Don't sanitize the keys for Filters aggregation named buckets #4656

This commit fixes a bug where the keys in the dictionary passed
to filters aggregation are sanitized when copying to the backing
dictionary. Keys in this scenario are the keys for named buckets
which should never be sanitized.

Fixes #4582

Author: russcam

src/Nest/Aggregations/Bucket/Filters/FiltersAggregate.cs

@@ -10,7 +10,7 @@ public FiltersBucketItem(IReadOnlyDictionary<string, IAggregate> dict) : base(di
 		public long DocCount { get; set; }
 	}
 
-	//TODO this is mapped rather odly we always deserialize as if this is
+	//TODO this is mapped rather oddly we always deserialize as if this is
 	// {
 	//    "agg1" : { ...},
 	//	  "agg2" : { ... }
@@ -27,6 +27,9 @@ public FiltersAggregate() : base(EmptyReadOnly<string, IAggregate>.Dictionary) {
 
 		public FiltersAggregate(IReadOnlyDictionary<string, IAggregate> aggregations) : base(aggregations) { }
 
+		// Don't sanitize the keys as these are the keys for named buckets
+        protected override string Sanitize(string key) => key;
+
 		public IReadOnlyCollection<FiltersBucketItem> Buckets { get; set; } = EmptyReadOnly<FiltersBucketItem>.Collection;
 
 		public SingleBucketAggregate NamedBucket(string key) => Global(key);

src/Tests/Reproduce/GithubIssue3286.cs renamed to src/Tests/Tests.Reproduce/GithubIssue3286.cs

@@ -5,18 +5,15 @@
 using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
-using Tests.Framework.ManagedElasticsearch.Clusters;
+using Tests.Core.ManagedElasticsearch.Clusters;
 
 namespace Tests.Reproduce
 {
 	public class GithubIssue3286 : IClusterFixture<WritableCluster>
 	{
 		private readonly WritableCluster _cluster;
 
-		public GithubIssue3286(WritableCluster cluster)
-		{
-			_cluster = cluster;
-		}
+		public GithubIssue3286(WritableCluster cluster) => _cluster = cluster;
 
 		[I]
 		public void AggregationsShouldNotBeNullOnNestedAggregation()

src/Tests/Reproduce/GithubIssue3311.cs renamed to src/Tests/Tests.Reproduce/GithubIssue3311.cs

@@ -1,11 +1,9 @@
 using System;
-using System.Collections.Generic;
 using System.Linq;
 using Elastic.Xunit.XunitPlumbing;
-using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
-using Tests.Framework.ManagedElasticsearch.Clusters;
+using Tests.Core.ManagedElasticsearch.Clusters;
 
 namespace Tests.Reproduce
 {

src/Tests/Tests.Reproduce/GithubIssue4582.cs

@@ -0,0 +1,53 @@
+using System;
+using System.Linq;
+using System.Text;
+using Elastic.Xunit.XunitPlumbing;
+using Elasticsearch.Net;
+using FluentAssertions;
+using Nest;
+
+namespace Tests.Reproduce
+{
+	public class GithubIssue4582
+	{
+		[U]
+		public void DeserializeBucketKeyWithHash()
+		{
+			var json = @"
+{
+  ""hits"": {
+  },
+  ""aggregations"":
+  {
+    ""some_agg"" : {
+      ""buckets"" : {
+        ""value1"" : {
+          ""doc_count"" : 0
+        },
+        ""value2"" : {
+          ""doc_count"" : 0
+        },
+        ""value3#something else"" : {
+          ""doc_count"" : 0
+        }
+      }
+    }
+  }
+}
+";
+
+			var bytes = Encoding.UTF8.GetBytes(json);
+			var pool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));
+			var connectionSettings = new ConnectionSettings(pool, new InMemoryConnection(bytes));
+			var client = new ElasticClient(connectionSettings);
+			var response = client.Search<object>(s => s.Index("index"));
+
+			var filters = response.Aggregations
+				.Filters("some_agg")
+				.Select(x => x.Key)
+				.ToList();
+
+			filters[2].Should().Be("value3#something else");
+		}
+	}
+}