(forms-mode): Plug security hole by disabling `eval-buffer' unless

`enable-local-eval' is set to t.
Correct setting of `forms--mode-setup'.
(forms--local-write-file-function): New function to be used as
`local-write-file-hooks'.
(forms-mode): Use it.
(forms-find-file,forms-find-file-other-window): Locally set
`enable-local-eval' and `enable-local-variables' to t.
(forms-find-file-other-window): Remove extraneous call to
`eval-current-buffer'.

1 files changed, 36 insertions, 24 deletions

diff --git a/lisp/forms.el b/lisp/forms.el
index 083eb1cb53f..9418f2f2341 100644
--- a/lisp/forms.el
+++ b/lisp/forms.el
@@ -2,7 +2,7 @@
 ;;; Copyright (C) 1991, 1993 Free Software Foundation, Inc.
 
 ;; Author: Johan Vromans <jv@nl.net>
-;; Version: $Revision: 2.5 $
+;; Version: $Revision: 2.6 $
 
 ;; This file is part of GNU Emacs.
 
@@ -266,10 +266,10 @@
 (provide 'forms)                        ;;; official
 (provide 'forms-mode)                   ;;; for compatibility
 
-(defconst forms-version (substring "$Revision: 2.5 $" 11 -2)
+(defconst forms-version (substring "$Revision: 2.6 $" 11 -2)
   "The version number of forms-mode (as string).  The complete RCS id is:
 
-  $Id: forms.el,v 2.5 1994/05/07 01:52:42 kwzh Exp rms $")
+  $Id: forms.el,v 2.6 1994/05/22 22:07:37 rms Exp rms $")
 
 (defvar forms-mode-hooks nil
   "Hook functions to be run upon entering Forms mode.")
@@ -444,7 +444,13 @@ Commands:                        Equivalent keys in read-only mode:
 
         ;; eval the buffer, should set variables
         ;;(message "forms: processing control file...")
-        (eval-current-buffer)
+        ;; If enable-local-eval is not set to t the user is asked first.
+        (if (or (eq enable-local-eval t)
+                (yes-or-no-p 
+                 (concat "Evaluate lisp code in buffer "
+                         (buffer-name) " to display forms ")))
+            (eval-current-buffer)
+          (error "`enable-local-eval' inhibits buffer evaluation"))
 
         ;; check if the mandatory variables make sense.
         (or forms-file
@@ -514,6 +520,9 @@ Commands:                        Equivalent keys in read-only mode:
         ;;(message "forms: setting up... done.")
         ))
 
+  ;; initialization done
+  (setq forms--mode-setup t)
+
   ;; Copy desired faces to the actual variables used by the forms formatter.
   (if (fboundp 'make-face)
       (progn
@@ -595,9 +604,7 @@ Commands:                        Equivalent keys in read-only mode:
 
   ;; be helpful
   (forms--help)
-
-  ;; initialization done
-  (setq forms--mode-setup t))
+)
 
 (defun forms--process-format-list ()
   ;; Validate `forms-format-list' and set some global variables.
@@ -1163,19 +1170,13 @@ Commands:                        Equivalent keys in read-only mode:
                                    (current-local-map)
                                    (current-global-map))))
   ;;
-  ;; save-buffer -> forms--save-buffer
+  ;; Use local-write-file-hooks to invoke our own buffer save
+  ;; function. Note however that it usually does not work.
   (make-local-variable 'local-write-file-hooks)
-  (add-hook 'local-write-file-hooks
-            (function
-             (lambda (nil)
-               (forms--checkmod)
-               (save-excursion
-                 (set-buffer forms--file-buffer)
-                 (save-buffer))
-               t)))
-  ;; We have our own revert function - use it
+  (add-hook 'local-write-file-hooks 'forms--local-write-file-function)
+  ;; We have our own revert function - use it.
   (make-local-variable 'revert-buffer-function)
-  (setq revert-buffer-function 'forms-revert-buffer)
+  (setq revert-buffer-function 'forms--revert-buffer)
 
   t)
 
@@ -1366,16 +1367,19 @@ As a side effect: sets `forms--the-record-list'."
 (defun forms-find-file (fn)
   "Visit a file in Forms mode."
   (interactive "fForms file: ")
-  (find-file-read-only fn)
-  (or forms--mode-setup (forms-mode t)))
+  (let ((enable-local-eval t)
+        (enable-local-variables t))
+    (find-file-read-only fn)
+    (or forms--mode-setup (forms-mode t))))
 
 ;;;###autoload
 (defun forms-find-file-other-window (fn)
   "Visit a file in Forms mode in other window."
   (interactive "fFbrowse file in other window: ")
-  (find-file-other-window fn)
-  (eval-current-buffer)
-  (or forms--mode-setup (forms-mode t)))
+  (let ((enable-local-eval t)
+        (enable-local-variables t))
+    (find-file-other-window fn)
+    (or forms--mode-setup (forms-mode t))))
 
 (defun forms-exit (query)
   "Normal exit from Forms mode.  Modified buffers are saved."
@@ -1608,7 +1612,15 @@ it is called to fill (some of) the fields with default values."
           (re-search-forward regexp nil t))))
   (setq forms--search-regexp regexp))
 
-(defun forms-revert-buffer (&optional arg noconfirm)
+(defun forms--local-write-file-function ()
+  "Local write file hook."
+  (forms--checkmod)
+  (save-excursion
+    (set-buffer forms--file-buffer)
+    (save-buffer))
+  t)
+
+(defun forms--revert-buffer (&optional arg noconfirm)
   "Reverts current form to un-modified."
   (interactive "P")
   (if (or noconfirm