Stop Token Filter - enable_position_increments, closes elastic#1182.

modules/elasticsearch/src/main/java/org/elasticsearch/index/analysis/StopTokenFilterFactory.java

@@ -22,6 +22,7 @@
 import org.apache.lucene.analysis.StopAnalyzer;
 import org.apache.lucene.analysis.StopFilter;
 import org.apache.lucene.analysis.TokenStream;
+import org.apache.lucene.util.Version;
 import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.inject.assistedinject.Assisted;
 import org.elasticsearch.common.settings.Settings;
@@ -40,14 +41,19 @@ public class StopTokenFilterFactory extends AbstractTokenFilterFactory {
 
     private final boolean ignoreCase;
 
+    private final boolean enablePositionIncrements;
+
     @Inject public StopTokenFilterFactory(Index index, @IndexSettings Settings indexSettings, Environment env, @Assisted String name, @Assisted Settings settings) {
         super(index, indexSettings, name, settings);
         this.stopWords = Analysis.parseStopWords(env, settings, StopAnalyzer.ENGLISH_STOP_WORDS_SET);
         this.ignoreCase = settings.getAsBoolean("ignore_case", false);
+        this.enablePositionIncrements = settings.getAsBoolean("enable_position_increments", version.onOrAfter(Version.LUCENE_29));
     }
 
     @Override public TokenStream create(TokenStream tokenStream) {
-        return new StopFilter(version, tokenStream, stopWords, ignoreCase);
+        StopFilter filter = new StopFilter(version, tokenStream, stopWords, ignoreCase);
+        filter.setEnablePositionIncrements(enablePositionIncrements);
+        return filter;
     }
 
     public Set<?> stopWords() {
@@ -57,4 +63,8 @@ public Set<?> stopWords() {
     public boolean ignoreCase() {
         return ignoreCase;
     }
+
+    public boolean enablePositionIncrements() {
+        return this.enablePositionIncrements;
+    }
 }