Don't reset TokenStreams twice when highlighting.

When using PlainHighlighter, TokenStreams are resetted both before highlighting
and at the beginning of highlighting, causing issues with analyzers that read
in reset() such as PatternAnalyzer. This commit removes the call to reset which
was performed before passing the TokenStream to the highlighter.

Close #3200

src/main/java/org/elasticsearch/search/highlight/PlainHighlighter.java

@@ -127,7 +127,6 @@ public class PlainHighlighter implements Highlighter {
                 String text = textToHighlight.toString();
                 Analyzer analyzer = context.mapperService().documentMapper(hitContext.hit().type()).mappers().indexAnalyzer();
                 TokenStream tokenStream = analyzer.tokenStream(mapper.names().indexName(), new FastStringReader(text));
-                tokenStream.reset();
                 if (!tokenStream.hasAttribute(CharTermAttribute.class) || !tokenStream.hasAttribute(OffsetAttribute.class)) {
                     // can't perform highlighting if the stream has no terms (binary token stream) or no offsets
                     continue;

src/test/java/org/elasticsearch/test/integration/search/highlight/HighlighterSearchTests.java

@@ -1469,7 +1469,7 @@ public class HighlighterSearchTests extends AbstractSharedClusterTest {
 
         ensureGreen();
 
-        client().prepareIndex("test", "type1", "1")
+        client().prepareIndex("test", "test", "1")
         .setSource(jsonBuilder().startObject()
             .field("text", "elasticsearch test")
             .field("byte", 25)
@@ -1497,4 +1497,41 @@ public class HighlighterSearchTests extends AbstractSharedClusterTest {
         assertThat(response.getFailedShards(), equalTo(0));
     }
 
+    @Test
+    // https://github.com/elasticsearch/elasticsearch/issues/3200
+    public void testResetTwice() throws Exception {
+        prepareCreate("test")
+            .setSettings(ImmutableSettings.builder()
+                .put("analysis.analyzer.my_analyzer.type", "pattern")
+                .put("analysis.analyzer.my_analyzer.pattern", "\\s+")
+            .build())
+            .addMapping("type", jsonBuilder()
+                .startObject()
+                    .startObject("type")
+                        .startObject("properties")
+                            .startObject("text")
+                                .field("type", "string")
+                                .field("analyzer", "my_analyzer")
+                            .endObject()
+                        .endObject()
+                    .endObject()
+                .endObject())
+            .execute().actionGet();
+
+        ensureGreen();
+        client().prepareIndex("test", "type", "1")
+            .setSource(jsonBuilder().startObject()
+                    .field("text", "elasticsearch test")
+                .endObject())
+            .setRefresh(true)
+            .execute().actionGet();
+
+        SearchResponse response = client().prepareSearch("test")
+                .setQuery(QueryBuilders.matchQuery("text", "test").type(MatchQueryBuilder.Type.BOOLEAN))
+                .addHighlightedField("text").execute().actionGet();
+        assertThat(response.getHits().totalHits(), equalTo(1L));
+        // PatternAnalyzer will throw an exception if it is resetted twice
+        assertThat(response.getFailedShards(), equalTo(0));
+    }
+
 }