[gnome-desktop] GnomeWallClock: Fix non-Linux fallback code

[Colin Walters <walters src gnome org>]

commit 7033804a455ccd39997632c164b5fae3e4fedac4
Author: Colin Walters <walters verbum org>
Date:   Mon Oct 3 16:35:20 2011 -0400

    GnomeWallClock: Fix non-Linux fallback code
    
    This fixes the "infinite loop in gnome-screensaver" bug.  Only
    dispatch in cancel on set when the monotonic timeout has expired,
    otherwise we will drop into a tight loop.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=660343

 libgnome-desktop/gnome-datetime-source.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/libgnome-desktop/gnome-datetime-source.c b/libgnome-desktop/gnome-datetime-source.c
index 05ec80a..a35d5b3 100644
--- a/libgnome-desktop/gnome-datetime-source.c
+++ b/libgnome-desktop/gnome-datetime-source.c
@@ -57,8 +57,10 @@ static gboolean
 g_datetime_source_is_expired (GDateTimeSource *datetime_source)
 {
 	gint64 real_now;
+	gint64 monotonic_now;
 
 	real_now = g_get_real_time ();
+	monotonic_now = g_source_get_time ((GSource*)datetime_source);
 
 	if (datetime_source->initially_expired)
 		return TRUE;
@@ -66,10 +68,11 @@ g_datetime_source_is_expired (GDateTimeSource *datetime_source)
 	if (datetime_source->real_expiration <= real_now)
 		return TRUE;
 
-	/* We can't really detect without system support when things change;
-	 * so just trigger every second.
+	/* We can't really detect without system support when things
+	 * change; so just trigger every second (i.e. our wakeup
+	 * expiration)
 	 */
-	if (datetime_source->cancel_on_set)
+	if (datetime_source->cancel_on_set && monotonic_now >= datetime_source->wakeup_expiration)
 		return TRUE;
 
 	return FALSE;