Re: [Bug-AUCTeX] 11.86; pngs not being generated by preview-latex

[Ralf Angeli]

* Clark Taylor (2010-10-13) writes:

> Your patch solved the problem.  It works with gs9.00 and your patch.

Thanks for testing.  Also to Stefan.

Below you can find a patch which should solve the problem without
introducing a security issue.  At least I hope.  It would be nice if
somebody with some knowledge of Ghostscript could review it.

The idea is that while Ghostscript is started with -dDELAYSAFER, SAFER
mode is enabled as soon as reading is permitted for the required files.
This is done with .locksafe.  The .setsafe statement in the original
value of `preview-gs-init-string' should not be executed after that, so
the the PermitFile... parameters should not be reset to empty arrays.  I
kept the .setsafe for the case without fast conversion.  (All this is
done after gs is started.  An alternative would be to do a `-dDELAYSAFER
-c '<</PermitFileReading...' -dSAFER'.  But this clashes a bit with the
custmizability of the `preview-gs-options'.)

A propos fast conversion, I'm not sure yet if it is enough to set the
file permissions in `preview-prepare-fast-conversion' or if this has to
be done earlier, .e.g in `preview-gs-open'.


--- preview.el  18 Jun 2009 19:20:46 -0000      1.284
+++ preview.el  13 Oct 2010 16:28:42 -0000
@@ -355,7 +355,7 @@
   :group 'preview-gs
   :type 'string)
 
-(defcustom preview-gs-options '("-q" "-dSAFER" "-dNOPAUSE"
+(defcustom preview-gs-options '("-q" "-dDELAYSAFER" "-dNOPAUSE"
                                "-DNOPLATFONTS" "-dPrinted"
                                "-dTextAlphaBits=4"
                                "-dGraphicsAlphaBits=4")
@@ -1066,14 +1066,21 @@
 
 (defun preview-prepare-fast-conversion ()
   "This fixes up all parameters for fast conversion."
-  (let ((file (if (consp (car preview-ps-file))
-                 (if (consp (caar preview-ps-file))
-                     (car (last (caar preview-ps-file)))
-                   (caar preview-ps-file))
-               (car preview-ps-file))))
+  (let* ((file (if (consp (car preview-ps-file))
+                  (if (consp (caar preview-ps-file))
+                      (car (last (caar preview-ps-file)))
+                    (caar preview-ps-file))
+                (car preview-ps-file)))
+        (all-files (if (and (consp (car preview-ps-file))
+                            (consp (caar preview-ps-file)))
+                       (caar preview-ps-file)
+                     (list file))))
     (setq preview-gs-dsc (preview-dsc-parse file))
     (setq preview-gs-init-string
-         (concat preview-gs-init-string
+         (concat (format "{<</PermitFileReading[%s]>> setuserparams \
+.locksafe} stopped pop "
+                         (mapconcat 'preview-ps-quote-filename all-files ""))
+                 preview-gs-init-string
                  (format "[%s(r)file]aload exch %s .runandhide aload pop "
                          (preview-ps-quote-filename file)
                          (preview-gs-dsc-cvx 0 preview-gs-dsc))))))


-- 
Ralf