From: Art Cancro <ajc@citadel.org>
Date: Thu, 21 Mar 2024 18:30:29 +0000 (-0700)
Subject: Do not convert compared times to UTC.
X-Git-Tag: v999~18
X-Git-Url: https://code.citadel.org/?p=citadel.git;a=commitdiff_plain;h=a0bffa36078be5c70149923399fba348494d8e5c

Do not convert compared times to UTC.

ical_ctdl_is_overlap() works because icaltime_compare() is really smart.
It looks at the time zone of the dtstart/dtend and can apparently go back up the icalcomponent
hierarchy to find its time zone data.  I tested this by creating an event with a fictional
time zone and it did the right thing.  It even showed the fictional name to me.  This saves us
from having to convert everything to UTC before comparing.  Nice!
---

diff --git a/citadel/server/modules/calendar/ical_ctdl_is_overlap.c b/citadel/server/modules/calendar/ical_ctdl_is_overlap.c
index d980c554b..fbec0f572 100644
--- a/citadel/server/modules/calendar/ical_ctdl_is_overlap.c
+++ b/citadel/server/modules/calendar/ical_ctdl_is_overlap.c
@@ -38,11 +38,11 @@ int ical_ctdl_is_overlap(
 	}
 
 #ifdef DEBUG_ICAL_OVERLAP
-	syslog(LOG_DEBUG, "Comparing t1start=%s,t1end=%s to t2start=%s,t2end=%s",
-		icaltime_as_ical_string_r(t1start),
-		icaltime_as_ical_string_r(t1end),
-		icaltime_as_ical_string_r(t2start),
-		icaltime_as_ical_string_r(t2end)
+	syslog(LOG_DEBUG, "Comparing t1start=%s(%s),t1end=%s(%s) to t2start=%s(%s),t2end=%s(%s)",
+		icaltime_as_ical_string_r(t1start),	icaltime_get_tzid(t1start),
+		icaltime_as_ical_string_r(t1end),	icaltime_get_tzid(t1end),
+		icaltime_as_ical_string_r(t2start),	icaltime_get_tzid(t2start),
+		icaltime_as_ical_string_r(t2end),	icaltime_get_tzid(t2end)
 	);
 #endif
 
diff --git a/webcit-ng/server/caldav_reports.c b/webcit-ng/server/caldav_reports.c
index 3c7797eed..481d118d1 100644
--- a/webcit-ng/server/caldav_reports.c
+++ b/webcit-ng/server/caldav_reports.c
@@ -259,7 +259,7 @@ void caldav_report_one_item(struct http_transaction *h, struct ctdlsession *c, S
 
 // Compare function for "time-range" tests (RFC4791 section 9.9)
 // Returns nonzero if the supplied icalcomponent occurs within the specified time range
-int caldav_time_range_filter_matches(icalcomponent *cal_in, char *start_str, char *end_str) {
+int caldav_time_range_filter_matches(icalcomponent *cal, char *start_str, char *end_str) {
 
 	struct icaltimetype start = (
 		(!IsEmptyStr(start_str))
@@ -275,20 +275,12 @@ int caldav_time_range_filter_matches(icalcomponent *cal_in, char *start_str, cha
 	);
 	syslog(LOG_DEBUG, "   search   end: %16s --> \033[36m%s\033[0m", end_str, icaltime_as_ical_string_r(end));
 
-
-// NOTE TO ME: The header file says
-// "This converts both times to the UTC timezone and compares them."
-//	LIBICAL_ICAL_EXPORT int icaltime_compare(const struct icaltimetype a, const struct icaltimetype b);
-// How does it do that without knowing the time zone?  Does it use a private method to look up into the
-// parent component to find a VTIMEZONE component?  Find out.  If it can do that, we don't have to dezonify.
-
-
-
-	// make a local copy of the component because we are going to modify it by converting times to UTC
-	icalcomponent *cal = icalcomponent_new_clone(cal_in);
-	ical_dezonify(cal);
-
-
+	// IMPLEMENTATION NOTE:
+	// ical_ctdl_is_overlap() works because icaltime_compare() is really smart.
+	// It looks at the time zone of the dtstart/dtend and can apparently go back up the icalcomponent
+	// hierarchy to find its time zone data.  I tested this by creating an event with a fictional
+	// time zone and it did the right thing.  It even showed the fictional name to me.  This saves us
+	// from having to convert everything to UTC before comparing.  Nice!
 
 	icaltimetype dts = icalcomponent_get_dtstart(cal);
 	syslog(LOG_DEBUG, "component start: \033[36m%s\033[0m", icaltime_as_ical_string_r(dts));
@@ -296,10 +288,7 @@ int caldav_time_range_filter_matches(icalcomponent *cal_in, char *start_str, cha
 	icaltimetype dte = icalcomponent_get_dtend(cal);
 	syslog(LOG_DEBUG, "component   end: \033[36m%s\033[0m", icaltime_as_ical_string_r(dte));
 
-	int result = ical_ctdl_is_overlap(dts, dte, start, end);	// We have a convenience function for this.
-
-	icalcomponent_free(cal);
-	return(result);
+	return(ical_ctdl_is_overlap(dts, dte, start, end));	// We have a convenience function for this.
 }