(help-xref-on-pp): Catch and ignore errors in scanning the buffer.

lisp/ChangeLog

 2001-12-25  Richard M. Stallman  <rms@gnu.org>
+	* help-mode.el (help-xref-on-pp): Catch and ignore errors in scanning
+	the buffer.
+
 	* startup.el (command-line): Convert command line args
 	to Emacs internal representation using locale-coding-system.

lisp/help-mode.el

@@ -463,6 +463,7 @@ See `help-make-xrefs'."
 	    (set-syntax-table emacs-lisp-mode-syntax-table)
 	    (narrow-to-region from to)
 	    (goto-char (point-min))
+	    (condition-case nil
 		(while (not (eobp))
 		  (cond
 		   ((looking-at "\"") (forward-sexp 1))
@@ -477,7 +478,8 @@ See `help-make-xrefs'."
 					'help-variable))))
 		      (when type (help-xref-button 1 type sym)))
 		    (goto-char (match-end 1)))
-	       (t (forward-char 1))))))
+		   (t (forward-char 1))))
+	      (error nil))))
       (set-syntax-table ost))))