Bug 1105316 - Look in Gecko chrome registry for fallback locale in search activity. r=rnewman

--HG--
extra : rebase_source : 42e908cf3c6d08cb8a108d6f7b11b169ef3ab0dd

mobile/android/base/util/GeckoJarReader.java

@@ -110,6 +110,7 @@ public final class GeckoJarReader {
             // Some JNI code throws IllegalArgumentException on a bad file name;
             // swallow the error and return null.  We could also see legitimate
             // IOExceptions here.
+            Log.e(LOGTAG, "Exception getting input stream from jar URL: " + url, ex);
             return null;
         }
     }

mobile/android/search/java/org/mozilla/search/providers/SearchEngineManager.java

@@ -31,6 +31,7 @@ import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
+import java.io.UnsupportedEncodingException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -49,6 +50,10 @@ public class SearchEngineManager implements SharedPreferences.OnSharedPreference
     private SearchEngineCallback changeCallback;
     private SearchEngine engine;
 
+    // Cached version of default locale included in Gecko chrome manifest.
+    // This should only be accessed from the background thread.
+    private String fallbackLocale;
+
     public static interface SearchEngineCallback {
         public void execute(SearchEngine engine);
     }
@@ -309,11 +314,9 @@ public class SearchEngineManager implements SharedPreferences.OnSharedPreference
      */
     private SearchEngine createEngineFromLocale(String name) {
         final InputStream in = getInputStreamFromSearchPluginsJar("list.txt");
-        InputStreamReader isr = null;
+        final BufferedReader br = getBufferedReader(in);
 
         try {
-            isr = new InputStreamReader(in);
-            BufferedReader br = new BufferedReader(isr);
             String identifier;
             while ((identifier = br.readLine()) != null) {
                 final InputStream pluginIn = getInputStreamFromSearchPluginsJar(identifier + ".xml");
@@ -325,15 +328,8 @@ public class SearchEngineManager implements SharedPreferences.OnSharedPreference
         } catch (IOException e) {
             Log.e(LOG_TAG, "Error creating shipped search engine from name: " + name, e);
         } finally {
-            if (isr != null) {
             try {
-                    isr.close();
-                } catch (IOException e) {
-                    // Ignore.
-                }
-            }
-            try {
-                in.close();
+                br.close();
             } catch (IOException e) {
                 // Ignore.
             }
@@ -439,11 +435,47 @@ public class SearchEngineManager implements SharedPreferences.OnSharedPreference
             }
         }
 
-        // Finally, fall back to en-US.
-        url = getSearchPluginsJarURL("en-US", fileName);
+        // Finally, fall back to default locale defined in chrome registry.
+        url = getSearchPluginsJarURL(getFallbackLocale(), fileName);
         return GeckoJarReader.getStream(url);
     }
 
+    /**
+     * Finds a fallback locale in the Gecko chrome registry. If a locale is declared
+     * here, we should be guaranteed to find a searchplugins directory for it.
+     *
+     * This method should only be accessed from the background thread.
+     */
+    private String getFallbackLocale() {
+        if (fallbackLocale != null) {
+            return fallbackLocale;
+        }
+
+        final InputStream in = GeckoJarReader.getStream(getJarURL("!/chrome/chrome.manifest"));
+        final BufferedReader br = getBufferedReader(in);
+
+        try {
+            String line;
+            while ((line = br.readLine()) != null) {
+                // We're looking for a line like "locale global en-US en-US/locale/en-US/global/"
+                // https://developer.mozilla.org/en/docs/Chrome_Registration#locale
+                if (line.startsWith("locale global ")) {
+                    fallbackLocale = line.split(" ", 4)[2];
+                    break;
+                }
+            }
+        } catch (IOException e) {
+            Log.e(LOG_TAG, "Error reading fallback locale from chrome registry", e);
+        } finally {
+            try {
+                br.close();
+            } catch (IOException e) {
+                // Ignore.
+            }
+        }
+        return fallbackLocale;
+    }
+
     /**
      * Gets the jar URL for a file in the searchplugins directory.
      *
@@ -453,6 +485,19 @@ public class SearchEngineManager implements SharedPreferences.OnSharedPreference
      */
     private String getSearchPluginsJarURL(String locale, String fileName) {
         final String path = "!/chrome/" + locale + "/locale/" + locale + "/browser/searchplugins/" + fileName;
+        return getJarURL(path);
+    }
+
+    private String getJarURL(String path) {
         return "jar:jar:file://" + context.getPackageResourcePath() + "!/" + AppConstants.OMNIJAR_NAME + path;
     }
+
+    private BufferedReader getBufferedReader(InputStream in) {
+        try {
+            return new BufferedReader(new InputStreamReader(in, "UTF-8"));
+        } catch (UnsupportedEncodingException e) {
+            // Cannot happen.
+            return null;
+        }
+    }
 }