[vala] Fix passing delegate field without target as method argument

[Jürg Billeter <juergbi src gnome org>]

commit 02ff2455fe5f21d06ca431b078a15de03eaf3144
Author: Jürg Billeter <j bitron ch>
Date:   Wed Mar 24 08:52:04 2010 +0100

    Fix passing delegate field without target as method argument
    
    Fixes bug 592769.

 codegen/valaccodedelegatemodule.vala |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/codegen/valaccodedelegatemodule.vala b/codegen/valaccodedelegatemodule.vala
index 7213707..bcb62a2 100644
--- a/codegen/valaccodedelegatemodule.vala
+++ b/codegen/valaccodedelegatemodule.vala
@@ -254,6 +254,10 @@ internal class Vala.CCodeDelegateModule : CCodeArrayModule {
 
 				CCodeExpression target_expr = null;
 
+				if (field.no_delegate_target) {
+					return new CCodeConstant ("NULL");
+				}
+
 				if (field.binding == MemberBinding.INSTANCE) {
 					var instance_expression_type = ma.inner.value_type;
 					var instance_target_type = get_data_type_for_symbol ((TypeSymbol) field.parent_symbol);