Fixed a crash that could occur if gtasks encounter auth problems during a background sync

astrid/plugin-src/com/todoroo/astrid/gtasks/auth/GtasksTokenValidator.java

@@ -5,6 +5,7 @@ import java.io.IOException;
 import android.accounts.Account;
 import android.accounts.AccountManager;
 import android.accounts.AccountManagerFuture;
+import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
@@ -85,7 +86,10 @@ public class GtasksTokenValidator {
             token = result.getString(AccountManager.KEY_AUTHTOKEN);
         } else if (result.containsKey(AccountManager.KEY_INTENT)) {
             Intent intent = (Intent) result.get(AccountManager.KEY_INTENT);
-            c.startActivity(intent);
+            if (c instanceof Activity)
+                c.startActivity(intent);
+            else
+                throw new GoogleTasksException(c.getString(R.string.gtasks_error_background_sync_auth));
             return TOKEN_INTENT_RECEIVED;
         } else {
             throw new GoogleTasksException(c.getString(R.string.gtasks_error_accountManager));

astrid/res/values/strings-gtasks.xml

@@ -101,6 +101,8 @@
     <!-- Error when account manager returns no auth token or throws exception -->
     <string name="gtasks_error_accountManager">Error in your phone\'s account manager. Please log out and log back in from the Google Tasks settings.</string>
 
+    <!-- Error when authorization error happens in background sync -->
+    <string name="gtasks_error_background_sync_auth">Error authenticating in background. Please try initiating a sync while Astrid is running.</string>
     
         
 </resources>