Revert "COMPAT locale provider will be removed in a future release (#13988)"

CHANGELOG-3.0.md

@@ -17,7 +17,6 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Dependencies
 
 ### Changed
-- Changed locale provider from COMPAT to CLDR ([13988](https://github.com/opensearch-project/OpenSearch/pull/13988))
 - Migrate client transports to Apache HttpClient / Core 5.x ([#4459](https://github.com/opensearch-project/OpenSearch/pull/4459))
 - Change http code on create index API with bad input raising NotXContentException from 500 to 400 ([#4773](https://github.com/opensearch-project/OpenSearch/pull/4773))
 - Improve summary error message for invalid setting updates ([#4792](https://github.com/opensearch-project/OpenSearch/pull/4792))

buildSrc/src/main/java/org/opensearch/gradle/OpenSearchTestBasePlugin.java

@@ -110,8 +110,8 @@
                     if (BuildParams.getRuntimeJavaVersion() == JavaVersion.VERSION_1_8) {
                         test.systemProperty("java.locale.providers", "SPI,JRE");
                     } else {
-                        test.systemProperty("java.locale.providers", "SPI,CLDR");
+                        test.systemProperty("java.locale.providers", "SPI,COMPAT");
                         if (test.getJavaVersion().compareTo(JavaVersion.VERSION_17) < 0) {
                             test.jvmArgs("--illegal-access=warn");
                         }
                     }

distribution/tools/launchers/src/main/java/org/opensearch/tools/launchers/SystemJvmOptions.java

@@ -105,8 +105,13 @@ private static String javaLocaleProviders() {
            SPI setting is used to allow loading custom CalendarDataProvider
            in jdk8 it has to be loaded from jre/lib/ext,
            in jdk9+ it is already within ES project and on a classpath
+
+           Due to internationalization enhancements in JDK 9 OpenSearch need to set the provider to COMPAT otherwise time/date
+           parsing will break in an incompatible way for some date patterns and locales.
+           //TODO COMPAT will be deprecated in at some point, see please https://bugs.openjdk.java.net/browse/JDK-8232906
+          See also: documentation in <code>server/org.opensearch.common.time.IsoCalendarDataProvider</code>
          */
-        return "-Djava.locale.providers=SPI,CLDR";
+        return "-Djava.locale.providers=SPI,COMPAT";
     }
 
 }

gradle/ide.gradle

@@ -81,7 +81,7 @@ if (System.getProperty('idea.active') == 'true') {
         }
         runConfigurations {
           defaults(JUnit) {
-            vmParameters = '-ea -Djava.locale.providers=SPI,CLDR'
+            vmParameters = '-ea -Djava.locale.providers=SPI,COMPAT'
             if (BuildParams.runtimeJavaVersion > JavaVersion.VERSION_17) {
               vmParameters += ' -Djava.security.manager=allow'
             }

server/src/internalClusterTest/java/org/opensearch/search/query/SearchQueryIT.java

@@ -1914,8 +1914,14 @@ public void testRangeQueryWithTimeZone() throws Exception {
      * Test range with a custom locale, e.g. "de" in this case. Documents here mention the day of week
      * as "Mi" for "Mittwoch (Wednesday" and "Do" for "Donnerstag (Thursday)" and the month in the query
      * as "Dez" for "Dezember (December)".
+     * Note: this test currently needs the JVM arg `-Djava.locale.providers=SPI,COMPAT` to be set.
+     * When running with gradle this is done implicitly through the BuildPlugin, but when running from
+     * an IDE this might need to be set manually in the run configuration. See also CONTRIBUTING.md section
+     * on "Configuring IDEs And Running Tests".
      */
     public void testRangeQueryWithLocaleMapping() throws Exception {
+        assert ("SPI,COMPAT".equals(System.getProperty("java.locale.providers"))) : "`-Djava.locale.providers=SPI,COMPAT` needs to be set";
+
         assertAcked(
             prepareCreate("test").setMapping(
                 jsonBuilder().startObject()
@@ -1932,21 +1938,17 @@ public void testRangeQueryWithLocaleMapping() throws Exception {
 
         indexRandom(
             true,
-            client().prepareIndex("test").setId("1").setSource("date_field", "Mi., 06 Dez. 2000 02:55:00 -0800"),
-            client().prepareIndex("test").setId("2").setSource("date_field", "Do., 07 Dez. 2000 02:55:00 -0800")
+            client().prepareIndex("test").setId("1").setSource("date_field", "Mi, 06 Dez 2000 02:55:00 -0800"),
+            client().prepareIndex("test").setId("2").setSource("date_field", "Do, 07 Dez 2000 02:55:00 -0800")
         );
 
         SearchResponse searchResponse = client().prepareSearch("test")
-            .setQuery(
-                QueryBuilders.rangeQuery("date_field").gte("Di., 05 Dez. 2000 02:55:00 -0800").lte("Do., 07 Dez. 2000 00:00:00 -0800")
-            )
+            .setQuery(QueryBuilders.rangeQuery("date_field").gte("Di, 05 Dez 2000 02:55:00 -0800").lte("Do, 07 Dez 2000 00:00:00 -0800"))
             .get();
         assertHitCount(searchResponse, 1L);
 
         searchResponse = client().prepareSearch("test")
-            .setQuery(
-                QueryBuilders.rangeQuery("date_field").gte("Di., 05 Dez. 2000 02:55:00 -0800").lte("Fr., 08 Dez. 2000 00:00:00 -0800")
-            )
+            .setQuery(QueryBuilders.rangeQuery("date_field").gte("Di, 05 Dez 2000 02:55:00 -0800").lte("Fr, 08 Dez 2000 00:00:00 -0800"))
             .get();
         assertHitCount(searchResponse, 2L);
     }

server/src/test/java/org/opensearch/index/mapper/DateFieldMapperTests.java

@@ -208,7 +208,7 @@ public void testChangeLocale() throws IOException {
             fieldMapping(b -> b.field("type", "date").field("format", "E, d MMM yyyy HH:mm:ss Z").field("locale", "de"))
         );
 
-        mapper.parse(source(b -> b.field("field", "Mi., 06 Dez. 2000 02:55:00 -0800")));
+        mapper.parse(source(b -> b.field("field", "Mi, 06 Dez 2000 02:55:00 -0800")));
     }
 
     public void testNullValue() throws IOException {