# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1438537004 -7200
# Node ID d938f5c114d6af4c7ed36947f7ac0e2a555a9e86
# Parent  6c23b78ed1551322210d64ceb80a6a5da76eb85a
Tidied time zone usage in period initialisation.

diff -r 6c23b78ed155 -r d938f5c114d6 imiptools/data.py
--- a/imiptools/data.py	Sun Aug 02 19:36:33 2015 +0200
+++ b/imiptools/data.py	Sun Aug 02 19:36:44 2015 +0200
@@ -614,7 +614,7 @@
     # Attempt to get time zone details from the object, using the supplied zone
     # only as a fallback.
 
-    tzid = obj.get_tzid() or tzid
+    obj_tzid = obj.get_tzid()
 
     if not rrule:
         periods = [RecurringPeriod(dtstart, dtend, tzid, "DTSTART", dtstart_attr, dtend_attr)]
@@ -631,14 +631,14 @@
 
         until = parameters.get("UNTIL")
         if until:
-            end = min(to_timezone(get_datetime(until, dtstart_attr), tzid), end)
+            end = min(to_timezone(get_datetime(until, dtstart_attr), obj_tzid), end)
             inclusive = True
 
         for recurrence_start in selector.materialise(dtstart, end, parameters.get("COUNT"), parameters.get("BYSETPOS"), inclusive):
             create = len(recurrence_start) == 3 and date or datetime
-            recurrence_start = to_timezone(create(*recurrence_start), tzid)
+            recurrence_start = to_timezone(create(*recurrence_start), obj_tzid)
             recurrence_end = recurrence_start + duration
-            periods.append(RecurringPeriod(recurrence_start, recurrence_end, tzid, "RRULE"))
+            periods.append(RecurringPeriod(recurrence_start, recurrence_end, tzid, "RRULE", dtstart_attr))
 
     else:
         periods = []
@@ -660,14 +660,14 @@
 
     # Exclude exception dates.
 
-    exdates = obj.get_date_values("EXDATE", tzid)
+    exdates = obj.get_date_value_items("EXDATE", tzid)
 
     if exdates:
-        for exdate in exdates:
+        for exdate, exdate_attr in exdates:
             if isinstance(exdate, tuple):
-                period = Period(exdate[0], exdate[1], tzid)
+                period = RecurringPeriod(exdate[0], exdate[1], tzid, "EXDATE", exdate_attr)
             else:
-                period = Period(exdate, exdate + duration, tzid)
+                period = RecurringPeriod(exdate, exdate + duration, tzid, "EXDATE", exdate_attr)
             i = bisect_left(periods, period)
             while i < len(periods) and periods[i] == period:
                 del periods[i]