The PR resolves an issue reported under #132.

Use existing query parameter string from blobstore response and then append digest.  Test updated to ensure existing query parameters are maintained

Signed-off-by: Daniel Robinson <[email protected]>

src/OrasProject.Oras/Registry/Remote/BlobStore.cs

@@ -152,7 +152,7 @@ public async Task PushAsync(Descriptor expected, Stream content, CancellationTok
         // add digest key to query string with expected digest value
         var req = new HttpRequestMessage(HttpMethod.Put, new UriBuilder(url)
         {
-            Query = $"digest={HttpUtility.UrlEncode(expected.Digest)}"
+            Query = $"{url.Query}&digest={HttpUtility.UrlEncode(expected.Digest)}"
         }.Uri);
         req.Content = new StreamContent(content);
         req.Content.Headers.ContentLength = expected.Size;

tests/OrasProject.Oras.Tests/Remote/RepositoryTest.cs

@@ -1082,19 +1082,25 @@ public async Task BlobStore_PushAsync()
         };
         var gotBlob = new byte[blob.Length];
         var uuid = Guid.NewGuid().ToString();
+        var existingQueryParameter = "existingParam=value";
+
         var func = (HttpRequestMessage req, CancellationToken cancellationToken) =>
         {
             var res = new HttpResponseMessage();
             res.RequestMessage = req;
             if (req.Method == HttpMethod.Post && req.RequestUri?.AbsolutePath == $"/v2/test/blobs/uploads/")
             {
                 res.StatusCode = HttpStatusCode.Accepted;
-                res.Headers.Add("Location", "/v2/test/blobs/uploads/" + uuid);
+                res.Headers.Add("Location", $"/v2/test/blobs/uploads/{uuid}?{existingQueryParameter}");
                 return res;
             }
 
             if (req.Method == HttpMethod.Put && req.RequestUri?.AbsolutePath == "/v2/test/blobs/uploads/" + uuid)
             {
+                // Assert that the existing query parameter is present
+                var queryParameters = HttpUtility.ParseQueryString(req.RequestUri.Query);
+                Assert.Equal("value", queryParameters["existingParam"]);
+
                 if (req.Headers.TryGetValues("Content-Type", out var contentType) &&
                     contentType.FirstOrDefault() != "application/octet-stream")
                 {