Remove some assumptions about timestamp format

These changes remove some assumptions of Lisp code on timestamp
format.  Although we’re not going to change the default format any
time soon, I went looking for code that was too intimate about
details of timestamp format and removed assumptions where this was
easy to do with current Emacs primitives.
* lisp/ido.el (ido-wash-history):
Fix test for zero timestamp.
* lisp/time.el (display-time-event-handler):
Use time-less-p rather than doing it by hand.
(display-time-update): Simplify by using float-time
instead of doing the equivalent by hand.
* lisp/url/url-auth.el (url-digest-auth-make-cnonce):
* test/lisp/calendar/parse-time-tests.el (parse-time-tests):
* test/lisp/emacs-lisp/timer-tests.el (timer-test-multiple-of-time):
* test/lisp/net/tramp-tests.el:
(tramp-test19-directory-files-and-attributes)
(tramp-test22-file-times, tramp-test23-visited-file-modtime):
Don’t assume detailed format of returned Lisp timestamps.

3 files changed, 43 insertions, 27 deletions

diff --git a/test/lisp/calendar/parse-time-tests.el b/test/lisp/calendar/parse-time-tests.el
index 9689997f793..ca71ff71b7a 100644
--- a/test/lisp/calendar/parse-time-tests.el
+++ b/test/lisp/calendar/parse-time-tests.el
@@ -45,20 +45,34 @@
                  '(42 35 19 22 2 2016 1 nil -28800)))
   (should (equal (parse-time-string "Friday, 21 Sep 2018 13:47:58 PDT")
                  '(58 47 13 21 9 2018 5 t -25200)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54-0200")
-                 '(13818 33666)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54-0230")
-                 '(13818 35466)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54-02:00")
-                 '(13818 33666)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54-02")
-                 '(13818 33666)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54+0230")
-                 '(13818 17466)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54+02")
-                 '(13818 19266)))
-  (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54Z")
-                 '(13818 26466)))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54-0200") t)
+		 "1998-09-12 14:21:54"))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54-0230") t)
+		 "1998-09-12 14:51:54"))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54-02:00") t)
+		 "1998-09-12 14:21:54"))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54-02") t)
+		 "1998-09-12 14:21:54"))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54+0230") t)
+		 "1998-09-12 09:51:54"))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54+02") t)
+		 "1998-09-12 10:21:54"))
+  (should (equal (format-time-string
+		  "%Y-%m-%d %H:%M:%S"
+		  (parse-iso8601-time-string "1998-09-12T12:21:54Z") t)
+		 "1998-09-12 12:21:54"))
   (should (equal (parse-iso8601-time-string "1998-09-12T12:21:54")
                  (encode-time 54 21 12 12 9 1998))))
 
diff --git a/test/lisp/emacs-lisp/timer-tests.el b/test/lisp/emacs-lisp/timer-tests.el
index fa92c1b64aa..1d3ba757f63 100644
--- a/test/lisp/emacs-lisp/timer-tests.el
+++ b/test/lisp/emacs-lisp/timer-tests.el
@@ -40,8 +40,10 @@
       (should (debug-timer-check)) t))
 
 (ert-deftest timer-test-multiple-of-time ()
-  (should (equal
-           (timer-next-integral-multiple-of-time '(0 0 0 1) (1+ (ash 1 53)))
-           (list (ash 1 (- 53 16)) 1 0 0))))
+  (should (zerop
+	   (float-time
+	    (time-subtract
+	     (timer-next-integral-multiple-of-time '(0 0 0 1) (1+ (ash 1 53)))
+	     (list (ash 1 (- 53 16)) 1))))))
 
 ;;; timer-tests.el ends here
diff --git a/test/lisp/net/tramp-tests.el b/test/lisp/net/tramp-tests.el
index 55884f30a7e..79013558fdb 100644
--- a/test/lisp/net/tramp-tests.el
+++ b/test/lisp/net/tramp-tests.el
@@ -2882,16 +2882,16 @@ This tests also `file-readable-p', `file-regular-p' and
 	    ;; able to return the date correctly.  They say "don't know".
 	    (dolist (elt attr)
 	      (unless
-		  (equal
-		   (nth
-		    5 (file-attributes (expand-file-name (car elt) tmp-name2)))
-		   '(0 0))
+		  (zerop
+		   (float-time
+		    (nth 5 (file-attributes
+			    (expand-file-name (car elt) tmp-name2)))))
 		(should
 		 (equal (file-attributes (expand-file-name (car elt) tmp-name2))
 			(cdr elt)))))
 	    (setq attr (directory-files-and-attributes tmp-name2 'full))
 	    (dolist (elt attr)
-	      (unless (equal (nth 5 (file-attributes (car elt))) '(0 0))
+	      (unless (zerop (float-time (nth 5 (file-attributes (car elt)))))
 		(should
 		 (equal (file-attributes (car elt)) (cdr elt)))))
 	    (setq attr (directory-files-and-attributes tmp-name2 nil "^b"))
@@ -3215,14 +3215,14 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
 	    (write-region "foo" nil tmp-name1)
 	    (should (file-exists-p tmp-name1))
 	    (should (consp (nth 5 (file-attributes tmp-name1))))
-	    ;; '(0 0) means don't know, and will be replaced by
-	    ;; `current-time'.  Therefore, we use '(0 1).  We skip the
+	    ;; A zero timestamp means don't know, and will be replaced by
+	    ;; `current-time'.  Therefore, use timestamp 1.  Skip the
 	    ;; test, if the remote handler is not able to set the
 	    ;; correct time.
 	    (skip-unless (set-file-times tmp-name1 (seconds-to-time 1)))
 	    ;; Dumb remote shells without perl(1) or stat(1) are not
 	    ;; able to return the date correctly.  They say "don't know".
-	    (unless (equal (nth 5 (file-attributes tmp-name1)) '(0 0))
+	    (unless (zerop (float-time (nth 5 (file-attributes tmp-name1))))
 	      (should
 	       (equal (nth 5 (file-attributes tmp-name1)) (seconds-to-time 1)))
 	      (write-region "bla" nil tmp-name2)
@@ -3250,9 +3250,9 @@ This tests also `make-symbolic-link', `file-truename' and `add-name-to-file'."
 	    (with-temp-buffer
 	      (insert-file-contents tmp-name)
 	      (should (verify-visited-file-modtime))
-	      (set-visited-file-modtime '(0 1))
+              (set-visited-file-modtime (seconds-to-time 1))
 	      (should (verify-visited-file-modtime))
-	      (should (equal (visited-file-modtime) '(0 1 0 0)))))
+	      (should (= 1 (float-time (visited-file-modtime))))))
 
 	;; Cleanup.
 	(ignore-errors (delete-file tmp-name))))))