Add ignore_unmapped to inner_hits (#3135)

Closes #3132

Author: russcam

src/Nest/Search/Search/InnerHits/InnerHits.cs

@@ -38,6 +38,9 @@ public interface IInnerHits
 
 		[JsonProperty("docvalue_fields")]
 		Fields DocValueFields { get; set; }
+
+		[JsonProperty("ignore_unmapped")]
+		bool? IgnoreUnmapped { get; set; }
 	}
 
 	public class InnerHits : IInnerHits
@@ -61,6 +64,8 @@ public class InnerHits : IInnerHits
 		public IScriptFields ScriptFields { get; set; }
 
 		public Fields DocValueFields { get; set; }
+
+		public bool? IgnoreUnmapped { get; set; }
 	}
 
 	[JsonObject(MemberSerialization = MemberSerialization.OptIn)]
@@ -76,6 +81,7 @@ public class InnerHitsDescriptor<T> : DescriptorBase<InnerHitsDescriptor<T>, IIn
 		bool? IInnerHits.Version { get; set; }
 		IScriptFields IInnerHits.ScriptFields { get; set; }
 		Fields IInnerHits.DocValueFields { get; set; }
+		bool? IInnerHits.IgnoreUnmapped { get; set; }
 
 		public InnerHitsDescriptor<T> From(int? from) => Assign(a => a.From = from);
 
@@ -107,5 +113,7 @@ public InnerHitsDescriptor<T> DocValueFields(Func<FieldsDescriptor<T>, IPromise<
 			Assign(a => a.DocValueFields = fields?.Invoke(new FieldsDescriptor<T>())?.Value);
 
 		public InnerHitsDescriptor<T> DocValueFields(Fields fields) => Assign(a => a.DocValueFields = fields);
+
+		public InnerHitsDescriptor<T> IgnoreUnmapped(bool? ignoreUnmapped = true) => Assign(a => a.IgnoreUnmapped = ignoreUnmapped);
 	}
 }

src/Tests/Search/Request/InnerHitsUsageTests.cs

@@ -88,7 +88,6 @@ public void Seed()
 				)
 				.Mappings(map => map
 					.Map<King>(RoyalType, m => m
-
 						.AutoMap()
 						.Properties(props =>
 							RoyalProps(props)
@@ -162,7 +161,7 @@ private void IndexAll<TRoyal, TParent>(BulkDescriptor bulk, Func<IEnumerable<TRo
 	}
 
 	/**
-	 * [[inner-hits-usage]]
+	* [[inner-hits-usage]]
 	*== Inner Hits Usage
 	*
 	* The {ref_current}/mapping-parent-field.html[parent/child] and {ref_current}/nested.html[nested] features allow the
@@ -244,7 +243,8 @@ public QueryInnerHitsApiTests(IntrusiveOperationCluster cluster, EndpointUsage u
 									highlight = new
 									{
 										fields = new { fullTextField = new { } }
-									}
+									},
+									ignore_unmapped = false
 								}
 							}
 						},
@@ -272,6 +272,7 @@ public QueryInnerHitsApiTests(IntrusiveOperationCluster cluster, EndpointUsage u
 						.DocValueFields(f=>f.Field(p=>p.Name))
 						.Name("princes")
 						.Highlight(h=>h.Fields(f=>f.Field(p=>p.FullTextField)))
+						.IgnoreUnmapped(false)
 					)
 
 				) || q.Nested(n => n
@@ -291,7 +292,8 @@ public QueryInnerHitsApiTests(IntrusiveOperationCluster cluster, EndpointUsage u
 				{
 					Name = "princes",
 					DocValueFields = Field<Prince>(p=>p.Name),
-					Highlight = Highlight.Field(Field<Prince>(p=>p.FullTextField))
+					Highlight = Highlight.Field(Field<Prince>(p=>p.FullTextField)),
+					IgnoreUnmapped = false
 				}
 			} || new NestedQuery
 			{