Re: [PATCH] org-macs.el: Do not compare wall time and file modification time

[Paul Eggert]

The comments don't seem to match the code here.

> +  (let* ((tangled-file (concat (file-name-sans-extension file) ".el"))
> +         (file-mtime (file-attribute-modification-time
> +                      (file-attributes (file-truename file))))
> +         (tangled-mtime (file-attribute-modification-time
> +                         (file-attributes (file-truename tangled-file)))))
> +    ;; Tangle only if the Elisp file is older than the Org file.
> +    ;; Filesystem may have coarse timestamp resolution (HFS+, FAT)
> +    ;; so no need to update if timestamps are equal and thus
> +    ;; `org-file-newer-than-p' can not be used here.
> +    (unless (and file-mtime
> +                 tangled-mtime
> +                 (not (time-less-p tangled-mtime file-mtime)))

Although this looks correct, there's no need to go to the work of 
computing file-mtime in the common case where tangled-mtime is nil.