From: Ulf Jasper <ulf.jasper@web.de>
Date: Wed, 30 Jul 2014 16:25:58 +0000 (+0200)
Subject: Fix Bug#15408 (icalendar time zone problem)
X-Git-Tag: emacs-25.0.90~2636^3~4
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=c99a3b8705aad133d90b634989f6f7ad1559b7b5;p=emacs.git

Fix Bug#15408 (icalendar time zone problem)

2014-07-30 Christophe Deleuze <christophe.deleuze@free.fr>

	* calendar/icalendar.el (icalendar--decode-isodatetime): Use
	actual current-time-zone when converting to local time. (Bug#15408)

2014-07-30  Ulf Jasper  <ulf.jasper@web.de>

	* automated/icalendar-tests.el (icalendar--decode-isodatetime): New test.
---

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a89b46bf144..5bebc3af3b9 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-07-30 Christophe Deleuze <christophe.deleuze@free.fr>
+
+	* calendar/icalendar.el (icalendar--decode-isodatetime): Use
+	actual current-time-zone when converting to local time. (Bug#15408)
+
 2014-07-29  Martin Rudalics  <rudalics@gmx.at>
 
 	* window.el (window--state-put-2): Handle horizontal scroll
diff --git a/lisp/calendar/icalendar.el b/lisp/calendar/icalendar.el
index 4ba4869d788..9aefcac2314 100644
--- a/lisp/calendar/icalendar.el
+++ b/lisp/calendar/icalendar.el
@@ -563,7 +563,12 @@ FIXME: multiple comma-separated values should be allowed!"
                    ;; UTC specifier present
                    (char-equal ?Z (aref isodatetimestring 15)))
           ;; if not UTC add current-time-zone offset
-          (setq second (+ (car (current-time-zone)) second)))
+          ;; current-time-zone should be called with actual UTC time
+          ;; (daylight saving at that time may differ to current one)
+          (setq second (+ (car (current-time-zone
+                                (encode-time second minute hour day month year
+                                             0)))
+                          second)))
         ;; shift if necessary
         (if day-shift
             (let ((mdy (calendar-gregorian-from-absolute
diff --git a/test/ChangeLog b/test/ChangeLog
index 140b5d04efd..4e47f95b066 100644
--- a/test/ChangeLog
+++ b/test/ChangeLog
@@ -1,3 +1,7 @@
+2014-07-30  Ulf Jasper  <ulf.jasper@web.de>
+
+	* automated/icalendar-tests.el (icalendar--decode-isodatetime): New test.
+
 2014-07-28  Dmitry Antipov  <dmantipov@yandex.ru>
 
 	* automated/timer-tests.el (timer-tests-debug-timer-check): New test.
diff --git a/test/automated/icalendar-tests.el b/test/automated/icalendar-tests.el
index 7b51f907d38..2ffa3911ee3 100644
--- a/test/automated/icalendar-tests.el
+++ b/test/automated/icalendar-tests.el
@@ -414,6 +414,38 @@ END:VEVENT
     (should (not result))
     ))
 
+(ert-deftest icalendar--decode-isodatetime ()
+  "Test `icalendar--decode-isodatetime'."
+  (let ((tz (getenv "TZ"))
+	result)
+    (unwind-protect
+	(progn
+	  ;; Use Eastern European Time (UTC+1, UTC+2 daylight saving)
+	  (setenv "TZ" "EET")
+
+          (message "%s" (current-time-zone (encode-time 0 0 10 1 1 2013 0)))
+          (message "%s" (current-time-zone (encode-time 0 0 10 1 8 2013 0)))
+
+          ;; testcase: no time zone in input -> keep time as is
+          ;; 1 Jan 2013 10:00
+          (should (equal '(0 0 10 1 1 2013 2 nil 7200)
+                         (icalendar--decode-isodatetime "20130101T100000")))
+          ;; 1 Aug 2013 10:00 (DST)
+          (should (equal '(0 0 10 1 8 2013 4 t 10800)
+                         (icalendar--decode-isodatetime "20130801T100000")))
+
+          ;; testcase: UTC time zone specifier in input -> convert to local time
+          ;; 31 Dec 2013 23:00 UTC -> 1 Jan 2013 01:00 EET
+          (should (equal '(0 0 1 1 1 2014 3 nil 7200)
+                         (icalendar--decode-isodatetime "20131231T230000Z")))
+          ;; 1 Aug 2013 10:00 UTC -> 1 Aug 2013 13:00 EEST
+          (should (equal '(0 0 13 1 8 2013 4 t 10800)
+                         (icalendar--decode-isodatetime "20130801T100000Z")))
+
+          )
+      ;; restore time-zone even if something went terribly wrong
+      (setenv "TZ" tz)))  )
+
 ;; ======================================================================
 ;; Export tests
 ;; ======================================================================