fix whitespace and undo-tree

- Remove whitespace, except on diff-mode
- Improve syntax undo-tree-mode

lisp/init-editing-utils.el

@@ -1,6 +1,14 @@
-;; Delete trailing whitespace before saving fil
+;;----------------------------------------------------------------------------
-(add-hook 'before-save-hook 'delete-trailing-whitespace)
+;; Remove whitespaces
+;;----------------------------------------------------------------------------
+;; Delete trailing whitespace before saving fil → all modes
+;; (add-hook 'before-save-hook 'delete-trailing-whitespace)
 
+;; Delete-trailing-whitespace-when-saving-except-certain-modes
+(add-hook 'before-save-hook
+          (when '(not diff-mode))
+             'delete-trailing-whitespace)
+;;----------------------------------------------------------------------------
 ;; Automatic pairs open symbols (, {, [...
 ;; Disable for default.
 ;; Uncomment the next 4 lines if you want to enable the pairs-mode
@@ -35,8 +43,13 @@
 ;;----------------------------------------------------------------------------
 ;; Undo-tree
 ;;----------------------------------------------------------------------------
-(use-package undo-tree)
+(use-package undo-tree
-(global-undo-tree-mode)
+  :diminish undo-tree-mode
+  :config
+  (progn
+    (global-undo-tree-mode)
+    (setq undo-tree-visualizer-timestamps nil)
+    (setq undo-tree-visualizer-diff nil)))
 
 ;;----------------------------------------------------------------------------
 (myemacs/elapsed-time)