Implement smarter locale resource selection

* Add support for determining script from language and region.
* Add support for determining special parents of locales.
* Add support for smart comparison of locales with only a difference
  in region, using the locale parentage tree.
* Fix LocaleData.matchScore() to not fallback to old locale matching
  behavior if we can't determine a script.
* Allow four-character variant codes. (Previously, only five- to
  eight-character variant codes were allowed.)

Bug: 7296673
Bug: 26589793
Change-Id: Ibde0a48c0564ff383b41068095a5cbacfe7b94bc
diff --git a/libs/androidfw/tests/ConfigLocale_test.cpp b/libs/androidfw/tests/ConfigLocale_test.cpp
index 4999594..1941563 100644
--- a/libs/androidfw/tests/ConfigLocale_test.cpp
+++ b/libs/androidfw/tests/ConfigLocale_test.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <androidfw/LocaleData.h>
 #include <androidfw/ResourceTypes.h>
 #include <utils/Log.h>
 #include <utils/String8.h>
@@ -28,7 +29,7 @@
      EXPECT_EQ('e', config.language[0]);
      EXPECT_EQ('n', config.language[1]);
 
-     char out[4] = { 1, 1, 1, 1};
+     char out[4] = {1, 1, 1, 1};
      config.unpackLanguage(out);
      EXPECT_EQ('e', out[0]);
      EXPECT_EQ('n', out[1]);
@@ -51,7 +52,7 @@
      EXPECT_EQ('U', config.country[0]);
      EXPECT_EQ('S', config.country[1]);
 
-     char out[4] = { 1, 1, 1, 1};
+     char out[4] = {1, 1, 1, 1};
      config.unpackRegion(out);
      EXPECT_EQ('U', out[0]);
      EXPECT_EQ('S', out[1]);
@@ -67,7 +68,7 @@
      EXPECT_EQ('\x99', config.language[0]);
      EXPECT_EQ('\xA4', config.language[1]);
 
-     char out[4] = { 1, 1, 1, 1};
+     char out[4] = {1, 1, 1, 1};
      config.unpackLanguage(out);
      EXPECT_EQ('e', out[0]);
      EXPECT_EQ('n', out[1]);
@@ -91,7 +92,7 @@
      EXPECT_EQ(char(0xbc), config.language[0]);
      EXPECT_EQ(char(0xd3), config.language[1]);
 
-     char out[4] = { 1, 1, 1, 1};
+     char out[4] = {1, 1, 1, 1};
      config.unpackLanguage(out);
      EXPECT_EQ('t', out[0]);
      EXPECT_EQ('g', out[1]);
@@ -103,7 +104,7 @@
      ResTable_config config;
      config.packRegion("419");
 
-     char out[4] = { 1, 1, 1, 1};
+     char out[4] = {1, 1, 1, 1};
      config.unpackRegion(out);
 
      EXPECT_EQ('4', out[0]);
@@ -124,6 +125,10 @@
 
      if (script != NULL) {
          memcpy(out->localeScript, script, 4);
+         out->localeScriptWasProvided = true;
+     } else {
+         out->computeScript();
+         out->localeScriptWasProvided = false;
      }
 
      if (variant != NULL) {
@@ -177,11 +182,12 @@
     EXPECT_EQ('n', test.language[1]);
     EXPECT_EQ('U', test.country[0]);
     EXPECT_EQ('S', test.country[1]);
-    EXPECT_EQ(0, test.localeScript[0]);
+    EXPECT_FALSE(test.localeScriptWasProvided);
+    EXPECT_EQ(0, memcmp("Latn", test.localeScript, 4));
     EXPECT_EQ(0, test.localeVariant[0]);
 
     test.setBcp47Locale("eng-419");
-    char out[4] = { 1, 1, 1, 1};
+    char out[4] = {1, 1, 1, 1};
     test.unpackLanguage(out);
     EXPECT_EQ('e', out[0]);
     EXPECT_EQ('n', out[1]);
@@ -193,17 +199,397 @@
     EXPECT_EQ('1', out[1]);
     EXPECT_EQ('9', out[2]);
 
-
     test.setBcp47Locale("en-Latn-419");
-    memset(out, 1, 4);
     EXPECT_EQ('e', test.language[0]);
     EXPECT_EQ('n', test.language[1]);
-
     EXPECT_EQ(0, memcmp("Latn", test.localeScript, 4));
+    EXPECT_TRUE(test.localeScriptWasProvided);
+    memset(out, 1, 4);
     test.unpackRegion(out);
     EXPECT_EQ('4', out[0]);
     EXPECT_EQ('1', out[1]);
     EXPECT_EQ('9', out[2]);
+
+    test.setBcp47Locale("de-1901");
+    memset(out, 1, 4);
+    test.unpackLanguage(out);
+    EXPECT_EQ('d', out[0]);
+    EXPECT_EQ('e', out[1]);
+    EXPECT_EQ('\0', out[2]);
+    EXPECT_FALSE(test.localeScriptWasProvided);
+    EXPECT_EQ(0, memcmp("Latn", test.localeScript, 4));
+    memset(out, 1, 4);
+    test.unpackRegion(out);
+    EXPECT_EQ('\0', out[0]);
+    EXPECT_EQ(0, strcmp("1901", test.localeVariant));
+
+    test.setBcp47Locale("de-Latn-1901");
+    memset(out, 1, 4);
+    test.unpackLanguage(out);
+    EXPECT_EQ('d', out[0]);
+    EXPECT_EQ('e', out[1]);
+    EXPECT_EQ('\0', out[2]);
+    EXPECT_TRUE(test.localeScriptWasProvided);
+    EXPECT_EQ(0, memcmp("Latn", test.localeScript, 4));
+    memset(out, 1, 4);
+    test.unpackRegion(out);
+    EXPECT_EQ('\0', out[0]);
+    EXPECT_EQ(0, strcmp("1901", test.localeVariant));
 }
 
-}  // namespace android.
+TEST(ConfigLocaleTest, computeScript) {
+    ResTable_config config;
+
+    fillIn(NULL, NULL, NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("\0\0\0\0", config.localeScript, 4));
+
+    fillIn("zh", "TW", NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("Hant", config.localeScript, 4));
+
+    fillIn("zh", "CN", NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("Hans", config.localeScript, 4));
+
+    fillIn("az", NULL, NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("Latn", config.localeScript, 4));
+
+    fillIn("az", "AZ", NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("Latn", config.localeScript, 4));
+
+    fillIn("az", "IR", NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("Arab", config.localeScript, 4));
+
+    fillIn("peo", NULL, NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("Xpeo", config.localeScript, 4));
+
+    fillIn("qaa", NULL, NULL, NULL, &config);
+    EXPECT_EQ(0, memcmp("\0\0\0\0", config.localeScript, 4));
+}
+
+TEST(ConfigLocaleTest, getBcp47Locale_script) {
+    ResTable_config config;
+    fillIn("en", NULL, "Latn", NULL, &config);
+
+    char out[RESTABLE_MAX_LOCALE_LEN];
+    config.localeScriptWasProvided = true;
+    config.getBcp47Locale(out);
+    EXPECT_EQ(0, strcmp("en-Latn", out));
+
+    config.localeScriptWasProvided = false;
+    config.getBcp47Locale(out);
+    EXPECT_EQ(0, strcmp("en", out));
+}
+
+TEST(ConfigLocaleTest, match) {
+    ResTable_config supported, requested;
+
+    fillIn(NULL, NULL, NULL, NULL, &supported);
+    fillIn("fr", "CA", NULL, NULL, &requested);
+    // Empty locale matches everything (as a default).
+    EXPECT_TRUE(supported.match(requested));
+
+    fillIn("en", "CA", NULL, NULL, &supported);
+    fillIn("fr", "CA", NULL, NULL, &requested);
+    // Different languages don't match.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("qaa", "FR", NULL, NULL, &supported);
+    fillIn("qaa", "CA", NULL, NULL, &requested);
+    // If we can't infer the scripts, different regions don't match.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("qaa", "FR", "Latn", NULL, &supported);
+    fillIn("qaa", "CA", NULL, NULL, &requested);
+    // If we can't infer any of the scripts, different regions don't match.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("qaa", "FR", NULL, NULL, &supported);
+    fillIn("qaa", "CA", "Latn", NULL, &requested);
+    // If we can't infer any of the scripts, different regions don't match.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("qaa", NULL, NULL, NULL, &supported);
+    fillIn("qaa", "CA", NULL, NULL, &requested);
+    // language-only resources still support language+region requests, even if we can't infer the
+    // script.
+    EXPECT_TRUE(supported.match(requested));
+
+    fillIn("qaa", "CA", NULL, NULL, &supported);
+    fillIn("qaa", "CA", NULL, NULL, &requested);
+    // Even if we can't infer the scripts, exactly equal locales match.
+    EXPECT_TRUE(supported.match(requested));
+
+    fillIn("az", NULL, NULL, NULL, &supported);
+    fillIn("az", NULL, "Latn", NULL, &requested);
+    // If the resolved scripts are the same, it doesn't matter if they were explicitly provided
+    // or not, and they match.
+    EXPECT_TRUE(supported.match(requested));
+
+    fillIn("az", NULL, NULL, NULL, &supported);
+    fillIn("az", NULL, "Cyrl", NULL, &requested);
+    // If the resolved scripts are different, they don't match.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("az", NULL, NULL, NULL, &supported);
+    fillIn("az", "IR", NULL, NULL, &requested);
+    // If the resolved scripts are different, they don't match.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("az", "IR", NULL, NULL, &supported);
+    fillIn("az", NULL, "Arab", NULL, &requested);
+    // If the resolved scripts are the same, it doesn't matter if they were explicitly provided
+    // or not, and they match.
+    EXPECT_TRUE(supported.match(requested));
+
+    fillIn("en", NULL, NULL, NULL, &supported);
+    fillIn("en", "XA", NULL, NULL, &requested);
+    // en-XA is a pseudo-locale, and English resources are not a match for it.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("en", "XA", NULL, NULL, &supported);
+    fillIn("en", NULL, NULL, NULL, &requested);
+    // en-XA is a pseudo-locale, and its resources don't support English locales.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("en", "XA", NULL, NULL, &supported);
+    fillIn("en", "XA", NULL, NULL, &requested);
+    // Even if they are pseudo-locales, exactly equal locales match.
+    EXPECT_TRUE(supported.match(requested));
+
+    fillIn("ar", NULL, NULL, NULL, &supported);
+    fillIn("ar", "XB", NULL, NULL, &requested);
+    // ar-XB is a pseudo-locale, and Arabic resources are not a match for it.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("ar", "XB", NULL, NULL, &supported);
+    fillIn("ar", NULL, NULL, NULL, &requested);
+    // ar-XB is a pseudo-locale, and its resources don't support Arabic locales.
+    EXPECT_FALSE(supported.match(requested));
+
+    fillIn("ar", "XB", NULL, NULL, &supported);
+    fillIn("ar", "XB", NULL, NULL, &requested);
+    // Even if they are pseudo-locales, exactly equal locales match.
+    EXPECT_TRUE(supported.match(requested));
+}
+
+TEST(ConfigLocaleTest, isLocaleBetterThan_basics) {
+    ResTable_config config1, config2, request;
+
+    fillIn(NULL, NULL, NULL, NULL, &request);
+    fillIn("fr", "FR", NULL, NULL, &config1);
+    fillIn("fr", "CA", NULL, NULL, &config2);
+    EXPECT_FALSE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("fr", "CA", NULL, NULL, &request);
+    fillIn(NULL, NULL, NULL, NULL, &config1);
+    fillIn(NULL, NULL, NULL, NULL, &config2);
+    EXPECT_FALSE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("fr", "CA", NULL, NULL, &request);
+    fillIn("fr", "FR", NULL, NULL, &config1);
+    fillIn(NULL, NULL, NULL, NULL, &config2);
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("de", "DE", NULL, NULL, &request);
+    fillIn("de", "DE", NULL, "1901", &config1);
+    fillIn("de", "DE", NULL, "1996", &config2);
+    EXPECT_FALSE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("de", "DE", NULL, "1901", &request);
+    fillIn("de", "DE", NULL, "1901", &config1);
+    fillIn("de", "DE", NULL, NULL, &config2);
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("de", "DE", NULL, "1901", &request);
+    fillIn("de", "DE", NULL, "1996", &config1);
+    fillIn("de", "DE", NULL, NULL, &config2);
+    EXPECT_FALSE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+}
+
+TEST(ConfigLocaleTest, isLocaleBetterThan_regionComparison) {
+    ResTable_config config1, config2, request;
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "419", NULL, NULL, &config1);
+    fillIn("es", "419", NULL, NULL, &config2);
+    // Both supported locales are the same, so none is better than the other.
+    EXPECT_FALSE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "AR", NULL, NULL, &config1);
+    fillIn("es", "419", NULL, NULL, &config2);
+    // An exact locale match is better than a parent.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "419", NULL, NULL, &config1);
+    fillIn("es", NULL, NULL, NULL, &config2);
+    // A closer parent is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "419", NULL, NULL, &config1);
+    fillIn("es", "ES", NULL, NULL, &config2);
+    // A parent is better than a non-parent representative locale.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", NULL, NULL, NULL, &config1);
+    fillIn("es", "ES", NULL, NULL, &config2);
+    // A parent is better than a non-parent representative locale.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "PE", NULL, NULL, &config1);
+    fillIn("es", "ES", NULL, NULL, &config2);
+    // A closer locale is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "MX", NULL, NULL, &config1);
+    fillIn("es", "BO", NULL, NULL, &config2);
+    // A representative locale is better if they are equidistant.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "US", NULL, NULL, &config1);
+    fillIn("es", "BO", NULL, NULL, &config2);
+    // A representative locale is better if they are equidistant.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "AR", NULL, NULL, &request);
+    fillIn("es", "MX", NULL, NULL, &config1);
+    fillIn("es", "US", NULL, NULL, &config2);
+    // If all is equal, the locale earlier in the dictionary is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("es", "GQ", NULL, NULL, &request);
+    fillIn("es", "IC", NULL, NULL, &config1);
+    fillIn("es", "419", NULL, NULL, &config2);
+    // If all is equal, the locale earlier in the dictionary is better and
+    // letters are better than numbers.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "GB", NULL, NULL, &request);
+    fillIn("en", "001", NULL, NULL, &config1);
+    fillIn("en", NULL, NULL, NULL, &config2);
+    // A closer parent is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "PR", NULL, NULL, &request);
+    fillIn("en", NULL, NULL, NULL, &config1);
+    fillIn("en", "001", NULL, NULL, &config2);
+    // A parent is better than a non-parent.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "DE", NULL, NULL, &request);
+    fillIn("en", "150", NULL, NULL, &config1);
+    fillIn("en", "001", NULL, NULL, &config2);
+    // A closer parent is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "IN", NULL, NULL, &request);
+    fillIn("en", "AU", NULL, NULL, &config1);
+    fillIn("en", "US", NULL, NULL, &config2);
+    // A closer locale is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "PR", NULL, NULL, &request);
+    fillIn("en", "001", NULL, NULL, &config1);
+    fillIn("en", "GB", NULL, NULL, &config2);
+    // A closer locale is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "IN", NULL, NULL, &request);
+    fillIn("en", "GB", NULL, NULL, &config1);
+    fillIn("en", "AU", NULL, NULL, &config2);
+    // A representative locale is better if they are equidistant.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("en", "IN", NULL, NULL, &request);
+    fillIn("en", "AU", NULL, NULL, &config1);
+    fillIn("en", "CA", NULL, NULL, &config2);
+    // If all is equal, the locale earlier in the dictionary is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("pt", "MZ", NULL, NULL, &request);
+    fillIn("pt", "PT", NULL, NULL, &config1);
+    fillIn("pt", NULL, NULL, NULL, &config2);
+    // A closer parent is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("pt", "MZ", NULL, NULL, &request);
+    fillIn("pt", "PT", NULL, NULL, &config1);
+    fillIn("pt", "BR", NULL, NULL, &config2);
+    // A parent is better than a non-parent.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("zh", "MO", "Hant", NULL, &request);
+    fillIn("zh", "HK", "Hant", NULL, &config1);
+    fillIn("zh", "TW", "Hant", NULL, &config2);
+    // A parent is better than a non-parent.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("zh", "US", "Hant", NULL, &request);
+    fillIn("zh", "TW", "Hant", NULL, &config1);
+    fillIn("zh", "HK", "Hant", NULL, &config2);
+    // A representative locale is better if they are equidistant.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("ar", "DZ", NULL, NULL, &request);
+    fillIn("ar", "015", NULL, NULL, &config1);
+    fillIn("ar", NULL, NULL, NULL, &config2);
+    // A closer parent is better.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("ar", "EG", NULL, NULL, &request);
+    fillIn("ar", NULL, NULL, NULL, &config1);
+    fillIn("ar", "015", NULL, NULL, &config2);
+    // A parent is better than a non-parent.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("ar", "QA", NULL, NULL, &request);
+    fillIn("ar", "EG", NULL, NULL, &config1);
+    fillIn("ar", "BH", NULL, NULL, &config2);
+    // A representative locale is better if they are equidistant.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+
+    fillIn("ar", "QA", NULL, NULL, &request);
+    fillIn("ar", "SA", NULL, NULL, &config1);
+    fillIn("ar", "015", NULL, NULL, &config2);
+    // If all is equal, the locale earlier in the dictionary is better and
+    // letters are better than numbers.
+    EXPECT_TRUE(config1.isLocaleBetterThan(config2, &request));
+    EXPECT_FALSE(config2.isLocaleBetterThan(config1, &request));
+}
+
+}  // namespace android