How to make C-g cancel evil-replace rather than typing ^G?

Question

In evil mode, the r command, evil-replace, waits for a replacement character to be typed and replaces the current character with it. Sometimes I hit r by mistake and wish to cancel, so I hit C-g. Instead of cancelling the evil-replace, however, it replaces the current character with the escape code ^G which I then have to undo.

Is there a way to make C-g cancel the evil-replace, like esc does?

Update: this is now built in to evil. See https://github.com/emacs-evil/evil/pull/1111. The answers below now only apply to legacy evil versions.

Answer 1

I was able to accomplish this using advice (I know that's not ideal, and I'm new to advice, so the code that follows probably isn't great)

(defun replace-control-g-with-nil (char)
  "Make C-g read as nil so that `r C-g` cancels the replace."
  (let ((control-g-char ?\a))
    (if (eq char control-g-char)
        (progn
          (message "Quit")  ; Without calling message, the cursor stays looking like replace
          nil)              ; Returning nil cancels the evil-replace
      char)))

(advice-add 'evil-read-key :filter-return 'replace-control-g-with-nil)

Answer 2

Sure. If you inspect evil-replace-state-map with F1 v, you'll notice it has ESC bound to evil-normal-state. You can do the same for C-g as well:

(eval-after-load 'evil-maps
  '(define-key evil-replace-state-map (kbd "C-g") 'evil-normal-state))