Use HttpRequestError.Unknown for the rest

Author: MihaZupan

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs

@@ -2205,7 +2205,7 @@ internal void Trace(int streamId, string message, [CallerMemberName] string? mem
 
         [DoesNotReturn]
         private static void ThrowRetry(string message, Exception? innerException = null) =>
-            throw new HttpRequestException(message, innerException, allowRetry: RequestRetryType.RetryOnConnectionFailure);
+            throw new HttpRequestException(HttpRequestError.Unknown, message, innerException, RequestRetryType.RetryOnConnectionFailure);
 
         private static Exception GetRequestAbortedException(Exception? innerException = null) =>
             innerException as HttpIOException ?? new IOException(SR.net_http_request_aborted, innerException);

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http3Connection.cs

@@ -208,7 +208,7 @@ public async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, lon
 
                 if (quicStream == null)
                 {
-                    throw new HttpRequestException(SR.net_http_request_aborted, null, RequestRetryType.RetryOnConnectionFailure);
+                    throw new HttpRequestException(HttpRequestError.Unknown, SR.net_http_request_aborted, null, RequestRetryType.RetryOnConnectionFailure);
                 }
 
                 requestStream!.StreamId = quicStream.Id;
@@ -221,7 +221,7 @@ public async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, lon
 
                 if (goAway)
                 {
-                    throw new HttpRequestException(SR.net_http_request_aborted, null, RequestRetryType.RetryOnConnectionFailure);
+                    throw new HttpRequestException(HttpRequestError.Unknown, SR.net_http_request_aborted, null, RequestRetryType.RetryOnConnectionFailure);
                 }
 
                 if (NetEventSource.Log.IsEnabled()) Trace($"Sending request: {request}");
@@ -237,7 +237,7 @@ public async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, lon
             {
                 // This will happen if we aborted _connection somewhere and we have pending OpenOutboundStreamAsync call.
                 // note that _abortException may be null if we closed the connection in response to a GOAWAY frame
-                throw new HttpRequestException(SR.net_http_client_execution_error, _abortException, RequestRetryType.RetryOnConnectionFailure);
+                throw new HttpRequestException(HttpRequestError.Unknown, SR.net_http_client_execution_error, _abortException, RequestRetryType.RetryOnConnectionFailure);
             }
             finally
             {

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http3RequestStream.cs

@@ -252,7 +252,7 @@ await Task.WhenAny(sendContentTask, readResponseTask).ConfigureAwait(false) == s
                 {
                     case Http3ErrorCode.VersionFallback:
                         // The server is requesting us fall back to an older HTTP version.
-                        throw new HttpRequestException(SR.net_http_retry_on_older_version, ex, RequestRetryType.RetryOnLowerHttpVersion);
+                        throw new HttpRequestException(HttpRequestError.Unknown, SR.net_http_retry_on_older_version, ex, RequestRetryType.RetryOnLowerHttpVersion);
 
                     case Http3ErrorCode.RequestRejected:
                         // The server is rejecting the request without processing it, retry it on a different connection.

src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/HttpConnection.cs

@@ -882,19 +882,23 @@ private bool MapSendException(Exception exception, CancellationToken cancellatio
                 mappedException = CancellationHelper.CreateOperationCanceledException(exception, cancellationToken);
                 return true;
             }
+
             if (exception is InvalidOperationException)
             {
                 // For consistency with other handlers we wrap the exception in an HttpRequestException.
                 mappedException = new HttpRequestException(SR.net_http_client_execution_error, exception);
                 return true;
             }
+
             if (exception is IOException ioe)
             {
                 // For consistency with other handlers we wrap the exception in an HttpRequestException.
                 // If the request is retryable, indicate that on the exception.
-                mappedException = new HttpRequestException(SR.net_http_client_execution_error, ioe, _canRetry ? RequestRetryType.RetryOnConnectionFailure : RequestRetryType.NoRetry);
+                HttpRequestError error = ioe is HttpIOException httpIoe ? httpIoe.HttpRequestError : HttpRequestError.Unknown;
+                mappedException = new HttpRequestException(error, SR.net_http_client_execution_error, ioe, _canRetry ? RequestRetryType.RetryOnConnectionFailure : RequestRetryType.NoRetry);
                 return true;
             }
+
             // Otherwise, just allow the original exception to propagate.
             mappedException = exception;
             return false;