calendar: make freeing a calendar spec object deal fine with NULL

In order to make object destruction easier (in particular in combination
with _cleanup_) we usually make destructors deal with NULL objects as
NOPs. Change the calendar spec destructor to follow the same scheme.

1 files changed, 3 insertions, 1 deletions

diff --git a/src/shared/calendarspec.c b/src/shared/calendarspec.c
index 69b7427232..4ac74ab0a2 100644
--- a/src/shared/calendarspec.c
+++ b/src/shared/calendarspec.c
@@ -35,7 +35,9 @@ static void free_chain(CalendarComponent *c) {
 }
 
 void calendar_spec_free(CalendarSpec *c) {
-        assert(c);
+
+        if (!c)
+                return;
 
         free_chain(c->year);
         free_chain(c->month);