From 757de805d345cc6f86dfb9212304adca165295a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christoph=20B=C3=BCscher?= <christoph@elastic.co>
Date: Thu, 28 Jul 2016 11:57:17 +0200
Subject: [PATCH] `multi_match` query should produce MatchNoDocs query on
 unknown fieldname

Currently when the `fields` parameter used in a `multi_match` query contains a
wildcard expression that doesn't resolve to any field name in the target index,
MultiMatchQueryBuilder produces a `null` query. This change changes it to be a
MatchNoDocs query, since returning no documents for this case is already the
current behaviour. Also adding missing field names (with and without wildcards)
to the unit and integration test.
---
 .../index/query/MultiMatchQueryBuilder.java         |  7 ++++++-
 .../org/elasticsearch/index/search/MatchQuery.java  |  1 -
 .../index/query/MultiMatchQueryBuilderTests.java    | 13 ++++++++++++-
 .../search/query/MultiMatchQueryIT.java             |  6 +++++-
 4 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/org/elasticsearch/index/query/MultiMatchQueryBuilder.java b/core/src/main/java/org/elasticsearch/index/query/MultiMatchQueryBuilder.java
index e2d34db0b4a..41b6829994e 100644
--- a/core/src/main/java/org/elasticsearch/index/query/MultiMatchQueryBuilder.java
+++ b/core/src/main/java/org/elasticsearch/index/query/MultiMatchQueryBuilder.java
@@ -29,6 +29,7 @@ import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.lucene.search.MatchNoDocsQuery;
 import org.elasticsearch.common.regex.Regex;
 import org.elasticsearch.common.unit.Fuzziness;
 import org.elasticsearch.common.xcontent.XContentBuilder;
@@ -747,7 +748,11 @@ public class MultiMatchQueryBuilder extends AbstractQueryBuilder<MultiMatchQuery
 
         Query query = multiMatchQuery.parse(type, newFieldsBoosts, value, minimumShouldMatch);
         if (query == null) {
-            return null;
+            if (newFieldsBoosts.isEmpty()) {
+                return new MatchNoDocsQuery("[" + NAME + "] could not resolve any field names");
+            } else {
+                return new MatchNoDocsQuery("[" + NAME + "] parsing resolved to null query");
+            }
         }
         return query;
     }
diff --git a/core/src/main/java/org/elasticsearch/index/search/MatchQuery.java b/core/src/main/java/org/elasticsearch/index/search/MatchQuery.java
index 47585c2210d..835ec8e143f 100644
--- a/core/src/main/java/org/elasticsearch/index/search/MatchQuery.java
+++ b/core/src/main/java/org/elasticsearch/index/search/MatchQuery.java
@@ -280,7 +280,6 @@ public class MatchQuery {
         if (zeroTermsQuery == DEFAULT_ZERO_TERMS_QUERY) {
             return Queries.newMatchNoDocsQuery("Matching no documents because no terms present.");
         }
-
         return Queries.newMatchAllQuery();
     }
 
diff --git a/core/src/test/java/org/elasticsearch/index/query/MultiMatchQueryBuilderTests.java b/core/src/test/java/org/elasticsearch/index/query/MultiMatchQueryBuilderTests.java
index e2222002ce0..193d82b4c8e 100644
--- a/core/src/test/java/org/elasticsearch/index/query/MultiMatchQueryBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/index/query/MultiMatchQueryBuilderTests.java
@@ -53,12 +53,17 @@ import static org.hamcrest.CoreMatchers.instanceOf;
 
 public class MultiMatchQueryBuilderTests extends AbstractQueryTestCase<MultiMatchQueryBuilder> {
 
+    private static final String MISSING_WILDCARD_FIELD_NAME = "missing_*";
+    private static final String MISSING_FIELD_NAME = "missing";
+
     @Override
     protected MultiMatchQueryBuilder doCreateTestQueryBuilder() {
-        String fieldName = randomFrom(STRING_FIELD_NAME, INT_FIELD_NAME, DOUBLE_FIELD_NAME, BOOLEAN_FIELD_NAME, DATE_FIELD_NAME);
+        String fieldName = randomFrom(STRING_FIELD_NAME, INT_FIELD_NAME, DOUBLE_FIELD_NAME, BOOLEAN_FIELD_NAME, DATE_FIELD_NAME,
+                MISSING_FIELD_NAME, MISSING_WILDCARD_FIELD_NAME);
         if (fieldName.equals(DATE_FIELD_NAME)) {
             assumeTrue("test with date fields runs only when at least a type is registered", getCurrentTypes().length > 0);
         }
+
         // creates the query with random value and field name
         Object value;
         if (fieldName.equals(STRING_FIELD_NAME)) {
@@ -238,6 +243,12 @@ public class MultiMatchQueryBuilderTests extends AbstractQueryTestCase<MultiMatc
         assertThat(assertBooleanSubQuery(query, TermQuery.class, 1).getTerm(), equalTo(new Term(STRING_FIELD_NAME_2, "test")));
     }
 
+    public void testToQueryFieldMissing() throws Exception {
+        assumeTrue("test runs only when at least a type is registered", getCurrentTypes().length > 0);
+        assertThat(multiMatchQuery("test").field(MISSING_WILDCARD_FIELD_NAME).toQuery(createShardContext()), instanceOf(MatchNoDocsQuery.class));
+        assertThat(multiMatchQuery("test").field(MISSING_FIELD_NAME).toQuery(createShardContext()), instanceOf(TermQuery.class));
+    }
+
     public void testFromJson() throws IOException {
         String json =
                 "{\n" +
diff --git a/core/src/test/java/org/elasticsearch/search/query/MultiMatchQueryIT.java b/core/src/test/java/org/elasticsearch/search/query/MultiMatchQueryIT.java
index 766aff8d274..cb55f88ff80 100644
--- a/core/src/test/java/org/elasticsearch/search/query/MultiMatchQueryIT.java
+++ b/core/src/test/java/org/elasticsearch/search/query/MultiMatchQueryIT.java
@@ -237,7 +237,8 @@ public class MultiMatchQueryIT extends ESIntegTestCase {
         assertNoFailures(searchResponse);
         assertFirstHit(searchResponse, hasId("theone"));
 
-        String[] fields = {"full_name", "first_name", "last_name", "last_name_phrase", "first_name_phrase", "category_phrase", "category"};
+        String[] fields = { "full_name", "first_name", "last_name", "last_name_phrase", "first_name_phrase", "category_phrase", "category",
+                "missing_field", "missing_fields*" };
 
         String[] query = {"marvel","hero", "captain",  "america", "15", "17", "1", "5", "ultimate", "Man",
                 "marvel", "wolferine", "ninja"};
@@ -269,6 +270,9 @@ public class MultiMatchQueryIT extends ESIntegTestCase {
                     .setQuery(matchQueryBuilder).get();
             assertThat("field: " + field + " query: " + builder.toString(), multiMatchResp.getHits().getTotalHits(), equalTo(matchResp.getHits().getTotalHits()));
             SearchHits hits = multiMatchResp.getHits();
+            if (field.startsWith("missing")) {
+                assertEquals(0, hits.hits().length);
+            }
             for (int j = 0; j < hits.hits().length; j++) {
                 assertThat(hits.getHits()[j].score(), equalTo(matchResp.getHits().getHits()[j].score()));
                 assertThat(hits.getHits()[j].getId(), equalTo(matchResp.getHits().getHits()[j].getId()));