Index: src/xdisp.c
===================================================================
RCS file: /sources/emacs/emacs/src/xdisp.c,v
retrieving revision 1.1140
diff -u -r1.1140 xdisp.c
--- src/xdisp.c	22 Feb 2007 11:23:11 -0000	1.1140
+++ src/xdisp.c	29 Mar 2007 13:11:29 -0000
@@ -17618,7 +17618,10 @@
    the exception being w->base_line_pos.  */
 
 static char lots_of_dashes[] = "--------------------------------------------------------------------------------------------------------------------------------------------";
-
+#define XDISP_PID
+#ifdef XDISP_PID
+static  char s[32];	/* %x special for pid	*/
+#endif
 static char *
 decode_mode_spec (w, c, field_width, precision, multibyte)
      struct window *w;
@@ -17630,7 +17633,9 @@
   struct frame *f = XFRAME (WINDOW_FRAME (w));
   char *decode_mode_spec_buf = f->decode_mode_spec_buffer;
   struct buffer *b = current_buffer;
-
+#ifdef XDISP_PID
+  int n;	/* %x special for pid	*/
+#endif
   obj = Qnil;
   *multibyte = 0;
 
@@ -17971,7 +17976,12 @@
 #else
       return "T";
 #endif
-
+#ifdef XDISP_PID
+    case 'x':
+      n = (unsigned int) getpid(); 
+      sprintf(s, "%d", n);
+      return s;
+#endif
     case 'z':
       /* coding-system (not including end-of-line format) */
     case 'Z':