fix bug 1769, ' vCalendar timezone glitches'

Patch by Darko Koruga

diff --git a/src/plugins/vcalendar/vcal_folder.c b/src/plugins/vcalendar/vcal_folder.c
index 76928f52b21b7f6860c5567de97f90c70afd6c18..399cefac71be92f8a7a602ece374b0b070adae67 100644 (file)
--- a/src/plugins/vcalendar/vcal_folder.c
+++ b/src/plugins/vcalendar/vcal_folder.c
@@ -2134,6 +2134,43 @@ static gchar *get_email_from_property(icalproperty *p)
        return email;
 }
 
+static void adjust_for_local_time_zone(icalproperty *eventtime, icalproperty *tzoffsetto, int dtstart)
+{
+       int tzoffset;
+       int loctzoffset;
+       time_t loctime, gmttime, evttime;
+       struct icaltimetype icaltime;
+
+       /* calculate local UTC offset */
+       loctime = time(NULL);
+       loctime = mktime(localtime(&loctime));
+       gmttime = mktime(gmtime(&loctime));
+       loctzoffset = loctime - gmttime;
+
+       if (eventtime && tzoffsetto) {
+               tzoffset = icalproperty_get_tzoffsetto(tzoffsetto);
+               if (dtstart) {
+                       evttime = icaltime_as_timet(icalproperty_get_dtstart(eventtime));
+               }
+               else {
+                       evttime = icaltime_as_timet(icalproperty_get_dtend(eventtime));
+               }
+
+               /* convert to UTC */
+               evttime -= tzoffset;
+               /* and adjust for local time zone */
+               evttime += loctzoffset;
+               icaltime = icaltime_from_timet(evttime, 0);
+
+               if (dtstart) {
+                       icalproperty_set_dtstart(eventtime, icaltime);
+               }
+               else {
+                       icalproperty_set_dtend(eventtime, icaltime);
+               } 
+       }
+}
+
 #define GET_PROP(comp,prop,kind) {                                             \
        prop = NULL;                                                            \
        if (!(prop = icalcomponent_get_first_property(comp, kind))) {           \
@@ -2173,6 +2210,7 @@ VCalEvent *vcal_get_event_from_ical(const gchar *ical, const gchar *charset)
        gchar *int_ical = g_strdup(ical);
        icalcomponent *comp = icalcomponent_new_from_string(int_ical);
        icalcomponent *inner = NULL;
+       icalcomponent *tzcomp = NULL;
        icalproperty *prop = NULL;
        GSList *list = NULL, *cur = NULL;
        gchar *uid = NULL;
@@ -2216,6 +2254,31 @@ VCalEvent *vcal_get_event_from_ical(const gchar *ical, const gchar *charset)
                TO_UTF8(summary);
                icalproperty_free(prop);
        }
+       tzcomp = icalcomponent_get_first_component(comp, ICAL_VTIMEZONE_COMPONENT);
+       if (tzcomp) {
+               icalproperty *evtstart = NULL;
+               icalproperty *evtend = NULL;
+               icalproperty *tzoffsetto = NULL;
+               icalcomponent *tzstd = NULL;
+
+               tzstd = icalcomponent_get_first_component(tzcomp, ICAL_XSTANDARD_COMPONENT);
+               tzoffsetto = icalcomponent_get_first_property(tzstd, ICAL_TZOFFSETTO_PROPERTY);
+
+               GET_PROP(comp, evtstart, ICAL_DTSTART_PROPERTY);
+               adjust_for_local_time_zone(evtstart, tzoffsetto, TRUE);
+
+               GET_PROP(comp, evtend, ICAL_DTEND_PROPERTY);
+               adjust_for_local_time_zone(evtend, tzoffsetto, FALSE);
+
+               if (tzoffsetto)
+                       icalproperty_free(tzoffsetto);
+               if (evtstart)
+                       icalproperty_free(evtstart);
+               if (evtend)
+                       icalproperty_free(evtend);
+               if (tzstd)
+                       icalcomponent_free(tzstd);
+       }
        GET_PROP(comp, prop, ICAL_DTSTART_PROPERTY);
        if (prop) {
                dtstart = g_strdup(icaltime_as_ical_string(icalproperty_get_dtstart(prop)));