More Like This Query: replaced 'exclude' with 'include' to avoid double negation when set.

Closes #6248

docs/reference/query-dsl/queries/mlt-query.asciidoc

@@ -82,8 +82,8 @@ not specified.
 `like_text` is not specified. The texts are fetched from `fields` unless
 specified in each `doc`, and cannot be set to `_all`.
 
-|`exclude` |When using `ids`, specifies whether the documents should be
-excluded from the search. Defaults to `true`.
+|`include` |When using `ids` or `docs`, specifies whether the documents should be
+included from the search. Defaults to `false`.
 
 |`percent_terms_to_match` |The percentage of terms to match on (float
 value). Defaults to `0.3` (30 percent).

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

@@ -102,7 +102,7 @@ public class MoreLikeThisQueryBuilder extends BaseQueryBuilder implements Boosta
     private String likeText;
     private List<String> ids = new ArrayList<>();
     private List<Item> docs = new ArrayList<>();
-    private Boolean exclude = null;
+    private Boolean include = null;
     private float percentTermsToMatch = -1;
     private int minTermFreq = -1;
     private int maxQueryTerms = -1;
@@ -156,8 +156,8 @@ public class MoreLikeThisQueryBuilder extends BaseQueryBuilder implements Boosta
         return this;
     }
 
-    public MoreLikeThisQueryBuilder exclude(boolean exclude) {
-        this.exclude = exclude;
+    public MoreLikeThisQueryBuilder include(boolean include) {
+        this.include = include;
         return this;
     }
 
@@ -336,8 +336,8 @@ public class MoreLikeThisQueryBuilder extends BaseQueryBuilder implements Boosta
         if (!docs.isEmpty()) {
             builder.array("docs", docs.toArray());
         }
-        if (exclude != null) {
-            builder.field("exclude", exclude);
+        if (include != null) {
+            builder.field("include", include);
         }
         builder.endObject();
     }

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

@@ -65,7 +65,7 @@ public class MoreLikeThisQueryParser implements QueryParser {
         public static final ParseField STOP_WORDS = new ParseField("stop_words");
         public static final ParseField DOCUMENT_IDS = new ParseField("ids");
         public static final ParseField DOCUMENTS = new ParseField("docs");
-        public static final ParseField EXCLUDE = new ParseField("exclude");
+        public static final ParseField INCLUDE = new ParseField("include");
     }
 
     public MoreLikeThisQueryParser() {
@@ -92,7 +92,7 @@ public class MoreLikeThisQueryParser implements QueryParser {
         List<String> moreLikeFields = null;
         boolean failOnUnsupportedField = true;
         String queryName = null;
-        boolean exclude = true;
+        boolean include = false;
 
         XContentParser.Token token;
         String currentFieldName = null;
@@ -131,8 +131,8 @@ public class MoreLikeThisQueryParser implements QueryParser {
                     failOnUnsupportedField = parser.booleanValue();
                 } else if ("_name".equals(currentFieldName)) {
                     queryName = parser.text();
-                } else if (Fields.EXCLUDE.match(currentFieldName, parseContext.parseFlags())) {
-                    exclude = parser.booleanValue();
+                } else if (Fields.INCLUDE.match(currentFieldName, parseContext.parseFlags())) {
+                    include = parser.booleanValue();
                 } else {
                     throw new QueryParsingException(parseContext.index(), "[mlt] query does not support [" + currentFieldName + "]");
                 }
@@ -212,7 +212,7 @@ public class MoreLikeThisQueryParser implements QueryParser {
                 addMoreLikeThis(boolQuery, mltQuery, likeText.field, likeText.text);
             }
             // exclude the items from the search
-            if (exclude) {
+            if (!include) {
                 TermsFilter filter = new TermsFilter(UidFieldMapper.NAME, Uid.createUids(items));
                 ConstantScoreQuery query = new ConstantScoreQuery(filter);
                 boolQuery.add(query, BooleanClause.Occur.MUST_NOT);

src/test/java/org/elasticsearch/index/query/mlt-ids.json

@@ -14,7 +14,7 @@
         }
         ],
         "ids" : ["3", "4"],
-        "exclude" : false,
+        "include" : true,
         "min_term_freq" : 1,
         "max_query_terms" : 12
     }

src/test/java/org/elasticsearch/mlt/MoreLikeThisActionTests.java

@@ -367,7 +367,7 @@ public class MoreLikeThisActionTests extends ElasticsearchIntegrationTest {
         indexRandom(true, builders);
 
         logger.info("Running MoreLikeThis");
-        MoreLikeThisQueryBuilder queryBuilder = QueryBuilders.moreLikeThisQuery("text").ids("1").exclude(false).minTermFreq(1).minDocFreq(1);
+        MoreLikeThisQueryBuilder queryBuilder = QueryBuilders.moreLikeThisQuery("text").ids("1").include(true).minTermFreq(1).minDocFreq(1);
         SearchResponse mltResponse = client().prepareSearch().setTypes("type1").setQuery(queryBuilder).execute().actionGet();
         assertHitCount(mltResponse, 3l);
     }
@@ -472,7 +472,7 @@ public class MoreLikeThisActionTests extends ElasticsearchIntegrationTest {
         indexRandom(true, builders);
 
         logger.info("Running MoreLikeThis");
-        MoreLikeThisQueryBuilder queryBuilder = QueryBuilders.moreLikeThisQuery("text").exclude(false).minTermFreq(1).minDocFreq(1)
+        MoreLikeThisQueryBuilder queryBuilder = QueryBuilders.moreLikeThisQuery("text").include(true).minTermFreq(1).minDocFreq(1)
                 .addItem(new MoreLikeThisQueryBuilder.Item("test", "type0", "0"));
 
         String[] types = new String[numOfTypes];