(help-xref-on-pp): Only add xref if the text is less than 5K.

1 files changed, 23 insertions, 25 deletions

diff --git a/lisp/help-mode.el b/lisp/help-mode.el
index 904d08f7519..03a711115db 100644
--- a/lisp/help-mode.el
+++ b/lisp/help-mode.el
@@ -443,31 +443,29 @@ See `help-make-xrefs'."
 ;;;###autoload
 (defun help-xref-on-pp (from to)
   "Add xrefs for symbols in `pp's output between FROM and TO."
-  (let ((ost (syntax-table)))
-    (unwind-protect
-        (save-excursion
-          (save-restriction
-            (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))
-                   ((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))))
+  (if (> (- to from) 5000) nil
+    (with-syntax-table emacs-lisp-mode-syntax-table
+      (save-excursion
+        (save-restriction
+          (narrow-to-region from to)
+          (goto-char (point-min))
+          (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)))))))
 
 
 ;; Additional functions for (re-)creating types of help buffers.