.
 #+OPTIONS:     H:2 num:t toc:t \n:nil @@:t ::t |:t ^:t f:t TeX:t ...
 #+BIND:        lisp-var lisp-val, e.g.: org-export-latex-low-levels itemize
+               @r{You need to confirm using these, or configure @code{org-export-allow-BIND}}
 #+LINK_UP:     the ``up'' link of an exported page
 #+LINK_HOME:   the ``home'' link of an exported page
 #+LATEX_HEADER: extra line(s) for the LaTeX header, like \usepackage@{xyz@}

lisp/ChangeLog

@@ -1,6 +1,7 @@
 2009-08-05  Carsten Dominik  <carsten.dominik@gmail.com>
 
 	* org-exp.el (org-default-export-plist): Respect #+BIND.
+	(org-export-confirm-letbind): New function.
 
 	* org.el (org-paste-subtree): Test the kill ring entry if it is
 	going to be used.

lisp/org-exp.el

@@ -51,6 +51,16 @@
   :tag "Org Export General"
   :group 'org-export)
 
+(defcustom org-export-allow-BIND 'confirm
+  "Non-nil means, allow #+BIND to define local variable values for export.
+This is a potential security risk, which is why the user must confirm the
+use of these lines."
+  :group 'org-export-general
+  :type '(choice
+	  (const :tag "Never" nil)
+	  (const :tag "Always" t)
+	  (const :tag "Make the user confirm for each file" confirm)))
+
 ;; FIXME
 (defvar org-export-publishing-directory nil)
 
@@ -704,7 +714,8 @@ modified) list.")
 			    "\n" setup-contents "\n"
 			    (substring ext-setup-or-nil start)))))))
 	(setq p (plist-put p :text text))
-	(setq p (plist-put p :let-bind letbind))
+	(when (and letbind (org-export-confirm-letbind))
+	  (setq p (plist-put p :let-bind letbind)))
 	(when style (setq p (plist-put p :style-extra style)))
 	(when latex-header
 	  (setq p (plist-put p :latex-header-extra (substring latex-header 1))))
@@ -733,6 +744,18 @@ modified) list.")
 		     (match-string 2 val)))))
 	p))))
 
+(defvar org-export-allow-BIND-local nil)
+(defun org-export-confirm-letbind ()
+  "Can we use #+BIND values during export?"
+  (cond
+   ((not org-export-allow-BIND) nil)
+   ((eq org-export-allow-BIND t) t)
+   (t
+    (if (local-variable-p 'org-export-allow-BIND-local)
+	org-export-allow-BIND-local
+      (org-set-local 'org-export-allow-BIND-local
+		     (yes-or-no-p "Allow BIND values in this buffer? "))))))
+
 (defun org-install-letbind ()
   "Install the values from #+BIND lines as local variables."
   (let ((letbind (plist-get org-export-opt-plist :let-bind)))