diff --git a/tex.el b/tex.el
index b85a72a..6e1f977 100644
--- a/tex.el
+++ b/tex.el
@@ -2513,6 +2513,16 @@ Return nil otherwise."
     (search-backward "\n\^L" (max (- (point-max) 3000) (point-min)) 'move)
     (re-search-forward "^%+ *TeX-master:" nil t)))
 
+(defun TeX-add-document-variables (&rest sym-val)
+  "Set first element of SYM-VAL to the next one, and so on.
+
+The variables are set if current file is not the master.  This is
+used to store variables shared among the whole document into the
+auto-saved file."
+  (unless (equal TeX-master t)
+    (while var-val
+      (set (pop sym-val) (pop sym-val)))))
+
 ;;; Style Paths
 
 (defcustom TeX-style-global (expand-file-name "style" TeX-data-directory)
@@ -3988,22 +3998,39 @@ If TEX is a directory, generate style files for all files in the directory."
 			    LaTeX-provided-class-options))
 	    (pkg-opts (if (boundp 'LaTeX-provided-package-options)
 			  LaTeX-provided-package-options))
-	    (tex-cmd-opts TeX-command-extra-options)
 	    (verb-envs (when (boundp 'LaTeX-verbatim-environments-local)
 			 LaTeX-verbatim-environments-local))
 	    (verb-macros-delims (when (boundp 'LaTeX-verbatim-macros-with-delims-local)
 				  LaTeX-verbatim-macros-with-delims-local))
 	    (verb-macros-braces (when (boundp 'LaTeX-verbatim-macros-with-braces-local)
 				  LaTeX-verbatim-macros-with-braces-local))
-	    (dialect TeX-style-hook-dialect))
+	    (dialect TeX-style-hook-dialect)
+	    (master (equal TeX-master t))
+	    shared-variables)
+	;; If we are parsing master file, retrieve variables to be shared among
+	;; the whole document.
+	(when master
+	  ;; (hack-local-variables) ;; <= !!!!!
+	  (dolist (var '(TeX-engine TeX-PDF-mode TeX-command-extra-options
+				    TeX-PDF-from-DVI ConTeXt-Mark-version))
+	    ;; Add the variable only if it has a local binding.
+	    (when (local-variable-p var)
+	      (push (cons var (symbol-value var)) shared-variables))))
 	(TeX-unload-style style)
 	(with-current-buffer (generate-new-buffer file)
 	  (erase-buffer)
 	  (insert "(TeX-add-style-hook\n \""
 		  style "\"\n (lambda ()")
-	  (unless (string= tex-cmd-opts "")
-	    (insert "\n   (setq TeX-command-extra-options\n"
-		    "         " (prin1-to-string tex-cmd-opts) ")"))
+	  (and
+	   ;; Save only if current file is the master.
+	   master
+	   shared-variables
+	   (insert "\n   (TeX-add-document-variables"
+		   (mapconcat (lambda (sym-val)
+				(concat "\n    '" (prin1-to-string (car sym-val))
+					"\n    " (prin1-to-string (cdr sym-val))))
+			      shared-variables "")
+		   ")"))
 	  (when class-opts
 	    (insert "\n   (TeX-add-to-alist 'LaTeX-provided-class-options\n"
 		    "                     '" (prin1-to-string class-opts) ")"))