Don't want the first line of a git commit COMMIT_EDITMSG buffer in Emacs to wrap?

git-commit-fill-nobreak-predicate.el

(defun tkb-magit-commit-fill-nobreak-p ()
  "Don't fill on the first line of a magit commit message."
  (= 1 (line-number-at-pos)))

(defun tkb-magit-commit-find-file-hook ()
  (interactive)
  (when (string-match "COMMIT_EDITMSG\\'" (buffer-file-name))
    (make-local-variable 'fill-nobreak-predicate)
    (add-to-list 'fill-nobreak-predicate #'tkb-magit-commit-fill-nobreak-p)))
;; Using add-to-list without specifying APPEND didn't work because
;; that added it to the front of the list and the
;; git-commit-setup-check-buffer find file hook ran later. The
;; git-commit-setup-check-buffer runs git-commit-setup which runs
;; normal-mode which runs kill-all-local-variables, which wiped out
;; what tkb-magit-commit-find-file-hook was trying to do.
(add-to-list 'find-file-hook #'tkb-magit-commit-find-file-hook t)