[vala] libxml-2.0: Fix xmlGetProp/xmlGetNsProp/xmlGetNoNsProp bindings

[Jürg Billeter <juergbi src gnome org>]

commit 98785c272674bf54ff95e2fb8c035170c4288bbb
Author: Martin Olsson <martin minimum se>
Date:   Mon Sep 7 21:59:14 2009 +0200

    libxml-2.0: Fix xmlGetProp/xmlGetNsProp/xmlGetNoNsProp bindings
    
    Fixes bug 594414.

 vapi/libxml-2.0.vapi |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/vapi/libxml-2.0.vapi b/vapi/libxml-2.0.vapi
index 6b0f72e..5665b50 100644
--- a/vapi/libxml-2.0.vapi
+++ b/vapi/libxml-2.0.vapi
@@ -599,16 +599,16 @@ namespace Xml {
 		public long get_line_no ();
 
 		[CCode (cname = "xmlGetNoNsProp")]
-		public string get_no_ns_prop (string name);
+		public string? get_no_ns_prop (string name);
 
 		[CCode (cname = "xmlGetNodePath")]
 		public string get_path ();
 
 		[CCode (cname = "xmlGetNsProp")]
-		public string get_ns_prop (string name, string ns);
+		public string? get_ns_prop (string name, string ns);
 
 		[CCode (cname = "xmlGetProp")]
-		public string get_prop (string name);
+		public string? get_prop (string name);
 
 		[CCode (cname = "xmlHasNsProp")]
 		public Attr* has_ns_prop (string name, string name_space);