Mark overly long lines.

init.el

@@ -1,5 +1,5 @@
 ;;; init.el --- tastytea's Emacs init file.
-;; Time-stamp: <2019-07-24T05:11:03+00:00>
+;; Time-stamp: <2019-07-27T06:30:53+00:00>
 
 ;;; Commentary:
 ;; I am using this file with Emacs 26, but most of it will probably work with
@@ -560,7 +560,7 @@ With argument, do this that many times."
   :after company
   :config
   (delete 'newline-mark whitespace-style) ; Don't paint $ at eol.
-  (delete 'lines whitespace-style)        ; Don't paint lines red if too long.
+  ;; (delete 'lines whitespace-style)        ; Don't mark overly long lines.
   ;; Workaround to not show dots in popup menus.
   (defun my/whitespace-mode-enabled-p ()
     (symbol-value 'whitespace-mode))
@@ -593,7 +593,15 @@ With argument, do this that many times."
   (conf-mode . whitespace-mode)
   (text-mode . whitespace-mode)
   :custom-face
-  (whitespace-space ((nil :foreground "gray18"))))
+  (whitespace-space ((nil :foreground "gray18")))
+  (whitespace-line ((nil :inherit whitespace-line
+                         :weight normal
+                         :foreground nil
+                         :background nil
+                         :distant-foreground "red" ; Make dots red.
+                         ;; :box (:line-width 1 :color "dark red")
+                         )))
+  )
 
 ;; Spell checking.
 (unless slow-computer