fix #907 using untyped SearchRequest() should still infer default index

Author: Mpdreamz

Diff for: src/Nest/DSL/Paths/QueryPathDescriptor.cs

@@ -38,6 +38,8 @@ public static void SetRouteParameters<TParameters>(
 				pathInfo.Index = inferrer.IndexNames(path.Indices);
 			else if (path.AllIndices.GetValueOrDefault(false) && !pathInfo.Type.IsNullOrEmpty())
 				pathInfo.Index = "_all";
+			else if (!path.AllIndices.GetValueOrDefault(false) && pathInfo.Index.IsNullOrEmpty())
+				pathInfo.Index = inferrer.DefaultIndex;
 
 		}
 		public static void SetRouteParameters<TParameters, T>(

Diff for: src/Tests/Nest.Tests.Unit/Nest.Tests.Unit.csproj

@@ -235,6 +235,7 @@
     <Compile Include="ObjectInitializer\Aliases\GetAliasesRequestTests.cs" />
     <Compile Include="ObjectInitializer\Aliases\AliasRequestTests.cs" />
     <Compile Include="ObjectInitializer\Nodes\NodesHotThreadsRequestTests.cs" />
+    <Compile Include="ObjectInitializer\Search\SearchRequestUntypedTests.cs" />
     <Compile Include="ObjectInitializer\Status\StatusRequestTests.cs" />
     <Compile Include="ObjectInitializer\IndicesStats\IndicesStatsRequestTests.cs" />
     <Compile Include="ObjectInitializer\ClusterState\ClusterStateRequestTests.cs" />

Diff for: src/Tests/Nest.Tests.Unit/ObjectInitializer/Search/SearchRequestUntypedTests.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using Elasticsearch.Net;
+using FluentAssertions;
+using Nest.Resolvers;
+using Nest.Tests.MockData.Domain;
+using NUnit.Framework;
+
+namespace Nest.Tests.Unit.ObjectInitializer.Search
+{
+	[TestFixture]
+	public class SearchRequestUntypedTests : BaseJsonTests
+	{
+		private readonly IElasticsearchResponse _status;
+
+		public SearchRequestUntypedTests()
+		{
+			QueryContainer query = new TermQuery()
+			{
+				Field = Property.Path<ElasticsearchProject>(p=>p.Name),
+				Value = "value"
+			} && new PrefixQuery()
+			{
+				Field = "prefix_field", 
+				Value = "prefi", 
+				Rewrite = RewriteMultiTerm.ConstantScoreBoolean
+			};
+
+			var request = new SearchRequest
+			{
+				From = 0,
+				Size = 20,
+				Query = query
+				
+			};
+			var response = this._client.Search<ElasticsearchProject>(request);
+			this._status = response.ConnectionStatus;
+		}
+
+		[Test]
+		public void Url()
+		{
+			this._status.RequestUrl.Should().EndWith("/nest_test_data/_search");
+			this._status.RequestMethod.Should().Be("POST");
+		}
+	
+	}
+}