Remove background colors from shr

emacs/.emacs.d/init.org

@@ -456,6 +456,14 @@ To start off, first I need to enable lexical binding.
     (add-hook 'minibuffer-setup-hook 'electric-pair-local-mode)
   #+END_SRC
 
+* Libraries
+
+  - [[file:init/oni-shr-init.org][shr]]
+
+    #+BEGIN_SRC emacs-lisp
+      (with-eval-after-load 'shr (load "oni-shr-init"))
+    #+END_SRC
+
 * Minor modes
 
   - [[file:init/oni-company-init.org][Company mode]] :: A better auto completion system than auto

emacs/.emacs.d/init/oni-shr-init.org

@@ -0,0 +1,28 @@
+#+TITLE: shr configuration
+
+#+BEGIN_SRC emacs-lisp
+  (require 'shr)
+#+END_SRC
+
+* Remove background colors
+
+  Define a procedure that removes the last argument it gets if there
+  are more than 3.
+
+  #+BEGIN_SRC emacs-lisp
+    (defun oni:shr-colorize-remove-last-arg (args)
+      "If ARGS has more than 3 items, remove the last one."
+      (if (> (length args) 3)
+          (butlast args)
+        args))
+  #+END_SRC
+
+  Add the function as a filter-args advice to
+  =shr-colorize-region=. The last (fourth) argument to that function
+  is the background color to use, it's optional, so removing it
+  effectively stops shr from adding background colors.
+
+  #+BEGIN_SRC emacs-lisp
+    (advice-add #'shr-colorize-region :filter-args
+                #'oni:shr-colorize-remove-last-arg)
+  #+END_SRC