--- a/src/java.base/windows/classes/sun/util/locale/provider/HostLocaleProviderAdapterImpl.java	Wed Mar 13 12:02:04 2019 +0000
+++ b/src/java.base/windows/classes/sun/util/locale/provider/HostLocaleProviderAdapterImpl.java	Wed Mar 13 13:05:37 2019 +0900
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -510,8 +510,15 @@
             public String getDisplayCountry(String countryCode, Locale locale) {
                 // Retrieves the display country name by calling
                 // GetLocaleInfoEx(LOCALE_SLOCALIZEDCOUNTRYNAME).
-                return getDisplayString(locale.toLanguageTag(),
-                            DN_LOCALE_REGION, nativeDisplayLanguage+"-"+countryCode);
+                String str = getDisplayString(locale.toLanguageTag(),
+                                 DN_LOCALE_REGION,
+                                 nativeDisplayLanguage+"-"+countryCode);
+                // Hack: Windows 10 returns translated "Unknown Region (XX)"
+                // for localized XX region name. Take that as not known.
+                if (str != null && str.endsWith("("+countryCode+")")) {
+                    return null;
+                }
+                return str;
             }
 
             @Override

--- a/src/java.base/windows/native/libjava/HostLocaleProviderAdapter_md.c	Wed Mar 13 12:02:04 2019 +0000
+++ b/src/java.base/windows/native/libjava/HostLocaleProviderAdapter_md.c	Wed Mar 13 13:05:37 2019 +0900
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -168,11 +168,6 @@
     }
 };
 
-
-// Localized region name for unknown regions (Windows 10)
-#define UNKNOWN_REGION  L"Unknown Region ("
-#define UNKNOWN_REGION_SIZE wcslen(UNKNOWN_REGION)
-
 /*
  * Class:     sun_util_locale_provider_HostLocaleProviderAdapterImpl
  * Method:    initialize
@@ -755,15 +750,10 @@
     (*env)->ReleaseStringChars(env, jStr, pjChar);
 
     if (got) {
-        // Hack: Windows 10 returns "Unknown Region (XX)" for localized XX region name.
-        // Take that as not known.
-        if (type != sun_util_locale_provider_HostLocaleProviderAdapterImpl_DN_LOCALE_REGION ||
-            wcsncmp(UNKNOWN_REGION, buf, UNKNOWN_REGION_SIZE) != 0) {
-            return (*env)->NewString(env, buf, (jsize)wcslen(buf));
-        }
+        return (*env)->NewString(env, buf, (jsize)wcslen(buf));
+    } else {
+        return NULL;
     }
-
-    return NULL;
 }
 
 int getLocaleInfoWrapper(const jchar *langtag, LCTYPE type, LPWSTR data, int buflen) {

--- a/test/jdk/java/util/Locale/LocaleProviders.java	Wed Mar 13 12:02:04 2019 +0000
+++ b/test/jdk/java/util/Locale/LocaleProviders.java	Wed Mar 13 13:05:37 2019 +0900
@@ -72,6 +72,10 @@
                 bug8027289Test(args[1]);
                 break;
 
+            case "bug8220227Test":
+                bug8220227Test();
+                break;
+
             default:
                 throw new RuntimeException("Test method '"+methodName+"' not found.");
         }
@@ -249,4 +253,15 @@
             }
         }
     }
+
+    static void bug8220227Test() {
+        if (System.getProperty("os.name").startsWith("Windows")) {
+            Locale l = new Locale("xx","XX");
+            String country = l.getDisplayCountry();
+            if (country.endsWith("(XX)")) {
+                throw new RuntimeException(
+                        "Unexpected Region name: " + country);
+            }
+        }
+    }
 }

--- a/test/jdk/java/util/Locale/LocaleProvidersRun.java	Wed Mar 13 12:02:04 2019 +0000
+++ b/test/jdk/java/util/Locale/LocaleProvidersRun.java	Wed Mar 13 13:05:37 2019 +0900
@@ -25,7 +25,7 @@
  * @test
  * @bug 6336885 7196799 7197573 7198834 8000245 8000615 8001440 8008577
  *      8010666 8013086 8013233 8013903 8015960 8028771 8054482 8062006
- *      8150432 8215913
+ *      8150432 8215913 8220227
  * @summary tests for "java.locale.providers" system property
  * @library /test/lib
  * @build LocaleProviders
@@ -148,6 +148,12 @@
             testRun("COMPAT,HOST", "bug8027289Test", "FFE5", "", "");
             testRun("HOST", "bug8027289Test", "00A5", "", "");
         }
+
+        //testing 8220227 fix. (Windows only)
+        if (!defLang.equals("en")) {
+            testRun("HOST", "bug8220227Test", "", "", "");
+        }
+
     }
 
     private static void testRun(String prefList, String methodName,