Fix ResponseUri returning original URL instead of redirect target when FollowRedirects=false (#2346) (#2350)

When FollowRedirects is disabled and the server returns a 3xx redirect,
ResponseUri now returns the Location header value (the redirect target)
instead of the original request URL. Non-redirect responses are unaffected.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: alexeyzimarev

src/RestSharp/Response/RestResponse.cs

@@ -68,7 +68,7 @@ async Task<RestResponse> GetDefaultResponse() {
                 IsSuccessStatusCode = httpResponse.IsSuccessStatusCode,
                 RawBytes            = bytes,
                 ResponseStatus      = options.CalculateResponseStatus(httpResponse),
-                ResponseUri         = httpResponse.RequestMessage?.RequestUri,
+                ResponseUri         = GetResponseUri(httpResponse),
                 RootElement         = request.RootElement,
                 Server              = httpResponse.Headers.Server.ToString(),
                 StatusCode          = httpResponse.StatusCode,
@@ -79,6 +79,19 @@ async Task<RestResponse> GetDefaultResponse() {
     }
 
     public RestResponse() : this(new()) { }
+
+    static Uri? GetResponseUri(HttpResponseMessage httpResponse) {
+        var requestUri = httpResponse.RequestMessage?.RequestUri;
+
+        if ((int)httpResponse.StatusCode is >= 300 and < 400
+            && httpResponse.Headers.Location is { } location) {
+            return location.IsAbsoluteUri || requestUri == null
+                ? location
+                : new Uri(requestUri, location);
+        }
+
+        return requestUri;
+    }
 }
 
 public delegate ResponseStatus CalculateResponseStatus(HttpResponseMessage httpResponse);

test/RestSharp.Tests.Integrated/RedirectTests.cs

@@ -14,5 +14,24 @@ public async Task Can_Perform_GET_Async_With_Redirect() {
         response.Data!.Message.Should().Be(val);
     }
 
+    [Fact]
+    public async Task ResponseUri_Should_Be_Final_Url_When_FollowRedirects_True() {
+        var request  = new RestRequest("redirect");
+        var response = await _client.ExecuteAsync(request);
+
+        response.ResponseUri.Should().Be(new Uri(new Uri(server.Url!), "success"));
+    }
+
+    [Fact]
+    public async Task ResponseUri_Should_Be_Redirect_Target_When_FollowRedirects_False() {
+        using var client = new RestClient(new RestClientOptions(server.Url!) { FollowRedirects = false });
+
+        var request  = new RestRequest("redirect");
+        var response = await client.ExecuteAsync(request);
+
+        response.StatusCode.Should().Be(HttpStatusCode.Redirect);
+        response.ResponseUri.Should().Be(new Uri(new Uri(server.Url!), "success"));
+    }
+
     public void Dispose() => _client.Dispose();
 }