(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

@@ -463,21 +463,23 @@ See `help-make-xrefs'."
 	    (set-syntax-table emacs-lisp-mode-syntax-table)
 	    (narrow-to-region from to)
 	    (goto-char (point-min))
-	    (while (not (eobp))
-	      (cond
-	       ((looking-at "\"") (forward-sexp 1))
-	       ((looking-at "#<") (search-forward ">" nil 'move))
-	       ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)")
-		(let* ((sym (intern-soft (match-string 1)))
-		       (type (cond ((fboundp sym) 'help-function)
-				 ((or (memq sym '(t nil))
-				      (keywordp sym))
-				  nil)
-				 ((and sym (boundp sym))
-				  'help-variable))))
-		  (when type (help-xref-button 1 type sym)))
-		(goto-char (match-end 1)))
-	       (t (forward-char 1))))))
+	    (condition-case nil
+		(while (not (eobp))
+		  (cond
+		   ((looking-at "\"") (forward-sexp 1))
+		   ((looking-at "#<") (search-forward ">" nil 'move))
+		   ((looking-at "\\(\\(\\sw\\|\\s_\\)+\\)")
+		    (let* ((sym (intern-soft (match-string 1)))
+			   (type (cond ((fboundp sym) 'help-function)
+				       ((or (memq sym '(t nil))
+					    (keywordp sym))
+					nil)
+				       ((and sym (boundp sym))
+					'help-variable))))
+		      (when type (help-xref-button 1 type sym)))
+		    (goto-char (match-end 1)))
+		   (t (forward-char 1))))
+	      (error nil))))
       (set-syntax-table ost))))