Fixes class cast exception when`top_children`, `has_child` and `has_parent` queries are cached via `fquery` filter.

The error only occurs for `has_child` and `has_parent` if `score_mode` is used.
Closes #3290

src/main/java/org/elasticsearch/index/search/child/ChildrenQuery.java

@@ -93,23 +93,19 @@ public class ChildrenQuery extends Query implements SearchContext.Rewrite {
             return false;
         }
 
-        HasChildFilter that = (HasChildFilter) obj;
+        ChildrenQuery that = (ChildrenQuery) obj;
-        if (!originalChildQuery.equals(that.childQuery)) {
+        if (!originalChildQuery.equals(that.originalChildQuery)) {
             return false;
         }
         if (!childType.equals(that.childType)) {
             return false;
         }
-        if (!parentType.equals(that.parentType)) {
-            return false;
-        }
         return true;
     }
 
     @Override
     public int hashCode() {
         int result = originalChildQuery.hashCode();
-        result = 31 * result + parentType.hashCode();
         result = 31 * result + childType.hashCode();
         return result;
     }

src/main/java/org/elasticsearch/index/search/child/HasChildFilter.java

@@ -73,16 +73,12 @@ public class HasChildFilter extends Filter implements SearchContext.Rewrite {
         if (!childType.equals(that.childType)) {
             return false;
         }
-        if (!parentType.equals(that.parentType)) {
-            return false;
-        }
         return true;
     }
 
     @Override
     public int hashCode() {
         int result = childQuery.hashCode();
-        result = 31 * result + parentType.hashCode();
         result = 31 * result + childType.hashCode();
         return result;
     }

src/main/java/org/elasticsearch/index/search/child/ParentQuery.java

@@ -102,8 +102,8 @@ public class ParentQuery extends Query implements SearchContext.Rewrite {
             return false;
         }
 
-        HasParentFilter that = (HasParentFilter) obj;
+        ParentQuery that = (ParentQuery) obj;
-        if (!originalParentQuery.equals(that.parentQuery)) {
+        if (!originalParentQuery.equals(that.originalParentQuery)) {
             return false;
         }
         if (!parentType.equals(that.parentType)) {

src/main/java/org/elasticsearch/index/search/child/TopChildrenQuery.java

@@ -261,14 +261,14 @@ public class TopChildrenQuery extends Query implements SearchContext.Rewrite {
             return false;
         }
 
-        HasChildFilter that = (HasChildFilter) obj;
+        TopChildrenQuery that = (TopChildrenQuery) obj;
-        if (!originalChildQuery.equals(that.childQuery)) {
+        if (!originalChildQuery.equals(that.originalChildQuery)) {
             return false;
         }
         if (!childType.equals(that.childType)) {
             return false;
         }
-        if (!parentType.equals(that.parentType)) {
+        if (incrementalFactor != that.incrementalFactor) {
             return false;
         }
         return true;
@@ -278,7 +278,7 @@ public class TopChildrenQuery extends Query implements SearchContext.Rewrite {
     public int hashCode() {
         int result = originalChildQuery.hashCode();
         result = 31 * result + parentType.hashCode();
-        result = 31 * result + childType.hashCode();
+        result = 31 * result + incrementalFactor;
         return result;
     }
 

src/test/java/org/elasticsearch/test/integration/search/child/SimpleChildQuerySearchTests.java

@@ -169,8 +169,6 @@ public class SimpleChildQuerySearchTests extends AbstractSharedClusterTest {
 
     @Test
     public void simpleChildQuery() throws Exception {
-        client().admin().indices().prepareDelete().execute().actionGet();
-
         client().admin().indices().prepareCreate("test")
                 .setSettings(
                         ImmutableSettings.settingsBuilder()
@@ -350,6 +348,48 @@ public class SimpleChildQuerySearchTests extends AbstractSharedClusterTest {
         assertThat(searchResponse.getHits().totalHits(), equalTo(2l));
         assertThat(searchResponse.getHits().getAt(0).id(), equalTo("c1"));
         assertThat(searchResponse.getHits().getAt(1).id(), equalTo("c2"));
+
+
+    }
+
+    @Test
+    // See: https://github.com/elasticsearch/elasticsearch/issues/3290
+    public void testCachingBug_withFqueryFilter() throws Exception {
+        client().admin().indices().prepareCreate("test")
+                .setSettings(
+                        ImmutableSettings.settingsBuilder()
+                                .put("index.number_of_shards", 1)
+                                .put("index.number_of_replicas", 0)
+                ).execute().actionGet();
+        client().admin().cluster().prepareHealth().setWaitForEvents(Priority.LANGUID).setWaitForGreenStatus().execute().actionGet();
+        client().admin().indices().preparePutMapping("test").setType("child").setSource(jsonBuilder().startObject().startObject("type")
+                .startObject("_parent").field("type", "parent").endObject()
+                .endObject().endObject()).execute().actionGet();
+
+        // index simple data
+        for (int i = 0; i < 10; i++) {
+            client().prepareIndex("test", "parent", Integer.toString(i)).setSource("p_field", i).execute().actionGet();
+        }
+        for (int i = 0; i < 10; i++) {
+            client().prepareIndex("test", "child", Integer.toString(i)).setSource("c_field", i).setParent("" + 0).execute().actionGet();
+        }
+        for (int i = 0; i < 10; i++) {
+            client().prepareIndex("test", "child", Integer.toString(i + 10)).setSource("c_field", i + 10).setParent(Integer.toString(i)).execute().actionGet();
+        }
+        client().admin().indices().prepareFlush().execute().actionGet();
+        client().admin().indices().prepareRefresh().execute().actionGet();
+
+        for (int i = 0; i < 10; i++) {
+            SearchResponse searchResponse = client().prepareSearch("test").setQuery(constantScoreQuery(queryFilter(topChildrenQuery("child", matchAllQuery())).cache(true)))
+                    .execute().actionGet();
+            assertThat("Failures " + Arrays.toString(searchResponse.getShardFailures()), searchResponse.getShardFailures().length, equalTo(0));
+            searchResponse = client().prepareSearch("test").setQuery(constantScoreQuery(queryFilter(hasChildQuery("child", matchAllQuery()).scoreType("max")).cache(true)))
+                    .execute().actionGet();
+            assertThat("Failures " + Arrays.toString(searchResponse.getShardFailures()), searchResponse.getShardFailures().length, equalTo(0));
+            searchResponse = client().prepareSearch("test").setQuery(constantScoreQuery(queryFilter(hasParentQuery("parent", matchAllQuery()).scoreType("score")).cache(true)))
+                    .execute().actionGet();
+            assertThat("Failures " + Arrays.toString(searchResponse.getShardFailures()), searchResponse.getShardFailures().length, equalTo(0));
+        }
     }
 
     @Test