Handle specialized term queries in MappedFieldType.extractTerm(TermQuery) (#21889)

For some fields we have a specialized implementation of a TermQuery that is specific for the field.
When these kind of fields are used in a wildcard query or a span term query it fails with an exception because they don't recognize the specialized form.
The impacted fields are [_all] and [_type] and the impacted queries are [span_term] and [wilcard].
This change handles these forms and correctly extracts the term inside them for further use.

Fixes #21882

core/src/main/java/org/elasticsearch/index/mapper/AllFieldMapper.java

@@ -19,7 +19,6 @@
 
 package org.elasticsearch.index.mapper;
 
-import org.apache.lucene.document.Field;
 import org.apache.lucene.index.IndexOptions;
 import org.apache.lucene.index.IndexableField;
 import org.apache.lucene.index.Term;

core/src/main/java/org/elasticsearch/index/mapper/MappedFieldType.java

@@ -35,6 +35,7 @@ import org.apache.lucene.search.BoostQuery;
 import org.elasticsearch.action.fieldstats.FieldStats;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.joda.DateMathParser;
+import org.elasticsearch.common.lucene.all.AllTermQuery;
 import org.elasticsearch.common.unit.Fuzziness;
 import org.elasticsearch.index.analysis.NamedAnalyzer;
 import org.elasticsearch.index.fielddata.IndexFieldData;
@@ -463,6 +464,12 @@ public abstract class MappedFieldType extends FieldType {
         while (termQuery instanceof BoostQuery) {
             termQuery = ((BoostQuery) termQuery).getQuery();
         }
+        if (termQuery instanceof AllTermQuery) {
+            return ((AllTermQuery) termQuery).getTerm();
+        } else if (termQuery instanceof TypeFieldMapper.TypesQuery) {
+            assert ((TypeFieldMapper.TypesQuery) termQuery).getTerms().length == 1;
+            return new Term(TypeFieldMapper.NAME, ((TypeFieldMapper.TypesQuery) termQuery).getTerms()[0]);
+        }
         if (termQuery instanceof TermQuery == false) {
             throw new IllegalArgumentException("Cannot extract a term from a query of type "
                     + termQuery.getClass() + ": " + termQuery);

core/src/main/java/org/elasticsearch/index/mapper/TypeFieldMapper.java

@@ -186,6 +186,10 @@ public class TypeFieldMapper extends MetadataFieldMapper {
             this.types = types;
         }
 
+        public BytesRef[] getTerms() {
+            return types;
+        }
+
         @Override
         public Query rewrite(IndexReader reader) throws IOException {
             final int threshold = Math.min(BOOLEAN_REWRITE_TERM_COUNT_THRESHOLD, BooleanQuery.getMaxClauseCount());

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

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.index.query;
 
+import com.fasterxml.jackson.core.io.JsonStringEncoder;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.TermQuery;
@@ -26,8 +27,6 @@ import org.apache.lucene.search.spans.SpanTermQuery;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.lucene.BytesRefs;
 import org.elasticsearch.index.mapper.MappedFieldType;
-
-import com.fasterxml.jackson.core.io.JsonStringEncoder;
 import org.elasticsearch.search.internal.SearchContext;
 
 import java.io.IOException;
@@ -132,4 +131,13 @@ public class SpanTermQueryBuilderTests extends AbstractTermQueryTestCase<SpanTer
         assertEquals("[span_term] query doesn't support multiple fields, found [message1] and [message2]", e.getMessage());
     }
 
+    public void testWithMetaDataField() throws IOException {
+        QueryShardContext context = createShardContext();
+        for (String field : new String[]{"_type", "_all"}) {
+            SpanTermQueryBuilder spanTermQueryBuilder = new SpanTermQueryBuilder(field, "toto");
+            Query query = spanTermQueryBuilder.toQuery(context);
+            Query expected = new SpanTermQuery(new Term(field, "toto"));
+            assertEquals(expected, query);
+        }
+    }
 }

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

@@ -19,6 +19,7 @@
 
 package org.elasticsearch.index.query;
 
+import org.apache.lucene.index.Term;
 import org.apache.lucene.search.Query;
 import org.apache.lucene.search.WildcardQuery;
 import org.elasticsearch.common.ParsingException;
@@ -125,4 +126,14 @@ public class WildcardQueryBuilderTests extends AbstractQueryTestCase<WildcardQue
         e = expectThrows(ParsingException.class, () -> parseQuery(shortJson));
         assertEquals("[wildcard] query doesn't support multiple fields, found [user1] and [user2]", e.getMessage());
     }
+
+    public void testWithMetaDataField() throws IOException {
+        QueryShardContext context = createShardContext();
+        for (String field : new String[]{"_type", "_all"}) {
+            WildcardQueryBuilder wildcardQueryBuilder = new WildcardQueryBuilder(field, "toto");
+            Query query = wildcardQueryBuilder.toQuery(context);
+            Query expected = new WildcardQuery(new Term(field, "toto"));
+            assertEquals(expected, query);
+        }
+    }
 }