Ange-FTP. Suggested by Kai Grossjohann.
"Return non-nil if FILE has not changed since the last checkout."
(let ((checkout-time (vc-file-getprop file 'vc-checkout-time))
(lastmod (nth 5 (file-attributes file))))
- (if checkout-time
+ (if (and checkout-time
+ ;; Tramp and Ange-FTP return this when they don't know the time.
+ (not (equal lastmod '(0 0))))
(equal checkout-time lastmod)
(let ((unchanged (vc-call workfile-unchanged-p file)))
(vc-file-setprop file 'vc-checkout-time (if unchanged lastmod 0))