Exception caused by automatic redirection resulting in the destructio…

src/Flurl.Http/Flurl.Http.csproj

@@ -3,7 +3,7 @@
     <TargetFrameworks>netstandard2.0;net461;net472</TargetFrameworks>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
     <PackageId>Flurl.Http</PackageId>
-    <Version>3.2.4</Version>
+    <Version>3.2.5</Version>
     <Authors>Todd Menier</Authors>
     <Description>A fluent, portable, testable HTTP client library.</Description>
     <PackageProjectUrl>https://flurl.dev</PackageProjectUrl>

src/Flurl.Http/FlurlRequest.cs

@@ -180,13 +180,14 @@ public async Task<IFlurlResponse> SendAsync(HttpMethod verb, HttpContent content
 			var ct = GetCancellationTokenWithTimeout(cancellationToken, out var cts);
 
 			try {
+				var cloneContent = await content.CloneAsync().ConfigureAwait(false);
 				var response = await Client.HttpClient.SendAsync(request, completionOption, ct).ConfigureAwait(false);
 				call.HttpResponseMessage = response;
 				call.HttpResponseMessage.RequestMessage = request;
 				call.Response = new FlurlResponse(call.HttpResponseMessage, CookieJar);
 
 				if (call.Succeeded) {
-					var redirResponse = await ProcessRedirectAsync(call, cancellationToken, completionOption).ConfigureAwait(false);
+					var redirResponse = await ProcessRedirectAsync(call, cloneContent, cancellationToken, completionOption).ConfigureAwait(false);
 					return redirResponse ?? call.Response;
 				}
 				else
@@ -231,7 +232,7 @@ private CancellationToken GetCancellationTokenWithTimeout(CancellationToken orig
 			}
 		}
 
-		private async Task<IFlurlResponse> ProcessRedirectAsync(FlurlCall call, CancellationToken cancellationToken, HttpCompletionOption completionOption) {
+		private async Task<IFlurlResponse> ProcessRedirectAsync(FlurlCall call, HttpContent content, CancellationToken cancellationToken, HttpCompletionOption completionOption) {
 			if (Settings.Redirects.Enabled)
 				call.Redirect = GetRedirect(call);
 
@@ -266,7 +267,7 @@ private async Task<IFlurlResponse> ProcessRedirectAsync(FlurlCall call, Cancella
 			try {
 				return await redir.SendAsync(
 					changeToGet ? HttpMethod.Get : call.HttpRequestMessage.Method,
-					changeToGet ? null : call.HttpRequestMessage.Content,
+					changeToGet ? null : content,
 					ct,
 					completionOption).ConfigureAwait(false);
 			}

src/Flurl.Http/HttpContentExtensions.cs

@@ -0,0 +1,38 @@
+using System.IO;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Flurl.Http
+{
+	/// <summary>
+	/// Extension methods of HttpContent
+	/// </summary>
+	public static class HttpContentExtensions
+	{
+		/// <summary>Get a copy of the request content.</summary>
+		/// <param name="content">The content to copy.</param>
+		/// <param name="cancellationToken">The cancellation token.</param>
+		/// <remarks>Note that cloning content isn't possible after it's dispatched, because the stream is automatically disposed after the request.</remarks>
+		internal static async Task<HttpContent> CloneAsync(this HttpContent content, CancellationToken cancellationToken = default) {
+			if (content == null)
+				return null;
+
+			Stream stream = new MemoryStream();
+			await content
+				.CopyToAsync(stream
+#if NET5_0_OR_GREATER
+					, cancellationToken
+#endif
+				)
+				.ConfigureAwait(false);
+			stream.Position = 0;
+
+			StreamContent clone = new StreamContent(stream);
+			foreach (var header in content.Headers)
+				clone.Headers.Add(header.Key, header.Value);
+
+			return clone;
+		}
+	}
+}