Android Patch: Fix BCP 47 locale extension in ULocale for first usage

Upstream ticket: http://bugs.icu-project.org/trac/ticket/13776

- For the first usage of locale extension, there is interdependency between ULocale and KeyTypeData.
  The example call stack would be:
  ULocale.forLocale -> KeyTypeData.toLegacyKey -> KeyTypeData.<clinit>
  -> ULocale.getDefault -> ULocale.forLocale -> KeyTypeData.toLegacyKey.

- Break the inter-dependency by not using ULocale.getDefault for fallback
  icu4c/source/data/misc/keyTypeData.txt indicates "no fallback" in the resource bundle.
  ==========================
  keyTypeData:table(nofallback)

  ICUResourceBundle#instantiateBundle doesn't seem to use the value of
  ULocale.getDefault foe loading the resource if the resource bundle has no fallback.
  ======= ICUResourceBundle#instantiateBundle =======
  if (openType == OpenType.DIRECT || (b != null && b.getNoFallback())) {
      return b;
  }
  ----
  <use default locale>
  ----
  ==================================================

  Before going into instantiateBundle(), if the caller didn't request
  disableFallback or OpenType.DIRECT, the code calls ULocale.getDefault().
  If the caller did, then a null String is used for the defaultID.
  =================================================
  public static ICUResourceBundle getBundleInstance(String baseName, String localeID,
          ClassLoader root, OpenType openType) {
      if (baseName == null) {
          baseName = ICUData.ICU_BASE_NAME;
      }
      localeID = ULocale.getBaseName(localeID);
      ICUResourceBundle b;
      if (openType == OpenType.LOCALE_DEFAULT_ROOT) {
          b = instantiateBundle(baseName, localeID, ULocale.getDefault().getBaseName(),
                  root, openType);
      } else {
          b = instantiateBundle(baseName, localeID, null, root, openType);
      }
      if(b==null){
          throw new MissingResourceException(
                  "Could not find the bundle "+ baseName+"/"+ localeID+".res","","");
      }
      return b;
  }
  ================================================
  I verified that the bundle object's noFallback field is true for this data file.
- Add a test that will fail individually when the bug occurs.
  I don't know how to de-initalize class KeyTypeData during the test,
  but we could potentially put the test into a separate test suite.
  Other codes in many places, e.g. JUnit, Zygote, framework,
  could still hide the bug by initializing KeyTypeMap and being the first victim of the bug.

Bug: 70943715
Test: cts-tradefed run cts-dev -m CtsIcuTestCases -t android.icu.dev.test.util.ULocaleTest#TestForLanguageTagBug13776
      pass after the CL. previously, it will fail if running individually.
Test: cts-tradefed run cts-dev -m CtsIcuTestCases
Test: cts-tradefed run cts-dev -m CtsLibcoreTestCases
Test: ant check
Change-Id: I50654a262777426c984023354797c91efaef9baf

1 files changed, 8 insertions, 0 deletions

diff --git a/icu4j/main/classes/core/src/com/ibm/icu/impl/locale/KeyTypeData.java b/icu4j/main/classes/core/src/com/ibm/icu/impl/locale/KeyTypeData.java
index a8dda07af..776d0f0c0 100644
--- a/icu4j/main/classes/core/src/com/ibm/icu/impl/locale/KeyTypeData.java
+++ b/icu4j/main/classes/core/src/com/ibm/icu/impl/locale/KeyTypeData.java
@@ -210,10 +210,18 @@ public class KeyTypeData {
     }
 
     private static void initFromResourceBundle() {
+        // Android patch: Avoid inter-dependency issue on ULocale.getDefault(). Ticket#13776
+        /*
         UResourceBundle keyTypeDataRes = UResourceBundle.getBundleInstance(
                 ICUData.ICU_BASE_NAME,
                 "keyTypeData",
                 ICUResourceBundle.ICU_DATA_CLASS_LOADER);
+         */
+        UResourceBundle keyTypeDataRes = ICUResourceBundle.getBundleInstance(
+                ICUData.ICU_BASE_NAME,
+                "keyTypeData",
+                ICUResourceBundle.ICU_DATA_CLASS_LOADER,
+                ICUResourceBundle.OpenType.DIRECT);
 
         getKeyInfo(keyTypeDataRes.get("keyInfo"));
         getTypeInfo(keyTypeDataRes.get("typeInfo"));