build: Support libical 4

libical 4 changed several APIs used by GNOME Calendar:

 - libical-glib now provides autoptr cleanup for ICalTime, so only
   define it ourselves for older versions.
 - i_cal_recurrence_get/set_by_day() were removed in favor of the
   dynamically sized by-rule arrays; add local helpers on top of
   i_cal_recurrence_get/set_by().
 - i_cal_errno_return() was renamed to i_cal_error_icalerrno().

Also make the create-tzid event test independent of line folding,
which differs between libical versions.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/core/gcal-recurrence.c

@@ -22,6 +22,30 @@
 
 #include <glib.h>
 
+#if ICAL_MAJOR_VERSION >= 4
+/* libical 4 replaced the fixed-size by_day array with dynamically sized arrays */
+static gshort
+i_cal_recurrence_get_by_day (ICalRecurrence *rrule,
+                             guint           index)
+{
+  if (index >= i_cal_recurrence_get_by_array_size (rrule, I_CAL_BY_DAY))
+    return -1;
+
+  return i_cal_recurrence_get_by (rrule, I_CAL_BY_DAY, index);
+}
+
+static void
+i_cal_recurrence_set_by_day (ICalRecurrence *rrule,
+                             guint           index,
+                             gshort          value)
+{
+  if (index >= i_cal_recurrence_get_by_array_size (rrule, I_CAL_BY_DAY))
+    i_cal_recurrence_resize_by_array (rrule, I_CAL_BY_DAY, index + 1);
+
+  i_cal_recurrence_set_by (rrule, I_CAL_BY_DAY, index, value);
+}
+#endif
+
 G_DEFINE_BOXED_TYPE (GcalRecurrence, gcal_recurrence, gcal_recurrence_ref, gcal_recurrence_unref)
 
 static void

src/gui/importer/gcal-importer.c

@@ -147,7 +147,11 @@ read_file_in_thread (GTask        *task,
   g_assert (g_utf8_validate (contents, length, NULL));
 
   component = i_cal_parser_parse_string (contents);
+#if ICAL_MAJOR_VERSION >= 4
+  ical_error = i_cal_error_icalerrno ();
+#else
   ical_error = i_cal_errno_return ();
+#endif
 
   if (ical_error != I_CAL_NO_ERROR)
     {

src/utils/gcal-utils.h

@@ -60,7 +60,9 @@ typedef void (*GcalAskRecurrenceCallback) (GcalEvent             *event,
                                            GcalRecurrenceModType  modtype,
                                            gpointer               user_data);
 
+#if ICAL_MAJOR_VERSION < 4
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (ICalTime, g_object_unref)
+#endif
 
 gchar*               gcal_util_get_weekday                       (gint                i);
 

tests/test-event.c

@@ -323,6 +323,7 @@ event_date_create_tzid (void)
   g_autoptr (GDateTime) datetime = NULL;
   g_autoptr (GTimeZone) tz = NULL;
   g_autofree gchar *ical_string = NULL;
+  GString *unfolded = NULL;
 
   ECalComponent *comp = NULL;
   ICalComponent *ical_comp = NULL;
@@ -352,9 +353,12 @@ event_date_create_tzid (void)
   datetime = g_date_time_new (tz, 2017, 8, 18, 3, 00, 00.);
   gcal_event_set_date_end (event, datetime);
 
-  ical_string = i_cal_component_as_ical_string (ical_comp);
+  /* Unfold lines, since the folding position differs between libical versions */
+  unfolded = g_string_new_take (i_cal_component_as_ical_string (ical_comp));
+  g_string_replace (unfolded, "\r\n ", "", 0);
+  ical_string = g_string_free (g_steal_pointer (&unfolded), FALSE);
   g_assert_true (strstr (ical_string, "DTSTART;TZID=Europe/London:20170818T010000\r\n") != NULL);
-  g_assert_true (strstr (ical_string, "DTEND;TZID=/freeassociation.sourceforge.net/Europe/London:\r\n 20170818T030000\r\n") != NULL);
+  g_assert_true (strstr (ical_string, "DTEND;TZID=/freeassociation.sourceforge.net/Europe/London:20170818T030000\r\n") != NULL);
   g_clear_pointer (&ical_string, g_free);
 
   g_setenv ("TZ", "UTC", TRUE);