Crash when activity is left when loading bus data

[michalbednarski]

01-12 10:28:18.753    4124-4298/pl.edu.zut.mad.appwizut2 I/HttpConnect﹕ getPage
01-12 10:28:18.768    4124-4138/pl.edu.zut.mad.appwizut2 E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
    Process: pl.edu.zut.mad.appwizut2, PID: 4124
    java.lang.RuntimeException: An error occurred while executing doInBackground()
            at android.os.AsyncTask$3.done(AsyncTask.java:309)
            at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:354)
            at java.util.concurrent.FutureTask.setException(FutureTask.java:223)
            at java.util.concurrent.FutureTask.run(FutureTask.java:242)
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
            at java.lang.Thread.run(Thread.java:818)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
            at android.preference.PreferenceManager.getDefaultSharedPreferencesName(PreferenceManager.java:375)
            at android.preference.PreferenceManager.getDefaultSharedPreferences(PreferenceManager.java:370)
            at pl.edu.zut.mad.appwizut2.utils.SharedPrefUtils.getSharedPreferences(SharedPrefUtils.java:27)
            at pl.edu.zut.mad.appwizut2.utils.BusTimetable.parseDataFromLoader(BusTimetable.java:156)
            at pl.edu.zut.mad.appwizut2.utils.BusTimetable.access$100(BusTimetable.java:34)
            at pl.edu.zut.mad.appwizut2.utils.BusTimetable$2.foundData(BusTimetable.java:103)
            at pl.edu.zut.mad.appwizut2.network.BusTimetableLoader$GetBusInfo.doInBackground(BusTimetableLoader.java:94)
            at pl.edu.zut.mad.appwizut2.network.BusTimetableLoader$GetBusInfo.doInBackground(BusTimetableLoader.java:71)
            at android.os.AsyncTask$2.call(AsyncTask.java:295)
            at java.util.concurrent.FutureTask.run(FutureTask.java:237)
            at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
            at java.lang.Thread.run(Thread.java:818)