time-date.el: Port new time stamp handling to old Emacs and to XEmacs

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b6dbedc..83f87d3 100644 (file)
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -5,13 +5,21 @@
 
 2014-11-17  Paul Eggert  <eggert@cs.ucla.edu>
 
+       Port new time stamp handling to old Emacs and to XEmacs.
+       This is needed for Gnus, which copies time-date.el and which
+       runs on older Emacs implementations.
+       * time-date.el (with-decoded-time-value):
+       Handle 'nil' and floating-point arg more compatibly with new Emacs.
+       (encode-time-value, with-decoded-time-value):
+       Obsolete only if new Emacs.
+       (time-add, time-subtract, time-less-p): Define if not new Emacs.
+
        Improve time stamp handling, and be more consistent about it.
        This implements a suggestion made in:
        http://lists.gnu.org/archive/html/emacs-devel/2014-10/msg00587.html
        Among other things, this means timer.el no longer needs to
        autoload the time-date module.
-       * time-date.el (seconds-to-time, days-to-time, time-since):
-       Simplify by using new functionality.
+       * time-date.el (seconds-to-time, days-to-time, time-since)
        (with-decoded-time-value):
        Treat 'nil' as current time.  This is mostly for XEmacs.
        (encode-time-value, with-decoded-time-value): Obsolete.

diff --git a/lisp/time-date.el b/lisp/time-date.el
index 100e856..a9c30f4 100644 (file)
--- a/lisp/time-date.el
+++ b/lisp/time-date.el
@@ -65,12 +65,36 @@ list (HIGH LOW MICRO PICO)."
                     (pop elt)))
             (time-value (car elt))
             (gensym (make-symbol "time")))
-       `(let* ,(append `((,gensym ,time-value)
+       `(let* ,(append `((,gensym (or ,time-value (current-time)))
+                         (,gensym
+                          (cond
+                           ((integerp ,gensym)
+                            (list (ash ,gensym -16)
+                                  (logand ,gensym 65535)))
+                           ((floatp ,gensym)
+                            (let* ((usec (* 1000000 (mod ,gensym 1)))
+                                   (ps (round (* 1000000 (mod usec 1))))
+                                   (us (floor usec))
+                                   (lo (floor (mod ,gensym 65536)))
+                                   (hi (floor ,gensym 65536)))
+                              (if (eq ps 1000000)
+                                  (progn
+                                    (setq ps 0)
+                                    (setq us (1+ us))
+                                    (if (eq us 1000000)
+                                        (progn
+                                          (setq us 0)
+                                          (setq lo (1+ lo))
+                                          (if (eq lo 65536)
+                                              (progn
+                                                (setq lo 0)
+                                                (setq hi (1+ hi))))))))
+                              (list hi lo us ps)))
+                           (t ,gensym)))
                          (,high (pop ,gensym))
                          ,low ,micro)
                        (when pico `(,pico))
                        (when type `(,type)))
-          (or ,gensym (setq ,gensym (current-time)))
           (if (consp ,gensym)
               (progn
                 (setq ,low (pop ,gensym))
@@ -108,7 +132,7 @@ it is assumed that PICO was omitted and should be treated as zero."
    ((eq type 3) (list high low micro pico))
    ((null type) (encode-time-value high low micro 0 pico))))
 
-(when (featurep 'emacs)
+(when (and (fboundp 'time-add) (subrp (symbol-function 'time-add)))
   (make-obsolete 'encode-time-value nil "25.1")
   (make-obsolete 'with-decoded-time-value nil "25.1"))
 
@@ -192,7 +216,7 @@ TIME should be either a time value or a date-time string."
 ;;;###autoload(autoload 'time-less-p "time-date")
 
 (eval-when-compile
-  (when (not (featurep 'emacs))
+  (when (not (and (fboundp 'time-add) (subrp (symbol-function 'time-add))))
 
     (defun time-add (t1 t2)
       "Add two time values T1 and T2.  One should represent a time difference."