[hyena] SafeUri: prefer ANE over possible NRE

[AndrÃs Aragoneses <aaragoneses src gnome org>]

commit 9c316ab5e38cf3b2fcbfa32581d893f2d937cd4c
Author: Andres G. Aragoneses <knocte gmail com>
Date:   Thu Sep 15 18:30:02 2011 +0100

    SafeUri: prefer ANE over possible NRE
    
    ArgumentNullExceptions in the ctors are preferred over
    the NullReferenceException ones because they provide
    more information about the failure.

 Hyena/Hyena/SafeUri.cs |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/Hyena/Hyena/SafeUri.cs b/Hyena/Hyena/SafeUri.cs
index 04535e3..0afa310 100644
--- a/Hyena/Hyena/SafeUri.cs
+++ b/Hyena/Hyena/SafeUri.cs
@@ -48,6 +48,10 @@ namespace Hyena
 
         public SafeUri (string uri)
         {
+            if (String.IsNullOrEmpty (uri)) {
+                throw new ArgumentNullException ("uri");
+            }
+
             int scheme_delimit_index = uri.IndexOf ("://", StringComparison.InvariantCulture);
             if (scheme_delimit_index > 0 && scheme_delimit_index <= MAX_SCHEME_LENGTH) {
                 this.uri = uri;
@@ -58,6 +62,10 @@ namespace Hyena
 
         public SafeUri (string uri, bool isUri)
         {
+            if (String.IsNullOrEmpty (uri)) {
+                throw new ArgumentNullException ("uri");
+            }
+
             if (isUri) {
                 this.uri = uri;
             } else {
@@ -67,6 +75,10 @@ namespace Hyena
 
         public SafeUri (Uri uri)
         {
+            if (uri == null) {
+                throw new ArgumentNullException ("uri");
+            }
+
             this.uri = uri.AbsoluteUri;
         }