[vala] Fix crash on invalid field initializer

[Jürg Billeter <juergbi src gnome org>]

commit 918c07568d44aae0fb3ba30e83f58c866dddeeb3
Author: Jürg Billeter <j bitron ch>
Date:   Mon Mar 22 23:27:33 2010 +0100

    Fix crash on invalid field initializer
    
    Fixes bug 608635.

 vala/valafield.vala    |    8 +++++++-
 vala/valaproperty.vala |    4 ++--
 2 files changed, 9 insertions(+), 3 deletions(-)
---
diff --git a/vala/valafield.vala b/vala/valafield.vala
index 87d12c1..b038c72 100644
--- a/vala/valafield.vala
+++ b/vala/valafield.vala
@@ -1,6 +1,6 @@
 /* valafield.vala
  *
- * Copyright (C) 2006-2009  Jürg Billeter
+ * Copyright (C) 2006-2010  Jürg Billeter
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -324,6 +324,12 @@ public class Vala.Field : Member, Lockable {
 				return false;
 			}
 
+			if (initializer.value_type == null) {
+				error = true;
+				Report.error (source_reference, "expression type not allowed as initializer");
+				return false;
+			}
+
 			if (!initializer.value_type.compatible (field_type)) {
 				error = true;
 				Report.error (source_reference, "Cannot convert from `%s' to `%s'".printf (initializer.value_type.to_string (), field_type.to_string ()));
diff --git a/vala/valaproperty.vala b/vala/valaproperty.vala
index e00a21b..ac15b8e 100644
--- a/vala/valaproperty.vala
+++ b/vala/valaproperty.vala
@@ -1,6 +1,6 @@
 /* valaproperty.vala
  *
- * Copyright (C) 2006-2009  Jürg Billeter
+ * Copyright (C) 2006-2010  Jürg Billeter
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -471,7 +471,7 @@ public class Vala.Property : Member, Lockable {
 			}
 		}
 
-		if (default_expression != null && !default_expression.error && !(default_expression.value_type.compatible (property_type))) {
+		if (default_expression != null && !default_expression.error && default_expression.value_type != null && !(default_expression.value_type.compatible (property_type))) {
 			error = true;
 			Report.error (default_expression.source_reference, "Expected initializer of type `%s' but got `%s'".printf (property_type.to_string (), default_expression.value_type.to_string ()));
 		}