[Atk] Fix leak caused by circular referencing in Atk code. (#2293)

The action code was creating a circular ref between the accessible and the object via the signals. Break all the refs.

1 files changed, 33 insertions, 25 deletions

diff --git a/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.AtkCocoaHelper/AtkCocoaHelper.cs b/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.AtkCocoaHelper/AtkCocoaHelper.cs
index 443255181a..cfb35700cc 100644
--- a/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.AtkCocoaHelper/AtkCocoaHelper.cs
+++ b/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.AtkCocoaHelper/AtkCocoaHelper.cs
@@ -113,34 +113,39 @@ namespace MonoDevelop.Components.AtkCocoaHelper
 					return;
 				}
 
-				var signal = GLib.Signal.Lookup (owner, "request-actions", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (RequestActionsHandler));
-
-				signal = GLib.Signal.Lookup (owner, "perform-cancel", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformCancelHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-confirm", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformConfirmHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-decrement", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformDecrementHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-delete", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformDeleteHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-increment", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformIncrementHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-pick", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformPickHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-press", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformPressHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-raise", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformRaiseHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-show-alternate-ui", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformShowAlternateUIHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-show-default-ui", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformShowDefaultUIHandler));
-				signal = GLib.Signal.Lookup (owner, "perform-show-menu", typeof (GLib.SignalArgs));
-				signal.AddDelegate (new EventHandler<GLib.SignalArgs> (PerformShowMenuHandler));
+				HandleSignalAttachment (owner, (signal, handler) => signal.AddDelegate (handler));
 			}
 		}
 
+		void HandleSignalAttachment (Atk.Object owner, Action<GLib.Signal, EventHandler<GLib.SignalArgs>> action)
+		{
+			var signal = GLib.Signal.Lookup (owner, "request-actions", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (RequestActionsHandler));
+
+			signal = GLib.Signal.Lookup (owner, "perform-cancel", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformCancelHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-confirm", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformConfirmHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-decrement", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformDecrementHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-delete", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformDeleteHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-increment", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformIncrementHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-pick", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformPickHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-press", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformPressHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-raise", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformRaiseHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-show-alternate-ui", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformShowAlternateUIHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-show-default-ui", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformShowDefaultUIHandler));
+			signal = GLib.Signal.Lookup (owner, "perform-show-menu", typeof (GLib.SignalArgs));
+			action (signal, new EventHandler<GLib.SignalArgs> (PerformShowMenuHandler));
+		}
+
 		public ActionDelegate (Gtk.Widget widget)
 		{
 			widget.Destroyed += WidgetDestroyed;
@@ -150,6 +155,9 @@ namespace MonoDevelop.Components.AtkCocoaHelper
 		void WidgetDestroyed (object sender, EventArgs e)
 		{
 			FreeActions ();
+
+			HandleSignalAttachment (owner, (signal, handler) => signal.RemoveDelegate (handler));
+			owner = null;
 		}
 
 		// Because the allocated memory is passed to unmanaged code where it cannot be freed