Fixed: http->https redirects do not use the tls1.2 curl fallback.

fixes #2082

src/NzbDrone.Common.Test/Http/HttpClientFixture.cs

@@ -144,6 +144,33 @@ namespace NzbDrone.Common.Test.Http
             ExceptionVerification.ExpectedErrors(0);
         }
 
+        [Test]
+        public void should_follow_redirects_to_https()
+        {
+            var request = new HttpRequestBuilder($"http://{_httpBinHost}/redirect-to")
+                .AddQueryParam("url", $"https://sonarr.tv/")
+                .Build();
+            request.AllowAutoRedirect = true;
+
+            var response = Subject.Get(request);
+
+            response.StatusCode.Should().Be(HttpStatusCode.OK);
+            response.Content.Should().Contain("Sonarr");
+
+            ExceptionVerification.ExpectedErrors(0);
+        }
+
+        [Test]
+        public void should_throw_on_too_many_redirects()
+        {
+            var request = new HttpRequest($"http://{_httpBinHost}/redirect/4");
+            request.AllowAutoRedirect = true;
+
+            Assert.Throws<WebException>(() => Subject.Get(request));
+
+            ExceptionVerification.ExpectedErrors(0);
+        }
+
         [Test]
         public void should_send_user_agent()
         {

src/NzbDrone.Common/Http/Dispatchers/CurlHttpDispatcher.cs

@@ -107,7 +107,7 @@ namespace NzbDrone.Common.Http.Dispatchers
                             throw new NotSupportedException($"HttpCurl method {request.Method} not supported");
                     }
                     curlEasy.UserAgent = _userAgentBuilder.GetUserAgent(request.UseSimplifiedUserAgent);
-                    curlEasy.FollowLocation = request.AllowAutoRedirect;
+                    curlEasy.FollowLocation = false;
 
                     if (request.RequestTimeout != TimeSpan.Zero)
                     {

src/NzbDrone.Common/Http/Dispatchers/ManagedHttpDispatcher.cs

@@ -32,7 +32,7 @@ namespace NzbDrone.Common.Http.Dispatchers
             webRequest.Method = request.Method.ToString();
             webRequest.UserAgent = _userAgentBuilder.GetUserAgent(request.UseSimplifiedUserAgent);
             webRequest.KeepAlive = request.ConnectionKeepAlive;
-            webRequest.AllowAutoRedirect = request.AllowAutoRedirect;
+            webRequest.AllowAutoRedirect = false;
             webRequest.CookieContainer = cookies;
 
             if (request.RequestTimeout != TimeSpan.Zero)

src/NzbDrone.Common/Http/HttpClient.cs

@@ -7,6 +7,7 @@ using System.Net;
 using NLog;
 using NzbDrone.Common.Cache;
 using NzbDrone.Common.EnvironmentInfo;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Common.Http.Dispatchers;
 using NzbDrone.Common.TPL;
 
@@ -50,6 +51,57 @@ namespace NzbDrone.Common.Http
         }
 
         public HttpResponse Execute(HttpRequest request)
+        {
+            var autoRedirectCount = 0;
+            var autoRedirectChain = new List<string>();
+            autoRedirectChain.Add(request.Url.ToString());
+
+            var response = ExecuteRequest(request);
+
+            while (response.StatusCode == HttpStatusCode.Moved ||
+                   response.StatusCode == HttpStatusCode.MovedPermanently ||
+                   response.StatusCode == HttpStatusCode.Found)
+            {
+                if (request.AllowAutoRedirect)
+                {
+                    request.Url += new HttpUri(response.Headers.GetSingleValue("Location"));
+                    autoRedirectChain.Add(request.Url.ToString());
+
+                    _logger.Trace("Redirected to {0}", request.Url);
+
+                    autoRedirectCount++;
+                    if (autoRedirectCount > 3)
+                    {
+                        throw new WebException($"Too many automatic redirections were attempted for {autoRedirectChain.Join(" -> ")}", WebExceptionStatus.ProtocolError);
+                    }
+
+                    response = ExecuteRequest(request);
+                }
+                else if (!RuntimeInfo.IsProduction)
+                {
+                    _logger.Error("Server requested a redirect to [{0}]. Update the request URL to avoid this redirect.", response.Headers["Location"]);
+                    break;
+                }
+            }
+
+            if (!request.SuppressHttpError && response.HasHttpError)
+            {
+                _logger.Warn("HTTP Error - {0}", response);
+
+                if ((int)response.StatusCode == 429)
+                {
+                    throw new TooManyRequestsException(request, response);
+                }
+                else
+                {
+                    throw new HttpException(request, response);
+                }
+            }
+
+            return response;
+        }
+
+        private HttpResponse ExecuteRequest(HttpRequest request)
         {
             foreach (var interceptor in _requestInterceptors)
             {
@@ -85,28 +137,6 @@ namespace NzbDrone.Common.Http
                 _logger.Trace("Response content ({0} bytes): {1}", response.ResponseData.Length, response.Content);
             }
 
-            if (!RuntimeInfo.IsProduction &&
-                (response.StatusCode == HttpStatusCode.Moved ||
-                 response.StatusCode == HttpStatusCode.MovedPermanently ||
-                 response.StatusCode == HttpStatusCode.Found))
-            {
-                _logger.Error("Server requested a redirect to [{0}]. Update the request URL to avoid this redirect.", response.Headers["Location"]);
-            }
-
-            if (!request.SuppressHttpError && response.HasHttpError)
-            {
-                _logger.Warn("HTTP Error - {0}", response);
-
-                if ((int)response.StatusCode == 429)
-                {
-                    throw new TooManyRequestsException(request, response);
-                }
-                else
-                {
-                    throw new HttpException(request, response);
-                }
-            }
-
             return response;
         }