libzeitgeist: add "null event" handling

GetEvents returns null-events when a requested ID doesn't exist.

This commit fixes libzeitgeist to properly support this, by changing
zeitgeist_log_get_events to return GenericArray<Event?>.

https://bugs.freedesktop.org/show_bug.cgi?id=53016

3 files changed, 32 insertions, 10 deletions

diff --git a/libzeitgeist/API_CHANGES b/libzeitgeist/API_CHANGES
index 2357895e..e528dc2f 100644
--- a/libzeitgeist/API_CHANGES
+++ b/libzeitgeist/API_CHANGES
@@ -15,6 +15,8 @@ API CHANGES FROM LIBZEITGEIST1:
  - introduced zeitgeist_time_range_intersect
  - removed time_range_get_{start,end}_iso8601
  - changed timestamp_for_now to be timestamp_now
+ - zeitgeist_log_get_events now returns GPtrArray (and works
+   with NULL-events)
 
 Vala:
  - stuff is more valaish (eg. properties vs set/get)
diff --git a/libzeitgeist/datamodel.vala b/libzeitgeist/datamodel.vala
index 19d47e36..b6b51246 100644
--- a/libzeitgeist/datamodel.vala
+++ b/libzeitgeist/datamodel.vala
@@ -29,6 +29,7 @@ namespace Zeitgeist
     [DBus (name = "org.gnome.zeitgeist.DataModelError")]
     public errordomain DataModelError {
         INVALID_SIGNATURE,
+        NULL_EVENT,
         TOO_MANY_RESULTS
     }
 
@@ -429,6 +430,12 @@ namespace Zeitgeist
             Variant payload_variant = iter.next_value ();
 
             var event_props = event_array.n_children ();
+
+            if (event_props == 0)
+            {
+                throw new DataModelError.NULL_EVENT ("This is an empty event.");
+            }
+
             assert_sig (event_props >= 5, "Missing event information.");
             id = (uint32) uint64.parse (event_array.next_value().get_string ());
             var str_timestamp = event_array.next_value().get_string ();
@@ -595,14 +602,26 @@ namespace Zeitgeist
     namespace Events
     {
 
-        public static GenericArray<Event> from_variant (Variant vevents)
+        public static GenericArray<Event?> from_variant (Variant vevents)
             throws DataModelError
         {
-            GenericArray<Event> events = new GenericArray<Event> ();
+            GenericArray<Event?> events = new GenericArray<Event> ();
 
             assert (vevents.get_type_string () == "a("+Utils.SIG_EVENT+")");
-            foreach (Variant event in vevents)
-                events.add (new Event.from_variant (event));
+            foreach (Variant vevent in vevents)
+            {
+                Event? event = null;
+                try
+                {
+                    event = new Event.from_variant (vevent);
+                }
+                catch (DataModelError err)
+                {
+                    if (!(err is DataModelError.NULL_EVENT))
+                        throw err;
+                }
+                events.add (event);
+            }
 
             return events;
         }
diff --git a/libzeitgeist/log.vala b/libzeitgeist/log.vala
index 47e33114..0460a5f2 100644
--- a/libzeitgeist/log.vala
+++ b/libzeitgeist/log.vala
@@ -154,16 +154,16 @@ public class Log : QueuedProxyWrapper
             num_events, result_type, cancellable);
     }
 
-    public async ResultSet get_events (
-                Array<uint32> event_ids,
-            Cancellable? cancellable=null) throws Error
+    public async GenericArray<Event> get_events (
+        Array<uint32> event_ids,
+        Cancellable? cancellable=null) throws Error
     {
         yield wait_for_proxy ();
         uint32[] simple_event_ids = new uint32[event_ids.length];
-        for (int i=0; i<event_ids.length; i++)
-            simple_event_ids[i] = event_ids.index(i);
+        for (int i = 0; i < event_ids.length; i++)
+            simple_event_ids[i] = event_ids.index (i);
         var result = yield proxy.get_events (simple_event_ids, cancellable);
-        return new SimpleResultSet (Events.from_variant (result));
+        return Events.from_variant (result);
     }
 
     public async string[] find_related_uris (
@@ -218,6 +218,7 @@ public class Log : QueuedProxyWrapper
         {
             DBusConnection conn = ((DBusProxy) proxy).get_connection ();
 
+            // FIXME: check exception
             uint registration_id = conn.register_object<RemoteMonitor> (
                 monitor.get_path (), monitor);
             monitors.insert (monitor, registration_id);