Backup/Restore accounts - bugfix - DO NOT MERGE

* Followup to 85d765f4
* Workaround for (HTC bug: 2275383) & (Moto bug: 2226582)
* Restores mSyncKey as null instead of empty string, which is how
  a new account is initialized.  Bug: 2385980
* Cleanup synchronized logic in backup & restore
* Minor cleanups & improved comments

Cherry-picked from master d612717340

src/com/android/email/AccountBackupRestore.java

@@ -49,10 +49,8 @@ public class AccountBackupRestore {
         new Thread() {
             @Override
             public void run() {
-                synchronized(AccountBackupRestore.class) {
                 doBackupAccounts(context, Preferences.getPreferences(context));
             }
-            }
         }.start();
     }
 
@@ -62,10 +60,7 @@ public class AccountBackupRestore {
      */
     public static void restoreAccountsIfNeeded(final Context context) {
         // Don't log here;  This is called often.
-        boolean restored;
-        synchronized(AccountBackupRestore.class) {
-            restored = doRestoreAccounts(context, Preferences.getPreferences(context));
-        }
+        boolean restored = doRestoreAccounts(context, Preferences.getPreferences(context));
         if (restored) {
             // after restoring accounts, register services appropriately
             Log.w(Email.LOG_TAG, "Register services after restoring accounts");
@@ -81,7 +76,8 @@ public class AccountBackupRestore {
      * @param context used to access the provider
      * @param preferences used to access the backups (provided separately for testability)
      */
-    /* package */ static void doBackupAccounts(Context context, Preferences preferences) {
+    /* package */ synchronized static void doBackupAccounts(Context context,
+            Preferences preferences) {
         // 1.  Wipe any existing backup accounts
         Account[] oldBackups = preferences.getAccounts();
         for (Account backup : oldBackups) {
@@ -91,6 +87,8 @@ public class AccountBackupRestore {
         // 2. Identify the default account (if any).  This is required because setting
         // the default account flag is lazy,and sometimes we don't have any flags set.  We'll
         // use this to make it explicit (see loop, below).
+        // This is also the quick check for "no accounts" (the only case in which the returned
+        // value is -1) and if so, we can exit immediately.
         long defaultAccountId = EmailContent.Account.getDefaultAccountId(context);
         if (defaultAccountId == -1) {
             return;
@@ -142,7 +140,8 @@ public class AccountBackupRestore {
      * @param preferences used to access the backups (provided separately for testability)
      * @return true if accounts were restored (meaning services should be restarted, etc.)
      */
-    /* package */ static boolean doRestoreAccounts(Context context, Preferences preferences) {
+    /* package */ synchronized static boolean doRestoreAccounts(Context context,
+            Preferences preferences) {
         boolean result = false;
 
         // 1. Quick check - if we have any accounts, get out
@@ -165,7 +164,7 @@ public class AccountBackupRestore {
                 continue;
             }
             // Restore the account
-            Log.v(Email.LOG_TAG, "Restoring account:" + backupAccount.getDescription());
+            Log.w(Email.LOG_TAG, "Restoring account:" + backupAccount.getDescription());
             EmailContent.Account toAccount =
                 LegacyConversions.makeAccount(context, backupAccount);
 

src/com/android/email/LegacyConversions.java

@@ -529,7 +529,7 @@ public class LegacyConversions {
      *
      * @param context application context
      * @param fromAccount the provider account to be backed up (including transient hostauth's)
-     * @result a legacy Account object ready to be committed to preferences
+     * @return a legacy Account object ready to be committed to preferences
      */
     /* package */ static Account makeLegacyAccount(Context context,
             EmailContent.Account fromAccount) {
@@ -572,6 +572,10 @@ public class LegacyConversions {
      * Conversion from legacy account to provider account
      *
      * Used for backup/restore and for account migration.
+     *
+     * @param context application context
+     * @param fromAccount the legacy account to convert to modern format
+     * @return an Account ready to be committed to provider
      */
     /* package */ static EmailContent.Account makeAccount(Context context, Account fromAccount) {
 
@@ -579,17 +583,17 @@ public class LegacyConversions {
 
         result.setDisplayName(fromAccount.getDescription());
         result.setEmailAddress(fromAccount.getEmail());
-        result.mSyncKey = "";
+        result.mSyncKey = null;
         result.setSyncLookback(fromAccount.getSyncWindow());
         result.setSyncInterval(fromAccount.getAutomaticCheckIntervalMinutes());
-        // result.mHostAuthKeyRecv
-        // result.mHostAuthKeySend;
+        // result.mHostAuthKeyRecv;     -- will be set when object is saved
+        // result.mHostAuthKeySend;     -- will be set when object is saved
         int flags = 0;
         if (fromAccount.isNotifyNewMail())  flags |= EmailContent.Account.FLAGS_NOTIFY_NEW_MAIL;
         if (fromAccount.isVibrate())        flags |= EmailContent.Account.FLAGS_VIBRATE;
         result.setFlags(flags);
         result.setDeletePolicy(fromAccount.getDeletePolicy());
-        // result.setDefaultAccount();
+        // result.setDefaultAccount();  -- will be set by caller, if neededf
         result.mCompatibilityUuid = fromAccount.getUuid();
         result.setSenderName(fromAccount.getName());
         result.setRingtone(fromAccount.getRingtone());

tests/src/com/android/email/AccountBackupRestoreTests.java

@@ -231,6 +231,7 @@ public class AccountBackupRestoreTests extends ProviderTestCase2<EmailProvider>
                 } else {
                     fail("Unexpected restore account name=" + restored.getDisplayName());
                 }
+                checkRestoredTransientValues(restored);
             }
         } finally {
             c.close();
@@ -266,12 +267,27 @@ public class AccountBackupRestoreTests extends ProviderTestCase2<EmailProvider>
                 } else {
                     fail("Unexpected restore account name=" + restored.getDisplayName());
                 }
+                checkRestoredTransientValues(restored);
             }
         } finally {
             c.close();
         }
     }
 
+    /**
+     * Check a given restored account to make sure that transient (non-backed-up) values
+     * are initialized to reasonable values.
+     */
+    private void checkRestoredTransientValues(EmailContent.Account restored) {
+        // sync key == null
+        assertNull(restored.mSyncKey);
+        // hostauth id's are no longer zero or -1
+        assertTrue(restored.mHostAuthKeyRecv > 0);
+        assertTrue(restored.mHostAuthKeySend > 0);
+        // protocol version == null or non-empty string
+        assertTrue(restored.mProtocolVersion == null || restored.mProtocolVersion.length() > 0);
+    }
+
     /**
      * TODO: Test restore EAS accounts, with and without contacts sync
      *

tests/src/com/android/email/LegacyConversionsTests.java

@@ -555,7 +555,7 @@ public class LegacyConversionsTests extends ProviderTestCase2<EmailProvider> {
             throws MessagingException {
         assertEquals(tag + " description", expect.getDescription(), actual.mDisplayName);
         assertEquals(tag + " email", expect.getEmail(), actual.mEmailAddress);
-        assertEquals(tag + " sync key", "", actual.mSyncKey);
+        assertEquals(tag + " sync key", null, actual.mSyncKey);
         assertEquals(tag + " lookback", expect.getSyncWindow(), actual.mSyncLookback);
         assertEquals(tag + " sync intvl", expect.getAutomaticCheckIntervalMinutes(),
                 actual.mSyncInterval);