Subject: Re: bug#5984: Crash displaying composed characters

From: Andreas Schwab <[email-masked]>
Date: Wed, 21 Apr 2010 14:33:59 +0200

Juanma Barranquero <[email-masked]> writes:

>> Please try this patch.
>
> With it, I don't get a crash, but an error:
>
>   Wrong type argument: bufferp, 12846208

Here's an updated patch.

Andreas.

=== modified file 'src/composite.c'
--- src/composite.c	2010-01-14 03:54:04 +0000
+++ src/composite.c	2010-04-21 12:10:13 +0000
@@ -986,20 +986,31 @@ autocmp_chars (cft_element, charpos, byt
 	    font_object = win->frame;
 	  gstring = Fcomposition_get_gstring (pos, make_number (to),
 					      font_object, string);
-	  if (NILP (LGSTRING_ID (gstring)))
+	  if (!NILP (LGSTRING_ID (gstring)))
 	    {
-	      Lisp_Object args[6];
-
-	      args[0] = Vauto_composition_function;
-	      args[1] = AREF (elt, 2);
-	      args[2] = pos;
-	      args[3] = make_number (to);
-	      args[4] = font_object;
-	      args[5] = string;
-	      gstring = safe_call (6, args);
+	      if (NILP (string))
+		TEMP_SET_PT_BOTH (pt, pt_byte);
+	      return unbind_to (count, gstring);
 	    }
+
+	  /* Save point as marker before calling out to lisp.  */
 	  if (NILP (string))
-	    TEMP_SET_PT_BOTH (pt, pt_byte);
+	    {
+	      Lisp_Object m = Fmake_marker ();
+	      set_marker_both (m, Qnil, pt, pt_byte);
+	      record_unwind_protect (restore_point_unwind, m);
+	    }
+	  {
+	    Lisp_Object args[6];
+
+	    args[0] = Vauto_composition_function;
+	    args[1] = AREF (elt, 2);
+	    args[2] = pos;
+	    args[3] = make_number (to);
+	    args[4] = font_object;
+	    args[5] = string;
+	    gstring = safe_call (6, args);
+	  }
 	  return unbind_to (count, gstring);
 	}
     }

=== modified file 'src/fileio.c'
--- src/fileio.c	2010-04-21 03:02:58 +0000
+++ src/fileio.c	2010-04-21 09:22:01 +0000
@@ -299,7 +299,7 @@ close_file_unwind (fd)
 
 /* Restore point, having saved it as a marker.  */
 
-static Lisp_Object
+Lisp_Object
 restore_point_unwind (location)
      Lisp_Object location;
 {

=== modified file 'src/lisp.h'
--- src/lisp.h	2010-04-21 03:02:58 +0000
+++ src/lisp.h	2010-04-21 09:22:01 +0000
@@ -3061,6 +3061,7 @@ EXFUN (Ffile_readable_p, 1);
 EXFUN (Ffile_executable_p, 1);
 EXFUN (Fread_file_name, 6);
 extern Lisp_Object close_file_unwind P_ ((Lisp_Object));
+extern Lisp_Object restore_point_unwind P_ ((Lisp_Object));
 extern void report_file_error P_ ((const char *, Lisp_Object)) NO_RETURN;
 extern int internal_delete_file P_ ((Lisp_Object));
 extern void syms_of_fileio P_ ((void));

-- 
Andreas Schwab, [email-masked]
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."