Remove comment only ProductInfoHeaderValue

Version

all, but particularly 4.11.+

Describe the bug

In 4.11, we have added a constructor to ConnectorClient which takes an HttpClient. We then pass that HttpClient down to the underlying ServicClient’s constructor. Due to the fact that we have a ProductInfoHeaderValue which has no Product (comment only), the underlying ServiceClient will throw and catch 4 exceptions.

I’ve created a PR to address this within ServiceClient, but they have recommended we remove the comment only ProductInfoHeaderValue: https://github.com/Azure/azure-sdk-for-net/pull/16252

To Reproduce

Steps to reproduce the behavior: Run this test:

        [Fact]
        public void ConnectorClient_CustomHttpClient_UserAgentHeaderAdds()
        {
            var httpClient = new HttpClient();
            ConnectorClient.AddDefaultRequestHeaders(httpClient);

            using (var connector = new ConnectorClient(new Uri("http://localhost/"), new MicrosoftAppCredentials(string.Empty, string.Empty), customHttpClient: httpClient, disposeHttpClient: false))
            {
                // Use the connector
            }

            Assert.Equal(6, httpClient.DefaultRequestHeaders.UserAgent.Count);
        }

Notice, none of the ServiceClient UserAgent headers have been added.

Expected behavior

Underlying ServiceClient UserAgent headers are added.

Remove the comment only product info header, and re-run the above test. It will pass. https://github.com/microsoft/botbuilder-dotnet/blob/main/libraries/Microsoft.Bot.Connector/ConnectorClientEx.cs#L200

[EricDahlvang]

The recommendation for anyone seeing a null reference exception due to this is to ignore.

[EricDahlvang]

Hi @sebnema

I’m sorry you’ve spent time investigating this. The root cause is a known issue. You are correct, that the problem is in ServiceClient and has been present for years now. They are apprehensive to take a fix at this level of the core product: https://github.com/Azure/azure-sdk-for-net/pull/16252

The reason the Bot Builder sdk has not had this issue until 4.11.0 is because we were not using the ServiceClient constructor with HttpClient param, until 4.11.0: https://github.com/microsoft/botbuilder-dotnet/commit/918c54778e0c0e48187560661f208e034ceffb31#diff-914b91edd6e7e20fb74559dea5488a0b0ee7d63a197cd703135fb1adf44d079a

Our plan to resolve this in 4.12.0 is to replace the comment only ProductInfoHeaderValue in the Bot Builder SDK with one containing a product.