freeze break request: add org.a11y.Bus.IsEnabled

[Mike Gorse <mgorse novell com>]

A while ago, Frederik Gladhorn proposed an API to check whether 
accessibility is enabled and also to toggle it on or off at runtime:
https://mail.gnome.org/archives/desktop-devel-list/2011-May/msg00397.html

I would really like to implement the part of the proposal to check whether 
a11y is enabled; I ought to have done this sooner, but it slipped my mind, 
and I let API/feature freeze creep up on me.  Historically, third-party 
apps have checked gconf to determine whether accessibility is enabled and 
to enable their own accessibility code.  Unless it has been changed 
recently, Firefox is still doing this and so is inaccessible out of the 
box on a GNOME 3 system that was not created by upgrading a GNOME 2 system 
on which the user would have set the gconf key.  I am also planning one 
more Mono Accessibility release to clean up/modernize a few things, and 
this needs to be updated there as well.  Anyway, it seems preferable to 
have a way of checking whether accessibility is enabled that doesn't 
involve looking at a GSettings key, since other desktops (such as KDE ans 
XFCE) may support accessibility in the near future as well, and I would 
like for applications to be able to begin coding to it and have it 
function for GNOME 3.2 systems, so I really don't want this to have to 
wait for 3.4.  I'm attaching a patch.

Thanks,
-Mike G-

diff --git a/src/BusObject.cs b/src/BusObject.cs
index 8106023..35693b5 100644
--- a/src/BusObject.cs
+++ b/src/BusObject.cs
@@ -13,6 +13,7 @@ namespace NDesk.DBus
 	{
 		protected Connection conn;
 		string bus_name;
+		string alt_bus_name;
 		ObjectPath object_path;
 
 		//protected BusObject ()
@@ -55,6 +56,7 @@ namespace NDesk.DBus
 			rule.Fields.Add (FieldCode.Interface, new MatchTest (iface));
 			rule.Fields.Add (FieldCode.Member, new MatchTest (member));
 			rule.Fields.Add (FieldCode.Path, new MatchTest (object_path));
+			rule.Fields.Add (FieldCode.Sender, new MatchTest (alt_bus_name != null? alt_bus_name: bus_name));
 
 			if (adding) {
 				if (conn.Handlers.ContainsKey (rule))
@@ -218,12 +220,16 @@ namespace NDesk.DBus
 #endif
 
 			Message retMsg = conn.SendWithReplyAndBlock (callMsg);
+Console.WriteLine ("dbg: sender: " + retMsg.Header[FieldCode.Sender]);
 
 			MessageReader retVal = null;
 
 			//handle the reply message
 			switch (retMsg.Header.MessageType) {
 				case MessageType.MethodReturn:
+				if ((string)retMsg.Header[FieldCode.Sender] != bus_name)
+					alt_bus_name = (string)retMsg.Header[FieldCode.Sender];
+if ((string)retMsg.Header[FieldCode.Sender] != bus_name) Console.WriteLine ("dbg: new name--magic! " + bus_name + " -> " + alt_bus_name);
 					retVal = new MessageReader (retMsg);
 				break;
 				case MessageType.Error:
diff --git a/src/Connection.cs b/src/Connection.cs
index 6a62647..7061b34 100644
--- a/src/Connection.cs
+++ b/src/Connection.cs
@@ -324,10 +324,13 @@ namespace NDesk.DBus
 			rule.MessageType = MessageType.Signal;
 			rule.Fields.Add (FieldCode.Interface, new MatchTest (signal.Interface));
 			rule.Fields.Add (FieldCode.Member, new MatchTest (signal.Member));
+			rule.Fields.Add (FieldCode.Sender, new MatchTest (signal.Sender));
+Console.WriteLine ("dbg: signal: " + signal.Member);
 			rule.Fields.Add (FieldCode.Path, new MatchTest (signal.Path));
 
 			Delegate dlg;
 			if (Handlers.TryGetValue (rule, out dlg) && dlg != null) {
+Console.WriteLine ("dbg: found");
 				MethodInfo mi = dlg.GetType ().GetMethod ("Invoke");
 
 				bool compatible = false;