Parent/child: Check if there is a search context, otherwise throw a query parse exception.

Also added a bwc test that runs a delete by query with a has_child query and verifies that only that operation is ignored when recovering from disk during a upgrade.

Closes #8031
Closes #8177

src/main/java/org/elasticsearch/index/query/QueryParserUtils.java

@@ -33,8 +33,13 @@ public final class QueryParserUtils {
      * Ensures that the query parsing wasn't invoked via the delete by query api.
      */
     public static void ensureNotDeleteByQuery(String name, QueryParseContext parseContext) {
-        if (TransportShardDeleteByQueryAction.DELETE_BY_QUERY_API.equals(SearchContext.current().source())) {
+        SearchContext context = SearchContext.current();
-            throw new QueryParsingException(parseContext.index(), "[" + name + "] unsupported in delete_by_query api");
+        if (context == null) {
+            throw new QueryParsingException(parseContext.index(), "[" + name + "] query and filter requires a search context");
+        }
+
+        if (TransportShardDeleteByQueryAction.DELETE_BY_QUERY_API.equals(context.source())) {
+            throw new QueryParsingException(parseContext.index(), "[" + name + "] query and filter unsupported in delete_by_query api");
         }
     }
 

src/test/java/org/elasticsearch/bwcompat/ParentChildDeleteByQueryBackwardsCompatibilityTest.java

@@ -0,0 +1,114 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.bwcompat;
+
+import org.elasticsearch.Version;
+import org.elasticsearch.action.index.IndexRequestBuilder;
+import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.test.ElasticsearchBackwardsCompatIntegrationTest;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.elasticsearch.index.query.QueryBuilders.hasChildQuery;
+import static org.elasticsearch.index.query.QueryBuilders.matchAllQuery;
+import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.*;
+import static org.hamcrest.core.Is.is;
+
+/**
+ */
+public class ParentChildDeleteByQueryBackwardsCompatibilityTest extends ElasticsearchBackwardsCompatIntegrationTest {
+
+    @BeforeClass
+    public static void checkVersion() {
+        assumeTrue("parent child queries in delete by query is forbidden from 1.1.2 and up", globalCompatibilityVersion().onOrBefore(Version.V_1_1_1));
+    }
+
+    @Override
+    public void assertAllShardsOnNodes(String index, String pattern) {
+        super.assertAllShardsOnNodes(index, pattern);
+    }
+
+    @Override
+    protected Settings externalNodeSettings(int nodeOrdinal) {
+        return ImmutableSettings.builder()
+                .put(super.externalNodeSettings(nodeOrdinal))
+                .put("index.translog.disable_flush", true)
+                .build();
+    }
+
+    @Test
+    public void testHasChild() throws Exception {
+        assertAcked(prepareCreate("idx")
+                .setSettings(ImmutableSettings.builder()
+                                .put(indexSettings())
+                                .put("index.refresh_interval", "-1")
+                                .put("index.routing.allocation.exclude._name", backwardsCluster().newNodePattern())
+                )
+                .addMapping("parent")
+                .addMapping("child", "_parent", "type=parent"));
+
+        List<IndexRequestBuilder> requests = new ArrayList<>();
+        requests.add(client().prepareIndex("idx", "parent", "1").setSource("{}"));
+        requests.add(client().prepareIndex("idx", "child", "1").setParent("1").setSource("{}"));
+        indexRandom(true, requests);
+
+        SearchResponse response = client().prepareSearch("idx")
+                .setQuery(hasChildQuery("child", matchAllQuery()))
+                .get();
+        assertNoFailures(response);
+        assertHitCount(response, 1);
+
+        client().prepareDeleteByQuery("idx")
+                .setQuery(hasChildQuery("child", matchAllQuery()))
+                .get();
+        refresh();
+
+        response = client().prepareSearch("idx")
+                .setQuery(hasChildQuery("child", matchAllQuery()))
+                .get();
+        assertNoFailures(response);
+        assertHitCount(response, 0);
+
+        client().prepareIndex("idx", "type", "1").setSource("{}").get();
+        assertThat(client().prepareGet("idx", "type", "1").get().isExists(), is(true));
+
+        backwardsCluster().upgradeAllNodes();
+        backwardsCluster().allowOnAllNodes("idx");
+        ensureGreen("idx");
+
+        response = client().prepareSearch("idx")
+                .setQuery(hasChildQuery("child", matchAllQuery()))
+                .get();
+        assertNoFailures(response);
+        assertHitCount(response, 1); // The delete by query has failed on recovery so that parent doc is still there
+
+        // But the rest of the recovery did execute, we just skipped over the delete by query with the p/c query.
+        assertThat(client().prepareGet("idx", "type", "1").get().isExists(), is(true));
+        response = client().prepareSearch("idx").setTypes("type").get();
+        assertNoFailures(response);
+        assertHitCount(response, 1);
+    }
+
+}