Make strategy optional in GeoShapeQueryBuilder readFrom and writeTo

The field is optional everywhere else but in the serialization methods, which causes problems. Also expanded tests so that they can catch this type of problem.

Closes #13963

Author: javanna

core/src/main/java/org/elasticsearch/index/query/GeoShapeQueryBuilder.java

@@ -70,7 +70,7 @@ public class GeoShapeQueryBuilder extends AbstractQueryBuilder<GeoShapeQueryBuil
     // and Equals so ShapeBuilder can be used here
     private BytesReference shapeBytes;
 
-    private SpatialStrategy strategy = null;
+    private SpatialStrategy strategy;
 
     private final String indexedShapeId;
     private final String indexedShapeType;
@@ -429,7 +429,9 @@ protected GeoShapeQueryBuilder doReadFrom(StreamInput in) throws IOException {
             }
         }
         builder.relation = ShapeRelation.DISJOINT.readFrom(in);
-        builder.strategy = SpatialStrategy.RECURSIVE.readFrom(in);
+        if (in.readBoolean()) {
+            builder.strategy = SpatialStrategy.RECURSIVE.readFrom(in);
+        }
         return builder;
     }
 
@@ -447,7 +449,12 @@ protected void doWriteTo(StreamOutput out) throws IOException {
             out.writeOptionalString(indexedShapePath);
         }
         relation.writeTo(out);
-        strategy.writeTo(out);
+        if (strategy == null) {
+            out.writeBoolean(false);
+        } else {
+            out.writeBoolean(true);
+            strategy.writeTo(out);
+        }
     }
 
     @Override

core/src/test/java/org/elasticsearch/index/query/GeoShapeQueryBuilderTests.java

@@ -77,10 +77,12 @@ protected GeoShapeQueryBuilder doCreateTestQueryBuilder() {
                 builder.indexedShapePath(indexedShapePath);
             }
         }
-        SpatialStrategy strategy = randomFrom(SpatialStrategy.values());
-        builder.strategy(strategy);
-        if (strategy != SpatialStrategy.TERM) {
-            builder.relation(randomFrom(ShapeRelation.values()));
+        if (randomBoolean()) {
+            SpatialStrategy strategy = randomFrom(SpatialStrategy.values());
+            builder.strategy(strategy);
+            if (strategy != SpatialStrategy.TERM) {
+                builder.relation(randomFrom(ShapeRelation.values()));
+            }
         }
         return builder;
     }
@@ -105,9 +107,7 @@ protected GetResponse executeGet(GetRequest getRequest) {
         } catch (IOException ex) {
             throw new ElasticsearchException("boom", ex);
         }
-        GetResponse response = new GetResponse(new GetResult(indexedShapeIndex, indexedShapeType, indexedShapeId, 0, true, new BytesArray(
-                json), null));
-        return response;
+        return new GetResponse(new GetResult(indexedShapeIndex, indexedShapeType, indexedShapeId, 0, true, new BytesArray(json), null));
     }
 
     @After
@@ -149,7 +149,7 @@ public void testNoFieldName() throws Exception {
     @Test
     public void testNoShape() throws IOException {
         try {
-            GeoShapeQueryBuilder builder = new GeoShapeQueryBuilder(GEO_SHAPE_FIELD_NAME, (ShapeBuilder) null);
+            new GeoShapeQueryBuilder(GEO_SHAPE_FIELD_NAME, (ShapeBuilder) null);
             fail("exception expected");
         } catch (IllegalArgumentException e) {
             // expected
@@ -158,12 +158,12 @@ public void testNoShape() throws IOException {
 
     @Test(expected = IllegalArgumentException.class)
     public void testNoIndexedShape() throws IOException {
-        new GeoShapeQueryBuilder(GEO_SHAPE_FIELD_NAME, (String) null, "type");
+        new GeoShapeQueryBuilder(GEO_SHAPE_FIELD_NAME, null, "type");
     }
 
     @Test(expected = IllegalArgumentException.class)
     public void testNoIndexedShapeType() throws IOException {
-        new GeoShapeQueryBuilder(GEO_SHAPE_FIELD_NAME, "id", (String) null);
+        new GeoShapeQueryBuilder(GEO_SHAPE_FIELD_NAME, "id", null);
     }
 
     @Test(expected=IllegalArgumentException.class)