Query DSL: throw an exception if array passed to `term` query.

Closes #11246
Closes #11384

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

@@ -89,6 +89,8 @@ public class TermQueryParser implements QueryParser {
                     fieldName = currentFieldName;
                     value = parser.objectBytes();
                 }
+            } else if (token == XContentParser.Token.START_ARRAY) {
+                throw new QueryParsingException(parseContext, "[term] query does not support array of values");
             }
         }
 

src/test/java/org/elasticsearch/index/query/SimpleIndexQueryParserTests.java

@@ -516,6 +516,13 @@ public class SimpleIndexQueryParserTests extends ElasticsearchSingleNodeTest {
         assertThat(fieldQuery.getTerm().bytes(), equalTo(indexedValueForSearch(34l)));
     }
 
+    @Test(expected = QueryParsingException.class)
+    public void testTermQueryArrayInvalid() throws IOException {
+        IndexQueryParserService queryParser = queryParser();
+        String query = copyToStringFromClasspath("/org/elasticsearch/index/query/term-array-invalid.json");
+        unwrapTermQuery(queryParser.parse(query).query());
+    }
+
     private static TermQuery unwrapTermQuery(Query q) {
         assertThat(q, instanceOf(TermQuery.class));
         return (TermQuery) q;

src/test/java/org/elasticsearch/index/query/term-array-invalid.json

@@ -0,0 +1,5 @@
+{
+    "term": {
+        "age": [34, 35]
+    }
+}