[vala] Fix `this' access in default signal handlers

[Jürg Billeter <juergbi src gnome org>]

commit a8f55b462213540c644936fa52693f0e2d039cc0
Author: Yu Feng <rainwoodman gmail com>
Date:   Mon Aug 31 20:21:45 2009 -0400

    Fix `this' access in default signal handlers
    
    Fixes bug 593734.

 vala/valaclass.vala  |   30 ++++++++++++++++++++++++++++++
 vala/valasignal.vala |    7 ++++++-
 2 files changed, 36 insertions(+), 1 deletions(-)
---
diff --git a/vala/valaclass.vala b/vala/valaclass.vala
index dad8b8a..bf4105e 100644
--- a/vala/valaclass.vala
+++ b/vala/valaclass.vala
@@ -361,6 +361,36 @@ public class Vala.Class : ObjectTypeSymbol {
 	}
 	
 	/**
+	 * Adds the specified method as a hidden member to this class,
+	 * primarily used for default signal handlers.
+	 *
+	 * The hidden methods are not part of the `methods` collection.
+	 *
+	 * There may also be other use cases, eg, convert array.resize() to
+	 * this type of method?
+	 *
+	 * @param m a method
+	 */
+	public void add_hidden_method (Method m) {
+		if (m.binding == MemberBinding.INSTANCE) {
+			if (m.this_parameter != null) {
+				m.scope.remove (m.this_parameter.name);
+			}
+			m.this_parameter = new FormalParameter ("this", get_this_type ());
+			m.scope.add (m.this_parameter.name, m.this_parameter);
+		}
+		if (!(m.return_type is VoidType) && m.get_postconditions ().size > 0) {
+			if (m.result_var != null) {
+				m.scope.remove (m.result_var.name);
+			}
+			m.result_var = new LocalVariable (m.return_type.copy (), "result");
+			m.result_var.is_result = true;
+		}
+
+		scope.add (null, m);
+	}
+
+	/**
 	 * Returns a copy of the list of methods.
 	 *
 	 * @return list of methods
diff --git a/vala/valasignal.vala b/vala/valasignal.vala
index f51a922..a30e112 100644
--- a/vala/valasignal.vala
+++ b/vala/valasignal.vala
@@ -247,6 +247,8 @@ public class Vala.Signal : Member, Lockable {
 
 		if (is_virtual) {
 			default_handler = new Method (name, return_type, source_reference);
+
+			default_handler.owner = owner;
 			default_handler.access = access;
 			default_handler.external = external;
 			default_handler.is_virtual = true;
@@ -254,11 +256,14 @@ public class Vala.Signal : Member, Lockable {
 			default_handler.signal_reference = this;
 			default_handler.body = body;
 
+
 			foreach (FormalParameter param in parameters) {
 				default_handler.add_parameter (param);
 			}
 
-			parent_symbol.scope.add (null, default_handler);
+			var cl = parent_symbol as Class;
+
+			cl.add_hidden_method (default_handler);
 			default_handler.check (analyzer);
 		}
 		return !error;