From d56f3ec2e774fb9f54a498afcba4b6bd89d1cc8f Mon Sep 17 00:00:00 2001
From: Qstick <qstick@gmail.com>
Date: Sat, 12 Jun 2021 16:24:48 -0400
Subject: [PATCH] Fixed: Correctly handle 302 and 303 redirects in HttpClient

(cherry picked from commit ed7c5a937f4b50fcdf819e8fe347c8c0bc6bd2e7)

(cherry picked from commit 11bd764a75d3b97117098738d3489c4b3329738f)
---
 src/NzbDrone.Common/Http/HttpClient.cs | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/src/NzbDrone.Common/Http/HttpClient.cs b/src/NzbDrone.Common/Http/HttpClient.cs
index 175448e43..2824a8f94 100644
--- a/src/NzbDrone.Common/Http/HttpClient.cs
+++ b/src/NzbDrone.Common/Http/HttpClient.cs
@@ -60,8 +60,7 @@ namespace NzbDrone.Common.Http
 
             if (request.AllowAutoRedirect && response.HasHttpRedirect)
             {
-                var autoRedirectChain = new List<string>();
-                autoRedirectChain.Add(request.Url.ToString());
+                var autoRedirectChain = new List<string> { request.Url.ToString() };
 
                 do
                 {
@@ -75,6 +74,14 @@ namespace NzbDrone.Common.Http
                         throw new WebException($"Too many automatic redirections were attempted for {autoRedirectChain.Join(" -> ")}", WebExceptionStatus.ProtocolError);
                     }
 
+                    // 302 or 303 should default to GET on redirect even if POST on original
+                    if (RequestRequiresForceGet(response.StatusCode, response.Request.Method))
+                    {
+                        request.Method = HttpMethod.Get;
+                        request.ContentData = null;
+                        request.ContentSummary = null;
+                    }
+
                     response = ExecuteRequest(request, cookieContainer);
                 }
                 while (response.HasHttpRedirect);
@@ -105,6 +112,16 @@ namespace NzbDrone.Common.Http
             return response;
         }
 
+        private static bool RequestRequiresForceGet(HttpStatusCode statusCode, HttpMethod requestMethod)
+        {
+            return statusCode switch
+            {
+                HttpStatusCode.Moved or HttpStatusCode.Found or HttpStatusCode.MultipleChoices => requestMethod == HttpMethod.Post,
+                HttpStatusCode.SeeOther => requestMethod != HttpMethod.Get && requestMethod != HttpMethod.Head,
+                _ => false,
+            };
+        }
+
         private HttpResponse ExecuteRequest(HttpRequest request, CookieContainer cookieContainer)
         {
             foreach (var interceptor in _requestInterceptors)