Merge pull request #4212 from BaronGreenback/BaseControlHandlerFix

Null Pointer fix: BaseControlHandler.cs

Emby.Dlna/Server/DescriptionXmlBuilder.cs

@@ -235,13 +235,13 @@ namespace Emby.Dlna.Server
                     .Append(SecurityElement.Escape(service.ServiceId ?? string.Empty))
                     .Append("</serviceId>");
                 builder.Append("<SCPDURL>")
-                    .Append(BuildUrl(service.ScpdUrl, true))
+                    .Append(BuildUrl(service.ScpdUrl))
                     .Append("</SCPDURL>");
                 builder.Append("<controlURL>")
-                    .Append(BuildUrl(service.ControlUrl, true))
+                    .Append(BuildUrl(service.ControlUrl))
                     .Append("</controlURL>");
                 builder.Append("<eventSubURL>")
-                    .Append(BuildUrl(service.EventSubUrl, true))
+                    .Append(BuildUrl(service.EventSubUrl))
                     .Append("</eventSubURL>");
 
                 builder.Append("</service>");
@@ -250,13 +250,7 @@ namespace Emby.Dlna.Server
             builder.Append("</serviceList>");
         }
 
-        /// <summary>
+        private string BuildUrl(string url)
-        /// Builds a valid url for inclusion in the xml.
-        /// </summary>
-        /// <param name="url">Url to include.</param>
-        /// <param name="absoluteUrl">Optional. When set to true, the absolute url is always used.</param>
-        /// <returns>The url to use for the element.</returns>
-        private string BuildUrl(string url, bool absoluteUrl = false)
         {
             if (string.IsNullOrEmpty(url))
             {
@@ -267,7 +261,7 @@ namespace Emby.Dlna.Server
 
             url = "/dlna/" + _serverUdn + "/" + url;
 
-            if (EnableAbsoluteUrls || absoluteUrl)
+            if (EnableAbsoluteUrls)
             {
                 url = _serverAddress.TrimEnd('/') + url;
             }

Emby.Dlna/Service/BaseControlHandler.cs

@@ -150,12 +150,12 @@ namespace Emby.Dlna.Service
                 }
             }
 
-            return new ControlRequestInfo();
+            throw new EndOfStreamException("Stream ended but no body tag found.");
         }
 
         private async Task<ControlRequestInfo> ParseBodyTagAsync(XmlReader reader)
         {
-            var result = new ControlRequestInfo();
+            string namespaceURI = null, localName = null;
 
             await reader.MoveToContentAsync().ConfigureAwait(false);
             await reader.ReadAsync().ConfigureAwait(false);
@@ -165,11 +165,12 @@ namespace Emby.Dlna.Service
             {
                 if (reader.NodeType == XmlNodeType.Element)
                 {
-                    result.LocalName = reader.LocalName;
+                    localName = reader.LocalName;
-                    result.NamespaceURI = reader.NamespaceURI;
+                    namespaceURI = reader.NamespaceURI;
 
                     if (!reader.IsEmptyElement)
                     {
+                        var result = new ControlRequestInfo(localName, namespaceURI);
                         using (var subReader = reader.ReadSubtree())
                         {
                             await ParseFirstBodyChildAsync(subReader, result.Headers).ConfigureAwait(false);
@@ -187,7 +188,12 @@ namespace Emby.Dlna.Service
                 }
             }
 
-            return result;
+            if (localName != null && namespaceURI != null)
+            {
+                return new ControlRequestInfo(localName, namespaceURI);
+            }
+
+            throw new EndOfStreamException("Stream ended but no control found.");
         }
 
         private async Task ParseFirstBodyChildAsync(XmlReader reader, IDictionary<string, string> headers)
@@ -234,11 +240,18 @@ namespace Emby.Dlna.Service
 
         private class ControlRequestInfo
         {
+            public ControlRequestInfo(string localName, string namespaceUri)
+            {
+                LocalName = localName;
+                NamespaceURI = namespaceUri;
+                Headers = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            }
+
             public string LocalName { get; set; }
 
             public string NamespaceURI { get; set; }
 
-            public Dictionary<string, string> Headers { get; } = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+            public Dictionary<string, string> Headers { get; }
         }
     }
 }