[gnome-boxes] app: Avoid adding duplicate sources

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 6b95a50c21747497a30cc68e4afc9859b0ab2b80
Author: Zeeshan Ali (Khattak) <zeeshanak gnome org>
Date:   Fri Mar 29 04:55:17 2013 +0200

    app: Avoid adding duplicate sources
    
    Without this fix, we were adding the default 'QEMU Session' source
    twice. It hasn't been a real problem so far but it will be after we
    starting deleting stale box configs in the following patches.
    
    We are now simply moving the add_collection_source out of
    foreach_filename_from_dir's callback as we can't yield in there because
    of bug#604827 and removing the explicit addition of 'QEMU Session'
    source as it becomes redundant with this patch.
    
    We were launching add_collection_source *async* for each source we found.
    Since add_collection_source() checks if source is already added *before*
    defering to mainloop, we could have a scenario like this:
    
    1. source 'A' is found and add_collection source() defers to mainloop.
    2. source 'B' (which is a duplicate of 'A') is found and
    add_collection_source is launched for it too.
    3. The add_collection source() from #1 has not yet added source 'A' so
    the check for duplicate will fail and we'll still have a duplicated
    source added.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683489

 src/app.vala |   27 +++++++++++++++------------
 1 files changed, 15 insertions(+), 12 deletions(-)
---
diff --git a/src/app.vala b/src/app.vala
index c612e56..872d8e8 100644
--- a/src/app.vala
+++ b/src/app.vala
@@ -365,6 +365,11 @@ private class Boxes.App: Boxes.UI {
         if (!source.enabled)
             return;
 
+        if (sources.get (source.name) != null) {
+            warning ("Attempt to add duplicate collection source '%s', ignoring..", source.name);
+            return; // Already added
+        }
+
         switch (source.source_type) {
         case "vnc":
         case "spice":
@@ -404,23 +409,21 @@ private class Boxes.App: Boxes.UI {
             }
         }
 
-        try {
-            var source = new CollectionSource.with_file ("QEMU Session");
-            yield add_collection_source (source);
-        } catch (GLib.Error error) {
-            warning (error.message);
-        }
-        if (default_connection == null) {
-            printerr ("Missing or failing default libvirt connection\n");
-            application.release (); // will end application
-        }
-
         var dir = File.new_for_path (get_user_pkgconfig_source ());
+        var new_sources = new GLib.List<CollectionSource> ();
         yield foreach_filename_from_dir (dir, (filename) => {
             var source = new CollectionSource.with_file (filename);
-            add_collection_source.begin (source);
+            new_sources.append (source);
             return false;
         });
+
+        foreach (var source in new_sources)
+            yield add_collection_source (source);
+
+        if (default_connection == null) {
+            printerr ("Missing or failing default libvirt connection\n");
+            application.release (); // will end application
+        }
     }
 
     private void save_window_geometry () {