fix #2398 add script source

src/main/java/org/codelibs/fess/es/client/FessEsClient.java

@@ -349,7 +349,9 @@ public class FessEsClient implements Client {
     }
 
     public boolean reindex(final String fromIndex, final String toIndex, final boolean waitForCompletion) {
-        final String source = "{\"source\":{\"index\":\"" + fromIndex + "\"},\"dest\":{\"index\":\"" + toIndex + "\"}}";
+        final String source =
+                "{\"source\":{\"index\":\"" + fromIndex + "\"},\"dest\":{\"index\":\"" + toIndex + "\"}," + "\"script\":{\"source\":\""
+                        + ComponentUtil.getLanguageHelper().getReindexScriptSource() + "\"}}";
         try (CurlResponse response =
                 ComponentUtil.getCurlHelper().post("/_reindex").param("wait_for_completion", Boolean.toString(waitForCompletion))
                         .body(source).execute()) {

src/main/java/org/codelibs/fess/helper/LanguageHelper.java

@@ -15,7 +15,9 @@
  */
 package org.codelibs.fess.helper;
 
+import java.util.Arrays;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import javax.annotation.PostConstruct;
 
@@ -137,4 +139,16 @@ public class LanguageHelper {
         return new Script(buf.toString());
     }
 
+    public String getReindexScriptSource() {
+        final FessConfig fessConfig = ComponentUtil.getFessConfig();
+        String langField = fessConfig.getIndexFieldLang();
+        String code =
+                Arrays.stream(langFields).map(s -> "ctx._source['" + s + "_'+ctx._source." + langField + "]=ctx._source." + s)
+                        .collect(Collectors.joining(";"));
+        if (logger.isDebugEnabled()) {
+            logger.debug("reindex script: {}", code);
+        }
+        return "if(ctx._source." + langField + "!=null){" + code + "}";
+    }
+
 }