Fixes for less-common HTTP responses that lack some headers.

2 files changed, 6 insertions, 2 deletions

diff --git a/src/DotNetOpenAuth/Yadis/DiscoveryResult.cs b/src/DotNetOpenAuth/Yadis/DiscoveryResult.cs
index 90495e2..01dae40 100644
--- a/src/DotNetOpenAuth/Yadis/DiscoveryResult.cs
+++ b/src/DotNetOpenAuth/Yadis/DiscoveryResult.cs
@@ -28,7 +28,7 @@ namespace DotNetOpenAuth.Yadis {
 			if (finalResponse == null) {
 				this.ContentType = initialResponse.ContentType;
 				this.ResponseText = initialResponse.GetResponseString();
-				this.IsXrds = ContentType.MediaType == ContentTypes.Xrds;
+				this.IsXrds = this.ContentType != null && this.ContentType.MediaType == ContentTypes.Xrds;
 			} else {
 				this.ContentType = finalResponse.ContentType;
 				this.ResponseText = finalResponse.GetResponseString();
diff --git a/src/DotNetOpenAuth/Yadis/Yadis.cs b/src/DotNetOpenAuth/Yadis/Yadis.cs
index c3ae307..98bffc9 100644
--- a/src/DotNetOpenAuth/Yadis/Yadis.cs
+++ b/src/DotNetOpenAuth/Yadis/Yadis.cs
@@ -76,7 +76,7 @@ namespace DotNetOpenAuth.Yadis {
 						Logger.Yadis.DebugFormat("{0} found in HTTP header.  Preparing to pull XRDS from {1}", HeaderName, url);
 					}
 				}
-				if (url == null && response.ContentType.MediaType == ContentTypes.Html) {
+				if (url == null && response.ContentType != null && response.ContentType.MediaType == ContentTypes.Html) {
 					url = FindYadisDocumentLocationInHtmlMetaTags(response.GetResponseString());
 					if (url != null) {
 						Logger.Yadis.DebugFormat("{0} found in HTML Http-Equiv tag.  Preparing to pull XRDS from {1}", HeaderName, url);
@@ -152,6 +152,10 @@ namespace DotNetOpenAuth.Yadis {
 		/// 	<c>true</c> if the response constains an XRDS document; otherwise, <c>false</c>.
 		/// </returns>
 		private static bool IsXrdsDocument(CachedDirectWebResponse response) {
+			if (response.ContentType == null) {
+				return false;
+			}
+
 			if (response.ContentType.MediaType == ContentTypes.Xrds) {
 				return true;
 			}