diff --git a/core/java/android/content/res/AssetManager.java b/core/java/android/content/res/AssetManager.java
index 7669053..ee6aec2 100644
--- a/core/java/android/content/res/AssetManager.java
+++ b/core/java/android/content/res/AssetManager.java
@@ -698,6 +698,18 @@
      */
     public native final String[] getLocales();
 
+    /**
+     * Same as getLocales(), except that locales that are only provided by the system (i.e. those
+     * present in framework-res.apk or its overlays) will not be listed.
+     *
+     * For example, if the "system" assets support English, French, and German, and the additional
+     * assets support Cherokee and French, getLocales() would return
+     * [Cherokee, English, French, German], while getNonSystemLocales() would return
+     * [Cherokee, French].
+     * {@hide}
+     */
+    public native final String[] getNonSystemLocales();
+
     /** {@hide} */
     public native final Configuration[] getSizeConfigurations();
 
diff --git a/core/java/android/content/res/Resources.java b/core/java/android/content/res/Resources.java
index 60c6e82..c460746 100644
--- a/core/java/android/content/res/Resources.java
+++ b/core/java/android/content/res/Resources.java
@@ -1976,7 +1976,21 @@
 
             if (setLocalesToDefault || mResolvedLocale == null
                     || (configChanges & Configuration.NATIVE_CONFIG_LOCALE) != 0) {
-                mResolvedLocale = locales.getFirstMatch(mAssets.getLocales());
+                if (locales.size() == 1) {
+                    // This is an optimization to avoid the JNI call(s) when the result of
+                    // getFirstMatch() does not depend on the supported locales.
+                    mResolvedLocale = locales.getPrimary();
+                } else {
+                    String[] supportedLocales = mAssets.getNonSystemLocales();
+                    if (LocaleList.isPseudoLocalesOnly(supportedLocales)) {
+                        // We fallback to all locales (including system locales) if there was no
+                        // locale specifically supported by the assets. This is to properly support
+                        // apps that only rely on the shared system assets and don't need assets of
+                        // their own.
+                        supportedLocales = mAssets.getLocales();
+                    }
+                    mResolvedLocale = locales.getFirstMatch(supportedLocales);
+                }
             }
             mAssets.setConfiguration(mConfiguration.mcc, mConfiguration.mnc,
                     adjustLanguageTag(mResolvedLocale.toLanguageTag()),
diff --git a/core/java/android/util/LocaleList.java b/core/java/android/util/LocaleList.java
index 1becfb4..65a436b 100644
--- a/core/java/android/util/LocaleList.java
+++ b/core/java/android/util/LocaleList.java
@@ -219,6 +219,20 @@
         }
     }
 
+    private static final String STRING_EN_XA = "en-XA";
+    private static final String STRING_AR_XB = "ar-XB";
+    private static final Locale LOCALE_EN_XA = new Locale("en", "XA");
+    private static final Locale LOCALE_AR_XB = new Locale("ar", "XB");
+    private static final int NUM_PSEUDO_LOCALES = 2;
+
+    private static boolean isPseudoLocale(String locale) {
+        return STRING_EN_XA.equals(locale) || STRING_AR_XB.equals(locale);
+    }
+
+    private static boolean isPseudoLocale(Locale locale) {
+        return LOCALE_EN_XA.equals(locale) || LOCALE_AR_XB.equals(locale);
+    }
+
     private static int matchScore(Locale supported, Locale desired) {
         if (supported.equals(desired)) {
             return 1;  // return early so we don't do unnecessary computation
@@ -226,6 +240,11 @@
         if (!supported.getLanguage().equals(desired.getLanguage())) {
             return 0;
         }
+        if (isPseudoLocale(supported) || isPseudoLocale(desired)) {
+            // The locales are not the same, but the languages are the same, and one of the locales
+            // is a pseudo-locale. So this is not a match.
+            return 0;
+        }
         // There is no match if the two locales use different scripts. This will most imporantly
         // take care of traditional vs simplified Chinese.
         final String supportedScr = getLikelyScript(supported);
@@ -247,7 +266,6 @@
         if (mList.length == 0) {  // empty locale list
             return null;
         }
-        // TODO: Figure out what to if en-XA or ar-XB are in the locale list
         int bestIndex = Integer.MAX_VALUE;
         for (String tag : supportedLocales) {
             final Locale supportedLocale = Locale.forLanguageTag(tag);
@@ -271,6 +289,27 @@
         }
     }
 
+    /**
+     * Returns true if the array of locale tags only contains empty locales and pseudolocales.
+     * Assumes that there is no repetition in the input.
+     * {@hide}
+     */
+    public static boolean isPseudoLocalesOnly(String[] supportedLocales) {
+        if (supportedLocales.length > NUM_PSEUDO_LOCALES + 1) {
+            // This is for optimization. Since there's no repetition in the input, if we have more
+            // than the number of pseudo-locales plus one for the empty string, it's guaranteed
+            // that we have some meaninful locale in the list, so the list is not "practically
+            // empty".
+            return false;
+        }
+        for (String locale : supportedLocales) {
+            if (!locale.isEmpty() && !isPseudoLocale(locale)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
     private final static Object sLock = new Object();
 
     @GuardedBy("sLock")
diff --git a/core/jni/android_util_AssetManager.cpp b/core/jni/android_util_AssetManager.cpp
index 90606a35..3473d9d 100644
--- a/core/jni/android_util_AssetManager.cpp
+++ b/core/jni/android_util_AssetManager.cpp
@@ -578,7 +578,7 @@
     return am->isUpToDate() ? JNI_TRUE : JNI_FALSE;
 }
 
-static jobjectArray android_content_AssetManager_getLocales(JNIEnv* env, jobject clazz)
+static jobjectArray getLocales(JNIEnv* env, jobject clazz, bool includeSystemLocales)
 {
     Vector<String8> locales;
 
@@ -587,7 +587,7 @@
         return NULL;
     }
 
-    am->getLocales(&locales);
+    am->getLocales(&locales, includeSystemLocales);
 
     const int N = locales.size();
 
@@ -608,6 +608,16 @@
     return result;
 }
 
+static jobjectArray android_content_AssetManager_getLocales(JNIEnv* env, jobject clazz)
+{
+    return getLocales(env, clazz, true /* include system locales */);
+}
+
+static jobjectArray android_content_AssetManager_getNonSystemLocales(JNIEnv* env, jobject clazz)
+{
+    return getLocales(env, clazz, false /* don't include system locales */);
+}
+
 static jobject constructConfigurationObject(JNIEnv* env, const ResTable_config& config) {
     jobject result = env->NewObject(gConfigurationOffsets.classObject,
             gConfigurationOffsets.constructor);
@@ -2154,6 +2164,8 @@
     // Resources.
     { "getLocales",      "()[Ljava/lang/String;",
         (void*) android_content_AssetManager_getLocales },
+    { "getNonSystemLocales", "()[Ljava/lang/String;",
+        (void*) android_content_AssetManager_getNonSystemLocales },
     { "getSizeConfigurations", "()[Landroid/content/res/Configuration;",
         (void*) android_content_AssetManager_getSizeConfigurations },
     { "setConfiguration", "!(IILjava/lang/String;IIIIIIIIIIIIII)V",
diff --git a/include/androidfw/AssetManager.h b/include/androidfw/AssetManager.h
index 3d4e47d..914ac3d 100644
--- a/include/androidfw/AssetManager.h
+++ b/include/androidfw/AssetManager.h
@@ -100,16 +100,17 @@
      * then on success, *cookie is set to the value corresponding to the
      * newly-added asset source.
      */
-    bool addAssetPath(const String8& path, int32_t* cookie, bool appAsLib=false);
+    bool addAssetPath(const String8& path, int32_t* cookie,
+        bool appAsLib=false, bool isSystemAsset=false);
     bool addOverlayPath(const String8& path, int32_t* cookie);
 
-    /*                                                                       
+    /*
      * Convenience for adding the standard system assets.  Uses the
      * ANDROID_ROOT environment variable to find them.
      */
     bool addDefaultAssets();
 
-    /*                                                                       
+    /*
      * Iterate over the asset paths in this manager.  (Previously
      * added via addAssetPath() and addDefaultAssets().)  On first call,
      * 'cookie' must be 0, resulting in the first cookie being returned.
@@ -118,7 +119,7 @@
      */
     int32_t nextAssetPath(const int32_t cookie) const;
 
-    /*                                                                       
+    /*
      * Return an asset path in the manager.  'which' must be between 0 and
      * countAssetPaths().
      */
@@ -221,11 +222,11 @@
      * the current data.
      */
     bool isUpToDate();
-    
+
     /**
      * Get the known locales for this asset manager object.
      */
-    void getLocales(Vector<String8>* locales) const;
+    void getLocales(Vector<String8>* locales, bool includeSystemLocales=true) const;
 
     /**
      * Generate idmap data to translate resources IDs between a package and a
@@ -237,11 +238,13 @@
 private:
     struct asset_path
     {
-        asset_path() : path(""), type(kFileTypeRegular), idmap(""), isSystemOverlay(false) {}
+        asset_path() : path(""), type(kFileTypeRegular), idmap(""),
+                       isSystemOverlay(false), isSystemAsset(false) {}
         String8 path;
         FileType type;
         String8 idmap;
         bool isSystemOverlay;
+        bool isSystemAsset;
     };
 
     Asset* openInPathLocked(const char* fileName, AccessMode mode,
diff --git a/include/androidfw/ResourceTypes.h b/include/androidfw/ResourceTypes.h
index 49b6333..428a2b8 100644
--- a/include/androidfw/ResourceTypes.h
+++ b/include/androidfw/ResourceTypes.h
@@ -1552,9 +1552,9 @@
 
     status_t add(Asset* asset, const int32_t cookie=-1, bool copyData=false);
     status_t add(Asset* asset, Asset* idmapAsset, const int32_t cookie=-1, bool copyData=false,
-            bool appAsLib=false);
+            bool appAsLib=false, bool isSystemAsset=false);
 
-    status_t add(ResTable* src);
+    status_t add(ResTable* src, bool isSystemAsset=false);
     status_t addEmpty(const int32_t cookie);
 
     status_t getError() const;
@@ -1822,9 +1822,9 @@
 
     // Return the configurations (ResTable_config) that we know about
     void getConfigurations(Vector<ResTable_config>* configs, bool ignoreMipmap=false,
-            bool ignoreAndroidPackage=false) const;
+            bool ignoreAndroidPackage=false, bool includeSystemConfigs=true) const;
 
-    void getLocales(Vector<String8>* locales) const;
+    void getLocales(Vector<String8>* locales, bool includeSystemLocales=true) const;
 
     // Generate an idmap.
     //
@@ -1860,7 +1860,7 @@
     typedef Vector<Type*> TypeList;
 
     status_t addInternal(const void* data, size_t size, const void* idmapData, size_t idmapDataSize,
-            bool appAsLib, const int32_t cookie, bool copyData);
+            bool appAsLib, const int32_t cookie, bool copyData, bool isSystemAsset=false);
 
     ssize_t getResourcePackageIndex(uint32_t resID) const;
 
@@ -1873,10 +1873,11 @@
             size_t nameLen, uint32_t* outTypeSpecFlags) const;
 
     status_t parsePackage(
-        const ResTable_package* const pkg, const Header* const header, bool appAsLib);
+        const ResTable_package* const pkg, const Header* const header,
+        bool appAsLib, bool isSystemAsset);
 
     void print_value(const Package* pkg, const Res_value& value) const;
-    
+
     mutable Mutex               mLock;
 
     status_t                    mError;
diff --git a/libs/androidfw/AssetManager.cpp b/libs/androidfw/AssetManager.cpp
index 8a03b94..6913f43 100644
--- a/libs/androidfw/AssetManager.cpp
+++ b/libs/androidfw/AssetManager.cpp
@@ -176,7 +176,8 @@
     delete[] mVendor;
 }
 
-bool AssetManager::addAssetPath(const String8& path, int32_t* cookie, bool appAsLib)
+bool AssetManager::addAssetPath(
+        const String8& path, int32_t* cookie, bool appAsLib, bool isSystemAsset)
 {
     AutoMutex _l(mLock);
 
@@ -222,6 +223,7 @@
     }
     delete manifestAsset;
 
+    ap.isSystemAsset = isSystemAsset;
     mAssetPaths.add(ap);
 
     // new paths are always added at the end
@@ -233,6 +235,7 @@
     // Load overlays, if any
     asset_path oap;
     for (size_t idx = 0; mZipSet.getOverlay(ap.path, idx, &oap); idx++) {
+        oap.isSystemAsset = isSystemAsset;
         mAssetPaths.add(oap);
     }
 #endif
@@ -340,7 +343,7 @@
     String8 path(root);
     path.appendPath(kSystemAssets);
 
-    return addAssetPath(path, NULL);
+    return addAssetPath(path, NULL, false /* appAsLib */, true /* isSystemAsset */);
 }
 
 int32_t AssetManager::nextAssetPath(const int32_t cookie) const
@@ -682,10 +685,10 @@
         ALOGV("Installing resource asset %p in to table %p\n", ass, mResources);
         if (sharedRes != NULL) {
             ALOGV("Copying existing resources for %s", ap.path.string());
-            mResources->add(sharedRes);
+            mResources->add(sharedRes, ap.isSystemAsset);
         } else {
             ALOGV("Parsing resources for %s", ap.path.string());
-            mResources->add(ass, idmap, nextEntryIdx + 1, !shared, appAsLib);
+            mResources->add(ass, idmap, nextEntryIdx + 1, !shared, appAsLib, ap.isSystemAsset);
         }
         onlyEmptyResources = false;
 
@@ -831,11 +834,11 @@
     return mZipSet.isUpToDate();
 }
 
-void AssetManager::getLocales(Vector<String8>* locales) const
+void AssetManager::getLocales(Vector<String8>* locales, bool includeSystemLocales) const
 {
     ResTable* res = mResources;
     if (res != NULL) {
-        res->getLocales(locales);
+        res->getLocales(locales, includeSystemLocales);
     }
 
     const size_t numLocales = locales->size();
diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index 21b543e..44f92c7 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -3080,13 +3080,16 @@
 // table that defined the package); the ones after are skins on top of it.
 struct ResTable::PackageGroup
 {
-    PackageGroup(ResTable* _owner, const String16& _name, uint32_t _id, bool appAsLib)
+    PackageGroup(
+            ResTable* _owner, const String16& _name, uint32_t _id,
+            bool appAsLib, bool _isSystemAsset)
         : owner(_owner)
         , name(_name)
         , id(_id)
         , largestTypeId(0)
         , bags(NULL)
         , dynamicRefTable(static_cast<uint8_t>(_id), appAsLib)
+        , isSystemAsset(_isSystemAsset)
     { }
 
     ~PackageGroup() {
@@ -3178,6 +3181,10 @@
     // by having these tables in a per-package scope rather than
     // per-package-group.
     DynamicRefTable                 dynamicRefTable;
+
+    // If the package group comes from a system asset. Used in
+    // determining non-system locales.
+    const bool                      isSystemAsset;
 };
 
 struct ResTable::bag_set
@@ -3572,8 +3579,9 @@
             copyData);
 }
 
-status_t ResTable::add(Asset* asset, Asset* idmapAsset, const int32_t cookie, bool copyData,
-        bool appAsLib) {
+status_t ResTable::add(
+        Asset* asset, Asset* idmapAsset, const int32_t cookie, bool copyData,
+        bool appAsLib, bool isSystemAsset) {
     const void* data = asset->getBuffer(true);
     if (data == NULL) {
         ALOGW("Unable to get buffer of resource asset file");
@@ -3592,20 +3600,21 @@
     }
 
     return addInternal(data, static_cast<size_t>(asset->getLength()),
-            idmapData, idmapSize, appAsLib, cookie, copyData);
+            idmapData, idmapSize, appAsLib, cookie, copyData, isSystemAsset);
 }
 
-status_t ResTable::add(ResTable* src)
+status_t ResTable::add(ResTable* src, bool isSystemAsset)
 {
     mError = src->mError;
 
-    for (size_t i=0; i<src->mHeaders.size(); i++) {
+    for (size_t i=0; i < src->mHeaders.size(); i++) {
         mHeaders.add(src->mHeaders[i]);
     }
 
-    for (size_t i=0; i<src->mPackageGroups.size(); i++) {
+    for (size_t i=0; i < src->mPackageGroups.size(); i++) {
         PackageGroup* srcPg = src->mPackageGroups[i];
-        PackageGroup* pg = new PackageGroup(this, srcPg->name, srcPg->id, false);
+        PackageGroup* pg = new PackageGroup(this, srcPg->name, srcPg->id,
+                false /* appAsLib */, isSystemAsset || srcPg->isSystemAsset);
         for (size_t j=0; j<srcPg->packages.size(); j++) {
             pg->packages.add(srcPg->packages[j]);
         }
@@ -3646,7 +3655,7 @@
 }
 
 status_t ResTable::addInternal(const void* data, size_t dataSize, const void* idmapData, size_t idmapDataSize,
-        bool appAsLib, const int32_t cookie, bool copyData)
+        bool appAsLib, const int32_t cookie, bool copyData, bool isSystemAsset)
 {
     if (!data) {
         return NO_ERROR;
@@ -3749,7 +3758,8 @@
                 return (mError=BAD_TYPE);
             }
 
-            if (parsePackage((ResTable_package*)chunk, header, appAsLib) != NO_ERROR) {
+            if (parsePackage(
+                    (ResTable_package*)chunk, header, appAsLib, isSystemAsset) != NO_ERROR) {
                 return mError;
             }
             curPackage++;
@@ -5663,7 +5673,7 @@
 }
 
 void ResTable::getConfigurations(Vector<ResTable_config>* configs, bool ignoreMipmap,
-        bool ignoreAndroidPackage) const {
+        bool ignoreAndroidPackage, bool includeSystemConfigs) const {
     const size_t packageCount = mPackageGroups.size();
     String16 android("android");
     for (size_t i = 0; i < packageCount; i++) {
@@ -5671,6 +5681,9 @@
         if (ignoreAndroidPackage && android == packageGroup->name) {
             continue;
         }
+        if (!includeSystemConfigs && packageGroup->isSystemAsset) {
+            continue;
+        }
         const size_t typeCount = packageGroup->types.size();
         for (size_t j = 0; j < typeCount; j++) {
             const TypeList& typeList = packageGroup->types[j];
@@ -5707,11 +5720,14 @@
     }
 }
 
-void ResTable::getLocales(Vector<String8>* locales) const
+void ResTable::getLocales(Vector<String8>* locales, bool includeSystemLocales) const
 {
     Vector<ResTable_config> configs;
     ALOGV("calling getConfigurations");
-    getConfigurations(&configs);
+    getConfigurations(&configs,
+            false /* ignoreMipmap */,
+            false /* ignoreAndroidPackage */,
+            includeSystemLocales /* includeSystemConfigs */);
     ALOGV("called getConfigurations size=%d", (int)configs.size());
     const size_t I = configs.size();
 
@@ -5937,7 +5953,7 @@
 }
 
 status_t ResTable::parsePackage(const ResTable_package* const pkg,
-                                const Header* const header, bool appAsLib)
+                                const Header* const header, bool appAsLib, bool isSystemAsset)
 {
     const uint8_t* base = (const uint8_t*)pkg;
     status_t err = validate_chunk(&pkg->header, sizeof(*pkg) - sizeof(pkg->typeIdOffset),
@@ -5985,8 +6001,8 @@
     if (id >= 256) {
         LOG_ALWAYS_FATAL("Package id out of range");
         return NO_ERROR;
-    } else if (id == 0 || appAsLib) {
-        // This is a library so assign an ID
+    } else if (id == 0 || appAsLib || isSystemAsset) {
+        // This is a library or a system asset, so assign an ID
         id = mNextPackageId++;
     }
 
@@ -6018,7 +6034,7 @@
 
         char16_t tmpName[sizeof(pkg->name)/sizeof(pkg->name[0])];
         strcpy16_dtoh(tmpName, pkg->name, sizeof(pkg->name)/sizeof(pkg->name[0]));
-        group = new PackageGroup(this, String16(tmpName), id, appAsLib);
+        group = new PackageGroup(this, String16(tmpName), id, appAsLib, isSystemAsset);
         if (group == NULL) {
             delete package;
             return (mError=NO_MEMORY);