--- a/src/java.base/share/classes/sun/util/locale/provider/CalendarNameProviderImpl.java	Tue May 21 15:59:46 2019 -0400
+++ b/src/java.base/share/classes/sun/util/locale/provider/CalendarNameProviderImpl.java	Tue May 21 13:40:56 2019 -0700
@@ -257,11 +257,13 @@
         return langtags;
     }
 
+    // Check if each string is unique, except null or empty strings,
+    // as these strings are used for keys in the name-to-value map.
     private boolean hasDuplicates(String[] strings) {
         int len = strings.length;
         for (int i = 0; i < len - 1; i++) {
             String a = strings[i];
-            if (a != null) {
+            if (a != null && !a.isEmpty()) {
                 for (int j = i + 1; j < len; j++) {
                     if (a.equals(strings[j]))  {
                         return true;

--- a/test/jdk/java/time/test/java/time/chrono/TestEraDisplayName.java	Tue May 21 15:59:46 2019 -0400
+++ b/test/jdk/java/time/test/java/time/chrono/TestEraDisplayName.java	Tue May 21 13:40:56 2019 -0700
@@ -28,7 +28,9 @@
 import java.time.*;
 import java.time.chrono.*;
 import java.time.format.*;
+import java.util.Arrays;
 import java.util.Locale;
+import java.util.stream.Stream;
 
 import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
@@ -39,13 +41,18 @@
  * chrono implementation.
  * Note: The exact result may depend on locale data provider's implementation.
  *
- * @bug 8171049
+ * @bug 8171049 8224105
  */
 @Test
 public class TestEraDisplayName {
     private static final Locale THAI = Locale.forLanguageTag("th-TH");
     private static final Locale EGYPT = Locale.forLanguageTag("ar-EG");
 
+    private static final LocalDate REIWA_1ST = LocalDate.of(2019, 5, 1);
+    private static final DateTimeFormatter JAPANESE_FORMATTER =
+         DateTimeFormatter.ofPattern("yyyy MM dd GGGG G GGGGG")
+            .withChronology(JapaneseChronology.INSTANCE);
+
     @DataProvider(name="eraDisplayName")
     Object[][] eraDisplayName() {
         return new Object[][] {
@@ -135,8 +142,22 @@
         };
     }
 
+    @DataProvider
+    Object[][] allLocales() {
+        return Arrays.stream(Locale.getAvailableLocales())
+            .map(Stream::of)
+            .map(Stream::toArray)
+            .toArray(Object[][]::new);
+    }
+
     @Test(dataProvider="eraDisplayName")
     public void test_eraDisplayName(Era era, TextStyle style, Locale locale, String expected) {
         assertEquals(era.getDisplayName(style, locale), expected);
     }
+
+    @Test(dataProvider="allLocales")
+    public void test_reiwaNames(Locale locale) throws DateTimeParseException {
+        DateTimeFormatter f = JAPANESE_FORMATTER.withLocale(locale);
+        assertEquals(LocalDate.parse(REIWA_1ST.format(f), f), REIWA_1ST);
+    }
 }