Aggregations: Do not take deleted documents into account in aggregations filters.

Since aggregators are only called on documents that match the query, it never
gets called on deleted documents, so by specifying `null` as live docs, we very
likely remove a BitsFilteredDocIdSet layer.

Close #8540

src/main/java/org/elasticsearch/search/aggregations/bucket/filter/FilterAggregator.java

@@ -51,7 +51,7 @@ public class FilterAggregator extends SingleBucketAggregator {
     @Override
     public void setNextReader(LeafReaderContext reader) {
         try {
-            bits = DocIdSets.toSafeBits(reader.reader(), filter.getDocIdSet(reader, reader.reader().getLiveDocs()));
+            bits = DocIdSets.toSafeBits(reader.reader(), filter.getDocIdSet(reader, null));
         } catch (IOException ioe) {
             throw new AggregationExecutionException("Failed to aggregate filter aggregator [" + name + "]", ioe);
         }

src/main/java/org/elasticsearch/search/aggregations/bucket/filters/FiltersAggregator.java

@@ -70,7 +70,7 @@ public class FiltersAggregator extends BucketsAggregator {
     public void setNextReader(LeafReaderContext reader) {
         try {
             for (int i = 0; i < filters.length; i++) {
-                bits[i] = DocIdSets.toSafeBits(reader.reader(), filters[i].filter.getDocIdSet(reader, reader.reader().getLiveDocs()));
+                bits[i] = DocIdSets.toSafeBits(reader.reader(), filters[i].filter.getDocIdSet(reader, null));
             }
         } catch (IOException ioe) {
             throw new AggregationExecutionException("Failed to aggregate filter aggregator [" + name + "]", ioe);

src/test/java/org/elasticsearch/search/aggregations/bucket/FilterTests.java

@@ -64,12 +64,17 @@ public class FilterTests extends ElasticsearchIntegrationTest {
                     .endObject()));
         }
         for (int i = numTag1Docs; i < numDocs; i++) {
-            builders.add(client().prepareIndex("idx", "type", ""+i).setSource(jsonBuilder()
+            IndexRequestBuilder req = client().prepareIndex("idx", "type", ""+i).setSource(jsonBuilder()
                     .startObject()
                     .field("value", i)
                     .field("tag", "tag2")
                     .field("name", "name" + i)
-                    .endObject()));
+                    .endObject());
+            builders.add(req);
+            if (randomBoolean()) {
+                // randomly index the document twice so that we have deleted docs that match the filter
+                builders.add(req);
+            }
         }
         prepareCreate("empty_bucket_idx").addMapping("type", "value", "type=integer").execute().actionGet();
         for (int i = 0; i < 2; i++) {

src/test/java/org/elasticsearch/search/aggregations/bucket/FiltersTests.java

@@ -60,20 +60,29 @@ public class FiltersTests extends ElasticsearchIntegrationTest {
         numTag1Docs = randomIntBetween(1, numDocs - 1);
         List<IndexRequestBuilder> builders = new ArrayList<>();
         for (int i = 0; i < numTag1Docs; i++) {
-            builders.add(client().prepareIndex("idx", "type", ""+i).setSource(jsonBuilder()
+            IndexRequestBuilder req = client().prepareIndex("idx", "type", ""+i).setSource(jsonBuilder()
                     .startObject()
                     .field("value", i + 1)
                     .field("tag", "tag1")
-                    .endObject()));
+                    .endObject());
+            builders.add(req);
+            if (randomBoolean()) {
+                // randomly index the document twice so that we have deleted docs that match the filter
+                builders.add(req);
+            }
         }
         for (int i = numTag1Docs; i < numDocs; i++) {
             numTag2Docs++;
-            builders.add(client().prepareIndex("idx", "type", ""+i).setSource(jsonBuilder()
+            IndexRequestBuilder req = client().prepareIndex("idx", "type", ""+i).setSource(jsonBuilder()
                     .startObject()
                     .field("value", i)
                     .field("tag", "tag2")
                     .field("name", "name" + i)
-                    .endObject()));
+                    .endObject());
+            builders.add(req);
+            if (randomBoolean()) {
+                builders.add(req);
+            }
         }
         prepareCreate("empty_bucket_idx").addMapping("type", "value", "type=integer").execute().actionGet();
         for (int i = 0; i < 2; i++) {