master ba331c27f14: Port some timestamp tests to 32-bit time_t

branch: master
commit ba331c27f14adb429ef21fdf3d5c62febb7564d3
Author: Paul Eggert <[email protected]>
Commit: Paul Eggert <[email protected]>

    Port some timestamp tests to 32-bit time_t
    
    * test/lisp/calendar/icalendar-recur-tests.el:
    (ict:recur-tz-observance-on):
    * test/lisp/gnus/gnus-icalendar-tests.el (gnus-icalendary-byday):
    Skip these tests, which use timestamps before 1970, if the
    platform does not support that, e.g., unsigned 32-bit time_t,
    or signed 32-bit time_t for timestamps before 1901.
---
 test/lisp/calendar/icalendar-recur-tests.el | 3 ++-
 test/lisp/gnus/gnus-icalendar-tests.el      | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/test/lisp/calendar/icalendar-recur-tests.el b/test/lisp/calendar/icalendar-recur-tests.el
index 77e6f89744f..c864b8c15fa 100644
--- a/test/lisp/calendar/icalendar-recur-tests.el
+++ b/test/lisp/calendar/icalendar-recur-tests.el
@@ -1286,7 +1286,8 @@ from 1967 to at least 2026.")
   (let* ((dt (ical:make-date-time :year 1900 :month 1 :day 1
                                   :hour 12 :minute 0 :second 0
                                   :zone ict:est :dst nil))
-         (ts (encode-time dt)))
+         (ts (ignore-errors (encode-time dt))))
+    (skip-unless ts) ; Skip the test on platforms that can't represent 1900.
     (should (null (icr:tz-observance-on dt ict:tz-eastern)))
     (should (null (icr:tz-observance-on ts ict:tz-eastern))))
 
diff --git a/test/lisp/gnus/gnus-icalendar-tests.el b/test/lisp/gnus/gnus-icalendar-tests.el
index e668becd54d..7b26da3a3cf 100644
--- a/test/lisp/gnus/gnus-icalendar-tests.el
+++ b/test/lisp/gnus/gnus-icalendar-tests.el
@@ -116,6 +116,11 @@ END:VCALENDAR
 ;; FIXME: is "icalendary" (not "icalendar") intentional, here and below?
 (ert-deftest gnus-icalendary-byday ()
   ""
+  ;; Skip the test if encode-time rejects old dates.
+  ;; This test assumes underlying timekeeping works for dates in the 1600s,
+  ;; but POSIX requires only dates starting in 1970.
+  (skip-unless (ignore-errors (encode-time '(0 0 0 1 1 1601 1 nil -18000))))
+
   (let* ((tz (getenv "TZ"))
         (icalendar-pre-parsing-hook
          ;; clean up " <at> " addresses so the parser doesn't choke...