Introduce user.locale [take 2]

This reverts commit 5eba1f238e37e3fef73b492badb950225150cdcf and
adds additional code to set user.language / user.region for backwards
compatibility.

The original commit had a static initialization order bug, so this
change reorders static fields so that GRANDFATHERED_TAGS is initialized
before the default locale.

We also set user.language / user.region for backwards compatibility. The
android framework have been changed to pass in user.locale instead of
user.language / user.region but we parse that value and set
user.language / country for code that still relies on it.

bug: 17691569
Change-Id: Ie5e8ffe4bafa3977fea27289f9ffc5100288cab3

3 files changed, 133 insertions, 52 deletions

diff --git a/luni/src/main/java/java/lang/System.java b/luni/src/main/java/java/lang/System.java
index 51674e7..471b35f 100644
--- a/luni/src/main/java/java/lang/System.java
+++ b/luni/src/main/java/java/lang/System.java
@@ -50,6 +50,7 @@ import java.nio.channels.spi.SelectorProvider;
 import java.util.AbstractMap;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Set;
@@ -108,6 +109,33 @@ public final class System {
         unchangeableSystemProperties = initUnchangeableSystemProperties();
         systemProperties = createSystemProperties();
         lineSeparator = System.getProperty("line.separator");
+
+        addLegacyLocaleSystemProperties();
+    }
+
+    private static void addLegacyLocaleSystemProperties() {
+        final String locale = getProperty("user.locale", "");
+        if (!locale.isEmpty()) {
+            Locale l = Locale.forLanguageTag(locale);
+            initUnchangeableSystemProperty("user.language", l.getLanguage());
+            initUnchangeableSystemProperty("user.region", l.getCountry());
+            initUnchangeableSystemProperty("user.variant", l.getVariant());
+        } else {
+            // If "user.locale" isn't set we fall back to our old defaults of
+            // language="en" and region="US" (if unset) and don't attempt to set it.
+            // The Locale class will fall back to using user.language and
+            // user.region if unset.
+            final String language = getProperty("user.language", "");
+            final String region = getProperty("user.region", "");
+
+            if (language.isEmpty()) {
+                initUnchangeableSystemProperty("user.language", "en");
+            }
+
+            if (region.isEmpty()) {
+                initUnchangeableSystemProperty("user.region", "US");
+            }
+        }
     }
 
     /**
@@ -751,8 +779,6 @@ public final class System {
         p.put("java.vm.vendor.url", projectUrl);
 
         p.put("file.encoding", "UTF-8");
-        p.put("user.language", "en");
-        p.put("user.region", "US");
 
         try {
             StructPasswd passwd = Libcore.os.getpwuid(Libcore.os.getuid());
diff --git a/luni/src/main/java/java/util/Locale.java b/luni/src/main/java/java/util/Locale.java
index e509a6e..b1a056a 100644
--- a/luni/src/main/java/java/util/Locale.java
+++ b/luni/src/main/java/java/util/Locale.java
@@ -272,17 +272,77 @@ public final class Locale implements Cloneable, Serializable {
      */
     private static final String UNDETERMINED_LANGUAGE = "und";
 
+
+    /**
+     * Map of grandfathered language tags to their modern replacements.
+     */
+    private static final TreeMap<String, String> GRANDFATHERED_LOCALES;
+
     /**
-     * The current default locale. It is temporarily assigned to US because we
-     * need a default locale to lookup the real default locale.
+     * The default locale, returned by {@code Locale.getDefault()}.
      */
-    private static Locale defaultLocale = US;
+    private static Locale defaultLocale;
 
     static {
-        String language = System.getProperty("user.language", "en");
-        String region = System.getProperty("user.region", "US");
-        String variant = System.getProperty("user.variant", "");
-        defaultLocale = new Locale(language, region, variant);
+        GRANDFATHERED_LOCALES = new TreeMap<String, String>(String.CASE_INSENSITIVE_ORDER);
+
+        // From http://tools.ietf.org/html/bcp47
+        //
+        // grandfathered = irregular           ; non-redundant tags registered
+        //               / regular             ; during the RFC 3066 era
+        //  irregular =
+        GRANDFATHERED_LOCALES.put("en-GB-oed", "en-GB-x-oed");
+        GRANDFATHERED_LOCALES.put("i-ami", "ami");
+        GRANDFATHERED_LOCALES.put("i-bnn", "bnn");
+        GRANDFATHERED_LOCALES.put("i-default", "en-x-i-default");
+        GRANDFATHERED_LOCALES.put("i-enochian", "und-x-i-enochian");
+        GRANDFATHERED_LOCALES.put("i-hak", "hak");
+        GRANDFATHERED_LOCALES.put("i-klingon", "tlh");
+        GRANDFATHERED_LOCALES.put("i-lux", "lb");
+        GRANDFATHERED_LOCALES.put("i-mingo", "see-x-i-mingo");
+        GRANDFATHERED_LOCALES.put("i-navajo", "nv");
+        GRANDFATHERED_LOCALES.put("i-pwn", "pwn");
+        GRANDFATHERED_LOCALES.put("i-tao", "tao");
+        GRANDFATHERED_LOCALES.put("i-tay", "tay");
+        GRANDFATHERED_LOCALES.put("i-tsu", "tsu");
+        GRANDFATHERED_LOCALES.put("sgn-BE-FR", "sfb");
+        GRANDFATHERED_LOCALES.put("sgn-BE-NL", "vgt");
+        GRANDFATHERED_LOCALES.put("sgn-CH-DE", "sgg");
+
+        // regular =
+        GRANDFATHERED_LOCALES.put("art-lojban", "jbo");
+        GRANDFATHERED_LOCALES.put("cel-gaulish", "xtg-x-cel-gaulish");
+        GRANDFATHERED_LOCALES.put("no-bok", "nb");
+        GRANDFATHERED_LOCALES.put("no-nyn", "nn");
+        GRANDFATHERED_LOCALES.put("zh-guoyu", "cmn");
+        GRANDFATHERED_LOCALES.put("zh-hakka", "hak");
+        GRANDFATHERED_LOCALES.put("zh-min", "nan-x-zh-min");
+        GRANDFATHERED_LOCALES.put("zh-min-nan", "nan");
+        GRANDFATHERED_LOCALES.put("zh-xiang", "hsn");
+
+        // Initialize the default locale from the system properties.
+        defaultLocale = getDefaultLocaleFromSystemProperties();
+    }
+
+    /**
+     * Returns the default locale from system properties.
+     *
+     * @hide visible for testing.
+     */
+    public static Locale getDefaultLocaleFromSystemProperties() {
+        final String languageTag = System.getProperty("user.locale", "");
+
+        final Locale defaultLocale;
+        if (!languageTag.isEmpty()) {
+            defaultLocale = Locale.forLanguageTag(languageTag);
+        } else {
+            String language = System.getProperty("user.language", "en");
+            String region = System.getProperty("user.region", "US");
+            String variant = System.getProperty("user.variant", "");
+            defaultLocale = new Locale(language, region, variant);
+        }
+
+        return defaultLocale;
     }
 
     /**
@@ -2020,49 +2080,6 @@ public final class Locale implements Cloneable, Serializable {
         return adjusted;
     }
 
-    /**
-     * Map of grandfathered language tags to their modern replacements.
-     */
-    private static final TreeMap<String, String> GRANDFATHERED_LOCALES;
-
-    static {
-        GRANDFATHERED_LOCALES = new TreeMap<String, String>(String.CASE_INSENSITIVE_ORDER);
-
-        // From http://tools.ietf.org/html/bcp47
-        //
-        // grandfathered = irregular           ; non-redundant tags registered
-        //               / regular             ; during the RFC 3066 era
-        //  irregular =
-        GRANDFATHERED_LOCALES.put("en-GB-oed", "en-GB-x-oed");
-        GRANDFATHERED_LOCALES.put("i-ami", "ami");
-        GRANDFATHERED_LOCALES.put("i-bnn", "bnn");
-        GRANDFATHERED_LOCALES.put("i-default", "en-x-i-default");
-        GRANDFATHERED_LOCALES.put("i-enochian", "und-x-i-enochian");
-        GRANDFATHERED_LOCALES.put("i-hak", "hak");
-        GRANDFATHERED_LOCALES.put("i-klingon", "tlh");
-        GRANDFATHERED_LOCALES.put("i-lux", "lb");
-        GRANDFATHERED_LOCALES.put("i-mingo", "see-x-i-mingo");
-        GRANDFATHERED_LOCALES.put("i-navajo", "nv");
-        GRANDFATHERED_LOCALES.put("i-pwn", "pwn");
-        GRANDFATHERED_LOCALES.put("i-tao", "tao");
-        GRANDFATHERED_LOCALES.put("i-tay", "tay");
-        GRANDFATHERED_LOCALES.put("i-tsu", "tsu");
-        GRANDFATHERED_LOCALES.put("sgn-BE-FR", "sfb");
-        GRANDFATHERED_LOCALES.put("sgn-BE-NL", "vgt");
-        GRANDFATHERED_LOCALES.put("sgn-CH-DE", "sgg");
-
-        // regular =
-        GRANDFATHERED_LOCALES.put("art-lojban", "jbo");
-        GRANDFATHERED_LOCALES.put("cel-gaulish", "xtg-x-cel-gaulish");
-        GRANDFATHERED_LOCALES.put("no-bok", "nb");
-        GRANDFATHERED_LOCALES.put("no-nyn", "nn");
-        GRANDFATHERED_LOCALES.put("zh-guoyu", "cmn");
-        GRANDFATHERED_LOCALES.put("zh-hakka", "hak");
-        GRANDFATHERED_LOCALES.put("zh-min", "nan-x-zh-min");
-        GRANDFATHERED_LOCALES.put("zh-min-nan", "nan");
-        GRANDFATHERED_LOCALES.put("zh-xiang", "hsn");
-    }
-
     private static String convertGrandfatheredTag(String original) {
         final String converted = GRANDFATHERED_LOCALES.get(original);
         return converted != null ? converted : original;
diff --git a/luni/src/test/java/libcore/java/util/LocaleTest.java b/luni/src/test/java/libcore/java/util/LocaleTest.java
index 15e01a1..c6dd730 100644
--- a/luni/src/test/java/libcore/java/util/LocaleTest.java
+++ b/luni/src/test/java/libcore/java/util/LocaleTest.java
@@ -1165,4 +1165,42 @@ public class LocaleTest extends junit.framework.TestCase {
         assertEquals('\u0660', new DecimalFormatSymbols(ar_EG_arab).getZeroDigit());
         assertEquals('0', new DecimalFormatSymbols(ar_EG_latn).getZeroDigit());
     }
+
+    public void testDefaultLocale() throws Exception {
+        final String userLanguage = System.getProperty("user.language", "");
+        final String userRegion = System.getProperty("user.region", "");
+        final String userLocale = System.getProperty("user.locale", "");
+        try {
+            // Assert that user.locale gets priority.
+            System.setProperty("user.locale", "de-DE");
+            System.setProperty("user.language", "en");
+            System.setProperty("user.region", "US");
+
+            Locale l = Locale.getDefaultLocaleFromSystemProperties();
+            assertEquals("de", l.getLanguage());
+            assertEquals("DE", l.getCountry());
+
+            // Assert that it's parsed as a full language tag.
+            System.setProperty("user.locale", "de-Latn-DE");
+            System.setProperty("user.language", "en");
+            System.setProperty("user.region", "US");
+
+            l = Locale.getDefaultLocaleFromSystemProperties();
+            assertEquals("de", l.getLanguage());
+            assertEquals("DE", l.getCountry());
+            assertEquals("Latn", l.getScript());
+
+            // Assert that we use "und" if we're faced with a bad language tag, and
+            // that we don't end up with a null default locale or an exception.
+            System.setProperty("user.locale", "dexx-Latn-DE");
+
+            l = Locale.getDefaultLocaleFromSystemProperties();
+            assertEquals("und", l.getLanguage());
+            assertEquals("DE", l.getCountry());
+        } finally {
+            System.setProperty("user.language", userLanguage);
+            System.setProperty("user.region", userRegion);
+            System.setProperty("user.locale", userLocale);
+        }
+    }
 }