[nongnu] elpa/goto-chg 4eee444 23/27: goto-last-change: don't check buffer-undo-tree when not using undo-tree

[Philip Kaludercic]

branch: elpa/goto-chg
commit 4eee44444cd39cfa9b6cb8053f863581f98d46e3
Author: Brian Leung <leungbk@mailfence.com>
Commit: Brian Leung <leungbk@mailfence.com>

    goto-last-change: don't check buffer-undo-tree when not using undo-tree
    
    People who don't have undo-tree loaded will receive a void-variable
    error if they call `goto-last-change' in a file that hasn't been
    changed.
---
 goto-chg.el | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/goto-chg.el b/goto-chg.el
index 31cf016..4aa6003 100644
--- a/goto-chg.el
+++ b/goto-chg.el
@@ -97,6 +97,8 @@
 
 ;;; Code:
 
+(require 'undo-tree nil t)
+
 (defvar glc-default-span 8 "*goto-last-change don't visit the same point 
twice. glc-default-span tells how far around a visited point not to visit 
again.")
 (defvar glc-current-span 8 "Internal for goto-last-change.\nA copy of 
glc-default-span or the ARG passed to goto-last-change.")
 (defvar glc-probe-depth 0 "Internal for goto-last-change.\nIt is non-zero 
between successive goto-last-change.")
@@ -268,7 +270,9 @@ discarded. See variable `undo-limit'."
                glc-current-span glc-default-span)
          (if (< (prefix-numeric-value arg) 0)
              (error "Negative arg: Cannot reverse as the first operation"))))
-  (cond ((and (null buffer-undo-list) (null buffer-undo-tree))
+  (cond ((and (null buffer-undo-list)
+              (or (not (boundp 'buffer-undo-tree))
+                  (null buffer-undo-tree)))
          (error "Buffer has not been changed"))
         ((eq buffer-undo-list t)
          (error "No change info (undo is disabled)")))