Revert MultiplexingMiddleware

Author: raman-m

src/Ocelot/Multiplexer/MultiplexingMiddleware.cs

@@ -166,14 +166,11 @@ private IEnumerable<Task<HttpContext>> ProcessRouteWithComplexAggregation(Aggreg
         JToken jObject, HttpContext httpContext, DownstreamRoute downstreamRoute)
     {
         var processing = new List<Task<HttpContext>>();
-        var values = jObject.SelectTokens(matchAdvancedAgg.JsonPath).Select(s => s.ToString()).Distinct()
-            .ToList();
+        var values = jObject.SelectTokens(matchAdvancedAgg.JsonPath).Select(s => s.ToString()).Distinct();
         foreach (var value in values)
         {
-            var tPnv = new List<PlaceholderNameAndValue>(httpContext.Items.TemplatePlaceholderNameAndValues())
-            {
-                new('{' + matchAdvancedAgg.Parameter + '}', value),
-            };
+            var tPnv = httpContext.Items.TemplatePlaceholderNameAndValues();
+            tPnv.Add(new PlaceholderNameAndValue('{' + matchAdvancedAgg.Parameter + '}', value));
             processing.Add(ProcessRouteAsync(httpContext, downstreamRoute, tPnv));
         }
 
@@ -258,16 +255,6 @@ protected virtual Task MapAsync(HttpContext httpContext, Route route, List<HttpC
             return Task.CompletedTask;
         }
 
-        // ensure each context retains its correct aggregate key for proper response mapping
-        if (route.DownstreamRouteConfig != null && route.DownstreamRouteConfig.Count > 0)
-        {
-            for (int i = 0; i < contexts.Count && i < route.DownstreamRouteConfig.Count; i++)
-            {
-                var key = route.DownstreamRouteConfig[i].RouteKey;
-                contexts[i].Items["CurrentAggregateRouteKey"] = key;
-            }
-        }
-
         var aggregator = _factory.Get(route);
         return aggregator.Aggregate(route, httpContext, contexts);
     }