Updated URL rewriter to handle torcache Referer weirdness.

src/NzbDrone.Core.Test/Http/TorCacheHttpRequestInterceptorFixture.cs

@@ -23,6 +23,16 @@ namespace NzbDrone.Core.Test.Http
             newRequest.Url.AbsoluteUri.Should().Be("http://torcache.net/download/123.torrent");
         }
 
+        [Test]
+        public void should_add_referrer_torcache_request()
+        {
+            var request = new HttpRequest("http://torcache.net/download/123.torrent?title=something");
+
+            var newRequest = Subject.PreRequest(request);
+
+            newRequest.Headers.Should().Contain("Referer", "http://torcache.net/");
+        }
+
         [TestCase("http://site.com/download?url=torcache.net&blaat=1")]
         [TestCase("http://torcache.net.com/download?url=123")]
         public void should_not_remove_query_params_from_other_requests(string url)

src/NzbDrone.Core/Http/TorcacheHttpInterceptor.cs

@@ -11,9 +11,12 @@ namespace NzbDrone.Core.Http
     {
         public HttpRequest PreRequest(HttpRequest request)
         {
-            if (request.Url.Host == "torcache.net" && request.UriBuilder.Query.IsNotNullOrWhiteSpace())
+            // torcache behaves strangely when it has query params and/or no Referer or browser User-Agent.
+            // It's a bit vague, and we don't need the query params. So we remove the query params and set a Referer to be safe.
+            if (request.Url.Host == "torcache.net")
             {
                 request.UriBuilder.Query = string.Empty;
+                request.Headers.Add("Referer", request.Url.Scheme + @"://torcache.net/");
             }
 
             return request;