Fixed - STOPWORDS 0 can't be defined during RSearch index creation.

redisson/src/main/java/org/redisson/RedissonSearch.java

@@ -123,10 +123,14 @@ public class RedissonSearch implements RSearch {
         if (options.isNoFreqs()) {
             args.add("NOFREQS");
         }
-        if (!options.getStopwords().isEmpty()) {
+        if (options.getStopwords() != null) {
             args.add("STOPWORDS");
-            args.add(options.getStopwords().size());
-            args.addAll(options.getStopwords());
+            if (options.getStopwords().isEmpty()) {
+                args.add(0);
+            } else {
+                args.add(options.getStopwords().size());
+                args.addAll(options.getStopwords());
+            }
         }
         if (options.isSkipInitialScan()) {
             args.add("SKIPINITIALSCAN");

redisson/src/main/java/org/redisson/api/search/index/IndexOptions.java

@@ -39,7 +39,7 @@ public final class IndexOptions {
     private String scoreField;
     private boolean noHL;
     private boolean noFreqs;
-    private List<String> stopwords = Collections.emptyList();
+    private List<String> stopwords;
     private boolean skipInitialScan;
     private IndexType on;
     private byte[] payloadField;

redisson/src/test/java/org/redisson/RedissonSearchTest.java

@@ -61,6 +61,7 @@ public class RedissonSearchTest extends DockerRedisStackTest {
         RSearch s = redisson.getSearch();
         s.createIndex("idx", IndexOptions.defaults()
                                     .on(IndexType.HASH)
+                                    .stopwords(Collections.emptyList())
                                     .prefix(Arrays.asList("doc:")),
                                     FieldIndex.text("t1"),
                                     FieldIndex.text("t2"));